[ADD] playground: add monkey patching example

closes #312
2025-10-06 19:59:41 +07:00 · 2019-10-05 09:00:23 +02:00
87 changed files with 5207 additions and 8705 deletions
@@ -4,7 +4,7 @@ _A no nonsense web framework for structured, dynamic and maintainable applicatio

 ## Project Overview

-The Odoo Web Library (OWL) is a smallish (~18kb gzipped) UI framework intended to
+The Odoo Web Library (OWL) is a smallish (~17kb gzipped) UI framework intended to
 be the basis for the [Odoo](https://www.odoo.com/) Web Client. Owl is a modern
 framework, written in Typescript, taking the best ideas from React and Vue in a
 simple and consistent way. Owl's main features are:
@@ -20,24 +20,25 @@ virtual dom, integrates beautifully with hooks, and the rendering is asynchronou
 **Try it online!** An online playground is available at [https://odoo.github.io/owl/playground](https://odoo.github.io/owl/playground) to let you experiment with the Owl framework. There
 are some code examples to showcase some interesting features.

-Owl is currently mostly stable.  Possible future changes are explained in the
-[roadmap](roadmap.md).
-
 ## Example

 Here is a short example to illustrate interactive components:

 ```javascript
-const { Component, useState } = owl;
-const { xml } = owl.tags;
+import { Component, QWeb, useState } from "owl";
+import { xml } from "owl/tags";

 class Counter extends Component {
  static template = xml`
-    <button t-on-click="state.value++">
+    <button t-on-click="increment">
      Click Me! [<t t-esc="state.value"/>]
    </button>`;

  state = useState({ value: 0 });
+
+  increment() {
+    this.state.value++;
+  }
 }

 class App extends Component {
@@ -50,12 +51,12 @@ class App extends Component {
  static components = { Counter };
 }

-const app = new App();
+const app = new App({ qweb: new QWeb() });
 app.mount(document.body);
 ```

-Note that the counter component is made reactive with the [`useState` hook](doc/reference/hooks.md#usestate).
-Also, all examples here uses the [`xml` helper](doc/reference/tags.md#xml-tag) to define inline templates.
+Note that the counter component is made reactive with the [`useState`](doc/hooks.md#usestate)
+hook. Also, all examples here uses the `xml` helper to define inline templates.
 But this is not mandatory, many applications will load templates separately.

 More interesting examples can be found on the
@@ -86,15 +87,11 @@ find some more information [here](doc/comparison.md).

 ## Documentation

-A complete documentation for Owl can be found here:
+The complete documentation can be found [here](doc/readme.md). The most important sections are:

- [Main documentation page](doc/readme.md).
-
-The most important sections are:
-
- [Quick Start](doc/learning/quick_start.md)
- [Component](doc/reference/component.md)
- [Hooks](doc/reference/hooks.md)
+- [Quick Start](doc/quick_start.md)
+- [Component](doc/component.md)
+- [Hooks](doc/hooks.md)

 Found an issue in the documentation? A broken link? Some outdated information?
 Submit a PR!
@@ -103,8 +100,8 @@ Submit a PR!

 If you want to use a simple `<script>` tag, the last release can be downloaded here:

- [owl-1.0.0-alpha.js](https://github.com/odoo/owl/releases/download/v1.0.0-alpha/owl.js)
- [owl-1.0.0-alpha.min.js](https://github.com/odoo/owl/releases/download/v1.0.0-alpha/owl.min.js)
+- [owl-0.22.0.js](https://github.com/odoo/owl/releases/download/v0.22.0/owl.js)
+- [owl-0.22.0.min.js](https://github.com/odoo/owl/releases/download/v0.22.0/owl.min.js)

 Some npm scripts are available:

@@ -127,6 +124,23 @@ Owl components in an application are used to define a (dynamic) tree of componen
     C   D
 ```

+**Environment:** the root component is special: it is created with an environment,
+which should contain a `QWeb` instance. The environment is then automatically
+propagated to each sub components (and accessible in the `this.env` property).
+
+```js
+const env = { qweb: new QWeb() };
+const app = new App(env);
+app.mount(document.body);
+```
+
+The environment is mostly static. Each application is free to add anything to
+the environment, which is very useful, since this can be accessed by each sub
+component. Some good use case for that is some configuration keys, session
+information or generic services (such as doing rpcs, or accessing local storage).
+Doing it this way means that components are easily testable: we can simply
+create a test environment with mock services.
+
 **State:** each component can manage its own local state. It is a simple ES6
 class, there are no special rules:

@@ -169,12 +183,6 @@ class Counter extends Component {
 }
 ```

-Note that the `t-on-click` handler can even be replaced by an inline statement:
-
-```xml
-    <button t-on-click="state.value++">
-```
-
 **Props:** sub components often needs some information from their parents. This
 is done by adding the required information to the template. This will then be
 accessible by the sub component in the `props` object. Note that there is an
@@ -238,7 +246,7 @@ class Parent extends Component {
 In this example, the `OrderLine` component trigger a `add-to-order` event. This
 will generate a DOM event which will bubble along the DOM tree. It will then be
 intercepted by the parent component, which will then get the line (from the
-`detail` key) and then increment its quantity. See the section on [event handling](doc/reference/component.md#event-handling)
+`detail` key) and then increment its quantity. See the section on [event handling](doc/component.md#event-handling)
 for more details on how events work.

 Note that this example would have also worked if the `OrderLine` component
@@ -30,7 +30,7 @@ btn {
 }
 ```

-will produce a nice flash effect whenever the user clicks (or activates with the
+will produce a nice flash effect whenever the user click (or activate with the
 keyboard) the button.

 ## CSS Transitions
@@ -47,7 +47,7 @@ the lifetime of a node. Since this is not easy to do by hand, Owl `t-transition`
 directive is there to help.

 Whenever a node has a `t-transition` directive, with a `name` value, the following
-sequence of events will happen:
+will happen:

 At node insertion:

@@ -91,5 +91,6 @@ The `t-transition` directive can be applied on a node element or on a component.

 Notes:

-Owl does not support more than one transition on a single node, so the
-`t-transition` expression must be a single value (i.e. no space allowed).
+- more information on animations are available [here](animations.md).
+- Owl does not support more than one transition on a single node, so the
+  `t-transition` expression must be a single value (i.e. no space allowed)
@@ -1,32 +0,0 @@
-# 🦉 Rendering Pipeline 🦉
-
-We explain here how Owl is designed, from the perspective of its rendering
-pipeline.
-
-Warning: these notes are technical by nature, and intended for people working
-on Owl (or interested in understanding its design).
-
-## Overview
-
-A rendering occurs in two phases:
-
- virtual rendering: this generates the virtual dom in memory, asynchronously
- patch: applies a virtual tree to the screen (synchronously)
-
-There are several classes involved in a rendering:
-
- components
- a scheduler
- fibers: small objects containing some metadata, associated with a rendering of
-  a specific component
-
-Components are organized in a dynamic component tree, visible in the user
-interface. Whenever a rendering is initiated in a component `C`:
-
- a fiber is created on `C` with the rendering props information
- the virtual rendering phase starts on C (will asynchronously render all the
-  child components)
- the fiber is added to the scheduler, which will poll continuously, every
-  animation frame, if the fiber is done
- once it is done, the scheduler will call the task callback, which will apply
-  the patch (if it was not cancelled in the meantime).
@@ -3,7 +3,7 @@
 OWL, React and Vue have the same main feature: they allow developers to build
 declarative user interfaces. To do that, all these frameworks uses a virtual dom. However, there are still obviously many differences.

-In this page, we try to highlight some of these differences. Obviously, a lot of
+In this page, we try to highlight some of these differences. Obviously, some
 effort was done to be fair. However, if you disagree with some of the points
 discussed, feel free to open an issue/submit a PR to correct this text.

@@ -16,7 +16,6 @@ discussed, feel free to open an issue/submit a PR to correct this text.
 - [Asynchronous rendering](#asynchronous-rendering)
 - [Reactiveness](#reactiveness)
 - [State Management](#state-management)
- [Hooks](#hooks)

 ## Size

@@ -25,16 +24,11 @@ than React and Vue. Also, jQuery is not the same kind of framework, but it is in

 | Framework                | Size (minified, gzipped) |
 | ------------------------ | ------------------------ |
-| OWL                      | 18kb                     |
+| OWL                      | 16kb                     |
 | Vue + VueX               | 30kb                     |
-| Vue + VueX + Vue Router  | 39kb                     |
 | React + ReactDOM + Redux | 40kb                     |
 | jQuery                   | 30kb                     |

-Note that those comparisons are not entirely fair, because we do not compare
-the same exact set of features. For example, VueX and Vue Router support more
-advanced use cases.
-
 ## Class Based

 Both React and Vue moved away from defining components with classes. They prefer
@@ -46,17 +40,6 @@ contrast, Owl has only one mechanism: class-based components. We believe that Ow
 components are fast enough for all our usecases, and making it as simple as
 possible for developers is more valuable (for us).

-Also, functions or class based components are more than just syntax. Functions
-comes with a mindset of composition and class are about inheritance. Clearly,
-both of these are important mechanisms for reusing code. Also, one does not
-exclude the other.
-
-It certainly looks like the world of UI frameworks is moving toward composition,
-for many very good reasons. Owl is still good at composition (for example,
-Owl supports slots, which is the primary mechanism to make generic reusable
-components). But it can also use inheritance (and this is very important since
-templates can also be inherited with `xpaths` transformations).
-
 ## Tooling/Build step

 OWL is designed to be easy to use in a standalone way. For various reasons,
@@ -67,23 +50,13 @@ be used by simply adding a script tag to a page.
 <script src="owl.min.js" />
 ```

-In comparison, React encourages using JSX, which necessitate a build step, and
-most Vue applications uses single file components, which also necessitate a build step.
+In comparison, React encourages using JSX,
+which necessitate a build step, and most Vue applications uses single file
+components, which also necessitate a build step.

 On the flipside, external tooling may make it harder to use in some case, but it
 also brings a lot of benefits. And React/Vue have both a large ecosystem.

-Note that since Owl is not dependant on any external tool nor libraries, it is
-very easy to integrate into any build toolchain. Also, since we cannot rely on
-additional tools, we made a lot of effort to make the most of the web platform.
-
-For example, Owl uses the standard `xml` parser that comes with every browser.
-Because of that, Owl did not have to write its own template parser. Another
-example is the [`xml`](reference/tags.md#xml-tag) tag helper function, which makes use of
-native template literals to allow in a natural way to write `xml` templates
-directly in the javascript code. This can be easily integrated with editor
-plugins to have autocompletion inside the template.
-
 ## Templating

 OWL uses its own QWeb engine, which compiles templates on the
@@ -106,8 +79,7 @@ into javascript functions. Note that Vue has a separate build which includes the
 template compiler.

 In contrast, most React applications do not use a templating language, but write
-some JSX code, which is precompiled into plain JavaScript by a build step. This
-example is done with the (kind of outdated) React class system:
+some JSX code, which is precompiled into plain JavaScript by a build step.

 ```jsx
 class Clock extends React.Component {
@@ -126,20 +98,6 @@ This has the advantage of having the full power of Javascript, but is less
 structured than a template language. Note that the tooling is quite impressive:
 there is a syntax highlighter for jsx here on github!

-By comparison, here is the equivalent Owl component, written with the
-[`xml`](reference/tags.md#xml-tag) tag helper:
-
-```js
-class Clock extends Component {
-  static template = xml`
-      <div>
-        <h1>Hello, world!</h1>
-        <h2>It is {props.date.toLocaleTimeString()}.</h2>
-      </div>
-    `;
-}
-```
-
 ## Asynchronous Rendering

 This is actually a big difference between OWL and React/Vue: components in OWL
@@ -169,14 +127,12 @@ This may be dangerous (to stop the rendering waiting for the network), but it is
 extremely powerful as well, as demonstrated by the Odoo Web Client.

 Lazy loading static libraries can obviously be done with React/Vue, but it is
-more convoluted. For example, in Vue, you need to use a dynamic import keyword
-that needs to be transpiled at build time in order for the component to be loaded
-asynchronously (see [the documentation](https://vuejs.org/v2/guide/components-dynamic-async.html#Async-Components)).
+more convoluted.

 ## Reactiveness

 React has a simple model: whenever the state changes, it is
-replaced with a new state (via the `setState` method). Then, the DOM is patched.
+replaced with a new state (via the setState method). Then, the DOM is patched.
 This is simple, efficient, and a little bit awkward to write.

 Vue is a little bit different: it replace magically the properties in the state
@@ -251,95 +207,30 @@ keeps track of who get data, and retrigger a render when it was changed.
 Owl store is a little bit like a mix of redux and vuex: it has actions (but not
 mutations), and like VueX, it keeps track of the state changes. However, it does
 not notify a component when the state changes. Instead, components need to connect
-to the store like in redux, with the `useStore` hook (see the [store documentation](reference/store.md#connecting-a-component)).
+to the store like in redux, by inheriting the `ConnectedComponent` class.

 ```javascript
 const actions = {
  increment({ state }, val) {
-    state.counter.value += val;
+    state.counter += val;
  }
 };

 const state = {
-  counter: { value: 0 }
+  counter: 0
 };
 const store = new owl.Store({ state, actions });

-class Counter extends Component {
-  static template = xml`
-      <button t-name="Counter" t-on-click="dispatch('increment')">
-        Click Me! [<t t-esc="counter.value"/>]
-      </button>`;
-  counter = useStore(state => state.counter);
-  dispatch = useDispatch();
-}
-
-owl.config.env.store = store;
-const counter = new Counter();
-```
-
-## Hooks
-
-[Hooks](https://reactjs.org/docs/hooks-intro.html#motivation) recently took over
-the React world. They solve a lot of seemingly unconnected problems: attach
-reusable behavior to a component, in a composable way, extract stateful logic
-from a component or reuse stateful logic between component, without changing your
-component hierarchy.
-
-Here is an example of the React `useState` hook:
-
-```js
-import React, { useState } from "react";
-
-function Example() {
-  // Declare a new state variable, which we'll call "count"
-  const [count, setCount] = useState(0);
-
-  return (
-    <div>
-      <p>You clicked {count} times</p>
-      <button onClick={() => setCount(count + 1)}>Click me</button>
-    </div>
-  );
-}
-```
-
-Because of the way React designed the hooks API, they only work for functional
-components. But in that case, they really are powerful. Every major React library
-is in the process of redesigning their API with hooks (for example,
-[Redux](https://react-redux.js.org/next/api/hooks)).
-
-Vue 2 does not have hooks, but the Vue project is working on its next version,
-which will feature its new [composition API](https://vue-composition-api-rfc.netlify.com/).
-This work is based on the new ideas introduced by React hooks.
-
-From the way React and Vue introduce their hooks, it may look like hooks are not
-compatible with class components. However, this is not the case, as shown by
-Owl [hooks](reference/hooks.md). They are inspired by both React and Vue. For example,
-the `useState` hook is named after React, but its API is closer to the `reactive`
-Vue hook.
-
-Here is what the `Counter` example above look like in Owl:
-
-```js
-import { Component, Owl } from "owl";
-import { xml } from "owl/tags";
-
-class Example extends Component {
-  static template = xml`
-      <div>
-        <p>You clicked {count.value} times</p>
-        <button t-on-click="increment">Click me</button>
-      </div>`;
-
-  count = useState({ value: 0 });
-
+class Counter extends owl.ConnectedComponent {
+  static mapStoreToProps(state) {
+    return {
+      value: state.counter
+    };
+  }
  increment() {
-    this.state.value++;
+    this.env.store.dispatch("increment");
  }
 }
-```

-Since the Owl framework had hooks from early in its life, its main APIs
-are designed to be interacted with hooks from the start. For example, the
-`Context` and `Store` abstractions.
+const counter = new Counter({ store, qweb });
+```
@@ -11,6 +11,7 @@
  - [Methods](#methods)
  - [Lifecycle](#lifecycle)
  - [Root Component](#root-component)
+  - [Environment](#environment)
  - [Composition](#composition)
  - [Event Handling](#event-handling)
  - [Form Input Bindings](#form-input-bindings)
@@ -28,7 +29,7 @@

 OWL components are the building blocks for user interface. They are designed to be:

-1. **declarative:** the user interface should be described in terms of the state
+1. **declarative:** the user interface should be described in term of the state
   of the application, not as a sequence of imperative steps.

 2. **composable:** each component can seamlessly be created in a parent component by
@@ -71,7 +72,7 @@ class ClickCounter extends owl.Component {
 Note that this code is written in ESNext style, so it will only run on the
 latest browsers without a transpilation step.

-This example shows how a component should be defined: it simply subclasses the
+This example show how a component should be defined: it simply subclasses the
 Component class. If no static `template` key is defined, then
 Owl will use the component's name as template name. Here,
 a state object is defined, by using the `useState` hook. It is not mandatory to use the state object, but it is certainly encouraged. The result of the `useState` call is
@@ -79,87 +80,33 @@ a state object is defined, by using the `useState` hook. It is not mandatory to

 ## Reference

-An Owl component is a small class which represents a component or some UI element.
-It exists in the context of an [environment](environment.md) (`env`), which is propagated from a
-parent to its children. The environment needs to have a [QWeb](qweb.md) instance, which
+An Owl component is a small class which represent a component or some UI element.
+It exists in the context of an environment (`env`), which is propagated from a
+parent to its children. The environment needs to have a QWeb instance, which
 will be used to render the component template.

 Be aware that the name of the component may be significant: if a component does
 not define a `template` key, then Owl will lookup in QWeb to
-find a template with the component name (or one of its ancestors).
+find a template with the component name (or one of its ancestor).

 ### Reactive system

-OWL components are normal javascript classes. So, changing a component internal
-state does nothing more:
+OWL components can be made reactive by observing some part of their state. See the [hooks](hooks.md) section for more details.

-```js
-class Counter extends Component {
-  static template = xml`<div t-on-click="increment"><t t-esc="state.value"/></div>`;
-  state = { value: 0 };
-
-  increment() {
-    this.state.value++;
-  }
-}
-```
-
-Clicking on the `Counter` component defined above will call the `increment`
-method, but it will not rerender the component. To fix that, one could add an
-explicit call to `render` in `increment`:
-
-```js
-    increment() {
-        this.state.value++;
-        this.render();
-    }
-```
-
-However, it may be simple in this case, but it quickly become cumbersome, as a
-component get more complex, and its internal state is modified by more than one
-method.
-
-A better way is to use the reactive system: by using the `useState` hook (see the
-[hooks](hooks.md) section for more details), one can make Owl react to state
-changes. The `useState` hook generates a proxy version of an object
+The main idea is that the `useState` hook generate a proxy version of an object
 (this is done by an [observer](observer.md)), which allows the component to
-react to any change. So, the `Counter` example above can be improved like this:
+react to any change.

-```js
+```javascript
 const { useState } = owl.hooks;

-class Counter extends Component {
-  static template = xml`<div t-on-click="increment"><t t-esc="state.value"/></div>`;
-  state = useState({ value: 0 });
-
-  increment() {
-    this.state.value++;
-  }
+class SomeComponent extends owl.Component {
+  state = useState({ a: 0, b: 1 });
 }
 ```

-Obviously, we can call the `useState` hook more than once:
-
-```js
-const { useState } = owl.hooks;
-
-class Counter extends Component {
-  static template = xml`
-      <div>
-        <span t-on-click="increment(counter1)"><t t-esc="counter1.value"/></span>
-        <span t-on-click="increment(counter2)"><t t-esc="counter2.value"/></span>
-      </div>`;
-  counter1 = useState({ value: 0 });
-  counter2 = useState({ value: 0 });
-
-  increment(counter) {
-    counter.value++;
-  }
-}
-```
-
-Note that hooks are subject to one important [rule](hooks.md#one-rule): they need
-to be called in the constructor.
+Note that there is an important limitation: hooks need to be called in the
+constructor.

 ### Properties

@@ -168,23 +115,10 @@ to be called in the constructor.

 - **`env`** (Object): the component environment, which contains a QWeb instance.

- **`props`** (Object): this is an object containing all the properties given by
-  the parent to a child component. For example, in the following situation,
-  the parent component gives a `user` and a `color` value to the `ChildComponent`.
-
-  ```xml
-    <div>
-      <ChildComponent user="state.user" color="color">
-    </div>
-  ```
-
-  Note that `props` are owned by the parent, not by the component.
-  As such, it should not ever be modified by the component (otherwise you risk
-  unintended effects, since the parent may not be aware of the change)!!
-
-  The `props` can be modified dynamically by the parent. In that case, the
-  component will go through the following lifecycle methods: `willUpdateProps`,
-  `willPatch` and `patched`.
+- **`props`** (Object): this is an object given (in the constructor) by the parent
+  to configure the component. It can be dynamically changed later by the parent,
+  in some case. Note that `props` are owned by the parent, not by the component.
+  As such, it should not ever be modified by the component!!

 ### Static Properties

@@ -228,11 +162,6 @@ to be called in the constructor.
  }
  ```

-There is another static property defined on the `Component` class: `current`.
-This property is set to the currently being defined component (in the constructor).
-This is the way [hooks](hooks.md) are able to get a reference to the target
-component.
-
 ### Methods

 We explain here all the public methods of the `Component` class.
@@ -248,7 +177,7 @@ We explain here all the public methods of the `Component` class.
  we know that its state (or something in the environment, or ...) has changed.
  In that case, it should simply set to `true`.

- **`unmount()`**: in case a component needs to be detached/removed from the DOM, this
+- **`unmount()`**: in case a component need to be detached/removed from the DOM, this
  method can be used. Most applications should not call `unmount`, this is more
  useful to the underlying component system.

@@ -266,6 +195,11 @@ We explain here all the public methods of the `Component` class.
  always return true. This is an optimization, similar to React's `shouldComponentUpdate`. Most of the time, this should not be used, but it
  can be useful if we are handling large number of components.

+- **`updateEnv(nextEnv)`**: update the environment of a component and all its
+  children. This forces a complete rerender. For example, this could be useful
+  if we have a `isMobile` key in the environment, to decide if we want a mobile
+  interface or a destkop one.
+
 - **`destroy()`**. As its name suggests, this method will remove the component,
  and perform all necessary cleanup, such as unmounting the component, its children,
  removing the parent/children relationship. This method should almost never be
@@ -369,8 +303,8 @@ will slightly slow down the component.
 #### `willUpdateProps(nextProps)`

 The willUpdateProps is an asynchronous hook, called just before new props
-are set. This is useful if the component needs to perform an asynchronous task,
-depending on the props (for example, assuming that the props are
+are set. This is useful if the component needs some asynchronous task
+performed, depending on the props (for example, assuming that the props are
 some record Id, fetching the record data).

 ```javascript
@@ -385,13 +319,14 @@ and performs a similar job).
 #### `willPatch()`

 The willPatch hook is called just before the DOM patching process starts.
-It is not called on the initial render. This is useful to read
+It is not called on the initial render. This is useful to read some
 information from the DOM. For example, the current position of the
 scrollbar.

 Note that modifying the state is not allowed here. This method is called just
 before an actual DOM patch, and is only intended to be used to save some local
-DOM state. Also, it will not be called if the component is not in the DOM.
+DOM state. Also, it will not be called if the component is not in the DOM (this can
+happen with components with `t-keepalive`).

 #### `patched(snapshot)`

@@ -401,17 +336,17 @@ likely via a change in its state/props or environment).
 This method is not called on the initial render. It is useful to interact
 with the DOM (for example, through an external library) whenever the
 component was patched. Note that this hook will not be called if the compoent is
-not in the DOM.
+not in the DOM (this can happen with components with `t-keepalive`).

-Updating the component state in this hook is possible, but not encouraged.
-One needs to be careful, because updates here will create an additional rendering, which in
-turn will cause other calls to the `patched` method. So, we need to be particularly
+Updating the compoent state in this hook is possible, but not encouraged.
+One need to be careful, because updates here will cause rerender, which in
+turn will cause other calls to patched. So, we need to be particularly
 careful at avoiding endless cycles.

 #### `willUnmount()`

 willUnmount is a hook that is called each time just before a component is unmounted from
-the DOM. This is a good place to remove listeners, for example.
+the DOM. This is a good place to remove some listeners, for example.

 ```javascript
  mounted() {
@@ -428,7 +363,7 @@ This is the opposite method of `mounted`.

 The `catchError` method is useful when we need to intercept and properly react
 to (rendering) errors that occur in some sub components. See the section on
-[error handling](#error-handling).
+[error handling](#error-handling)

 ### Root Component

@@ -439,12 +374,49 @@ of an Owl application has to be created manually:
 ```js
 class App extends owl.Component { ... }

-const app = new App();
+const qweb = new owl.QWeb(TEMPLATES);
+const env = { qweb: qweb };
+const app = new App(env);
 app.mount(document.body);
 ```

-The root component does not have a parent nor props. It will be setup with an
-[environment](environment.md) (located in `owl.config.env`).
+The root component needs an environment.
+
+### Environment
+
+In Owl, an environment is an object with a `qweb` key, which has to be a
+[QWeb](qweb.md) instance. This qweb instance will be used to render everything.
+
+The environment is meant to contain (mostly) static global information and
+methods for the whole application. For example, settings keys (`mode` to determine
+if we are in desktop or mobile mode, or `theme`: dark or light), `rpc` methods,
+session information, ...
+
+The environment will be given to each child, unchanged, in the `env` property.
+This can be very useful to share common information/methods. For example, all
+rpcs can be made through a `rpc` method in the environment. This makes it very
+easy to test a component.
+
+Updating the environment is not as simple as changing a component's state: its
+content is not observed, so updates will not be reflected immediately in the
+user interface. There is however a mechanism to force root widgets to rerender
+themselves whenever the environment is modified: one only needs to call the
+`forceUpdate` method on the QWeb instance. For example, a responsive environment
+could be done like this:
+
+```js
+function setupResponsivePlugin(env) {
+  const isMobile = () => window.innerWidth <= 768;
+  env.isMobile = isMobile();
+  const updateEnv = owl.utils.debounce(() => {
+    if (env.isMobile !== isMobile()) {
+      env.isMobile = !env.isMobile;
+      env.qweb.forceUpdate();
+    }
+  }, 15);
+  window.addEventListener("resize", updateEnv);
+}
+```

 ### Composition

@@ -500,7 +472,7 @@ constructor. This will be assigned to the `props` variable, which can be accesse
 on the component (and also, in the template). Whenever the state is updated, then
 the sub component will also be updated automatically.

-Note that there are restrictions on valid prop names: `class`, `style` and any
+Note that there are some restrictions on prop names: `class`, `style` and any
 string which starts with `t-` are not allowed.

 It is not common, but sometimes we need a dynamic component name and/or dynamic props. In this case,
@@ -559,7 +531,7 @@ class App extends Component<any, any, any> {
 In this example, the component `App` selects dynamically the concrete sub
 component class.

-**CSS and style:** Owl allows the parent to declare
+**CSS and style:** there is some specific support to allow the parent to declare
 additional css classes or style for the sub component: css declared in `class`, `style`, `t-att-class` or `t-att-style` will be added to the
 root component element.

@@ -572,7 +544,7 @@ root component element.
 Warning: there is a small caveat with dynamic class attributes: since Owl needs
 to be able to add/remove proper classes whenever necessary, it needs to be aware
 of the possible classes. Otherwise, it will not be able to make the difference
-between a valid css class added by the component, or other custom code, and a
+between a valid css class added by the component, or some custom code, and a
 class that need to be removed. This is why we only support the explicit syntax
 with a class object:

@@ -582,7 +554,7 @@ with a class object:

 ### Event Handling

-In a component's template, it is useful to be able to register handlers on DOM
+In a component's template, it is useful to be able to register handlers on some
 elements to some specific events. This is what makes a template _alive_. There
 are four different use cases.

@@ -638,30 +610,6 @@ to event `menu-loaded` will receive the payload in its `someMethod` handler

 By convention, we use KebabCase for the name of _business_ events.

-The `t-on` directive allows to prebind its arguments. For example,
-
-```xml
-<button t-on-click="someMethod(expr)">Do something</button>
-```
-
-Here, `expr` is a valid Owl expression, so it could be `true` or some variable
-from the rendering context.
-
-One can also directly specify inline statements. For example,
-
-```xml
-<button t-on-click="state.counter++">Increment counter</button>
-```
-
-Here, `state` must be defined in the rendering context (typically the component)
-as it will be translated to:
-
-```js
-button.addEventListener("click", () => {
-  component.state.counter++;
-});
-```
-
 In order to remove the DOM event details from the event handlers (like calls to
 `event.preventDefault`) and let them focus on data logic, _modifiers_ can be
 specified as additional suffixes of the `t-on` directive.
@@ -681,14 +629,14 @@ the order may matter. For instance `t-on-click.prevent.self` will prevent all
 clicks while `t-on-click.self.prevent` will only prevent clicks on the element
 itself.

-Finally, empty handlers are tolerated as they could be defined only to apply
-modifiers. For example,
+The `t-on` directive also allows to prebind some arguments. For example,

 ```xml
-<button t-on-click.stop="">Do something</button>
+<button t-on-click="someMethod(expr)">Do something</button>
 ```

-This will simply stop the propagation of the event.
+Here, `expr` is a valid Owl expression, so it could be `true` or some variable
+from the rendering context.

 ### Form Input Bindings

@@ -764,12 +712,12 @@ The `t-model` directive works with `<input>`, `<input type="checkbox">`,
 </div>
 ```

-Like event handling, the `t-model` directive accepts the following modifiers:
+Like event handling, the `t-model` directive accepts some modifiers:

 | Modifier  | Description                                                          |
 | --------- | -------------------------------------------------------------------- |
 | `.lazy`   | update the value on the `change` event (default is on `input` event) |
-| `.number` | try to parse the value to a number (using `parseFloat`)              |
+| `.number` | tries to parse the value to a number (using `parseFloat`)            |
 | `.trim`   | trim the resulting value                                             |

 For example:
@@ -785,67 +733,27 @@ Note: the online playground has an example to show how it works.

 ### `t-key` Directive

-Even though Owl tries to be as declarative as possible, the DOM does not fully
-expose its state declaratively in the DOM tree. For example, the scrolling state,
-the current user selection, the focused element or the state of an input are not
-set as attribute in the DOM tree. This is why we use a virtual dom
-algorithm to keep the actual DOM node as much as possible.
+Even though Owl tries to be as declarative as possible, some DOM state is still
+locked inside the DOM: for example, the scrolling state, the current user selection,
+the focused element or the state of an input. This is why we use a virtual dom
+algorithm to keep the actual DOM node as much as possible. However, this is
+sometimes not enough, and we need to help Owl decide if an element is actually
+the same, or is different. The `t-key` directive is used to give an identity to an element.

-However, in some situations, this is not enough, and we need to help Owl decide
-if an element is actually the same, or is a different element with the same
-properties.
+There are three main use cases:

-Consider the following situation: we have a list of two items `[{text: "a"}, {text: "b"}]`
-and we render them in this template:
+- _elements in a list_:

-```xml
-<p t-foreach="items" t-as="item"><t t-esc="item.text"/></p>
-```
+  ```xml
+    <span t-foreach="todos" t-as="todo" t-key="todo.id">
+        <t t-esc="todo.text" />
+    </span>
+  ```

-The result will be two `<p>` tags with text `a` and `b`. Now, if we swap them,
-and rerender the template, Owl needs to know what the intent is:
+- _`t-if`/`t-else`_

- should Owl actually swap the DOM nodes,
- or should it keep the DOM nodes, but with an updated text content?
-
-This might look trivial, but it actually matters. These two possibilities lead
-to different results in some cases. For example, if the user selected the text
-of the first `p`, swapping them will keep the selection while updating the
-text content will not.
-
-There are many other cases where this is important: `input` tags with their
-value, css classes and animations, scroll position...
-
-So, the `t-key` directive is used to give an identity to an element. It allows
-Owl to understand if different elements of a list are actually different or not.
-
-The above example could be modified by adding an ID: `[{id: 1, text: "a"}, {id: 2, text: "b"}]`.
-Then, the template could look like this:
-
-```xml
-<p t-foreach="items" t-as="item" t-key="item.id"><t t-esc="item.text"/></p>
-```
-
-The `t-key` directive is useful for lists (`t-foreach`). A key should be
-a unique number or string (objects will not work: they will be cast to the
-`"[object Object]"` string, which is obviously not unique).
-
-Also, the key can be set on a `t` tag or on its children. The following variations
-are all equivalent:
-
-```xml
-<p t-foreach="items" t-as="item" t-key="item.id">
-  <t t-esc="item.text"/>
-</p>
-
-<t t-foreach="items" t-as="item" t-key="item.id">
-  <p t-esc="item.text"/>
-</t>
-
-<t t-foreach="items" t-as="item">
-  <p t-key="item.id" t-esc="item.text"/>
-</t>
-```
+- _animations_: give a different identity to a component. Ex: thread id with
+  animations on add/remove message.

 ### Semantics

@@ -939,7 +847,7 @@ Here is what Owl will do:
 As an application becomes complex, it may be quite unsafe to define props in an informal way. This leads to two issues:

 - hard to tell how a component should be used, by looking at its code.
- unsafe, it is easy to send wrong props into a component, either by refactoring a component, or one of its parents.
+- unsafe, it is easy to send wrong props into a component, either by refactoring a component, or one of its parent.

 A props type system would solve both issues, by describing the types and shapes
 of the props. Here is how it works in Owl:
@@ -947,7 +855,7 @@ of the props. Here is how it works in Owl:
 - `props` key is a static key (so, different from `this.props` in a component instance)
 - it is optional: it is ok for a component to not define a `props` key.
 - props are validated whenever a component is created/updated
- props are only validated in `dev` mode (see [config page](config.md#mode))
+- props are only validated in `dev` mode (see [tooling page](tooling.md#development-mode))
 - if a key does not match the description, an error is thrown
 - it validates keys defined in (static) `props`. Additional keys given by the
  parent will cause an error.
@@ -1164,9 +1072,9 @@ Here are a few tips on how to work with asynchronous components:
   synchronous renderings
 3. Lazy loading external libraries is a good use case for async rendering. This
   is mostly fine, because we can assume that it will only takes a fraction of a
-   second, and only once (see [`owl.utils.loadJS`](utils.md#loadjs))
-4. For all the other cases, the [`AsyncRoot`](misc.md#asyncroot) component is there to help you. When
-   this component is met, a new rendering
+   second, and only once (see `owl.utils.loadJS`)
+4. For all the other cases, the `t-asyncroot` directive (to use alongside
+   `t-component`) is there to help you. When this directive is met, a new rendering
   sub tree is created, such that the rendering of that component (and its
   children) is not tied to the rendering of the rest of the interface. It can
   be used on an asynchronous component, to prevent it from delaying the
@@ -1178,9 +1086,7 @@ Here are a few tips on how to work with asynchronous components:
   ```xml
   <div t-name="ParentComponent">
     <SyncChild />
-     <AsyncRoot>
-        <AsyncChild/>
-     </AsyncRoot>
+     <AsyncChild t-asyncroot="1"/>
   </div>
   ```

@@ -1197,7 +1103,7 @@ from lifecycle hooks): the `catchError` hook.

 Whenever the `catchError` lifecycle hook is implemented, all errors coming from
 sub components rendering and/or lifecycle method calls will be caught and given
-to the `catchError` method. This allows us to properly handle the error, and to
+to the `catchError` method. This allow us to properly handle the error, and to
 not break the application.

 For example, here is how we could implement an `ErrorBoundary` component:
@@ -5,7 +5,7 @@ parts of the code. Owl has a very simple bus class, which manages subscriptions,
 triggering events, and callbacks.

 ```js
-const bus = new owl.core.EventBus();
+const bus = new owl.EventBus();

 bus.on("some-event", null, function(...args) {
  console.log(...args);
@@ -12,15 +12,8 @@
  - [`onWillUnmount`](#onwillunmount)
  - [`onWillPatch`](#onwillpatch)
  - [`onPatched`](#onpatched)
-  - [`onWillStart`](#onwillstart)
-  - [`onWillUpdateProps`](#onwillupdateprops)
-  - [`useContext`](#usecontext)
  - [`useRef`](#useref)
-  - [`useSubEnv`](#usesubenv)
-  - [`useStore`](#usestore)
-  - [`useDispatch`](#usedispatch)
-  - [`useGetters`](#usegetters)
-  - [Making customized hooks](#making-customized-hooks)
+  - [`useSubEnv`](#useSubEnv)

 ## Overview

@@ -35,7 +28,7 @@ Owl hooks serve the same purpose, except that they work for class components
 there seems to be the misconception that hooks are in opposition to class. This
 is clearly not true, as shown by Owl hooks).

-Hooks work beautifully with Owl components: they solve the problems mentioned
+Hooks works beautifully with Owl components: they solve the problems mentioned
 above, and in particular, they are the perfect way to make your component
 reactive.

@@ -127,7 +120,7 @@ class SomeComponent extends Component {

 ### One rule

-There is only one rule: every hook for a component has to be called in the
+There is only one rule: every hook for a component have to be called in the
 constructor (or in class fields):

 ```js
@@ -152,14 +145,10 @@ class SomeComponent extends Component {
 }
 ```

-In a hook, the `Component.current` static property is the reference to the
-component instance that is currently being created. Hooks need to be called in
-the constructor to ensure that this reference is properly set.
-
 ### `useState`

-The `useState` hook is certainly the most important hook for Owl components:
-this is what allows a component to be reactive, to react to state change.
+The `useState` hook is certainly the most important hooks for Owl components:
+this is what enables component to be reactive, to react to state change.

 The `useState` hook has to be given an object or an array, and will return
 an observed version of it (using a `Proxy`).
@@ -181,90 +170,31 @@ class Counter extends owl.Component {
 }
 ```

-It is important to remember that `useState` only works with objects or arrays. It
-is necessary, since Owl needs to react to a change in state.
-
 ### `onMounted`

-`onMounted` is not a user hook, but is a building block designed to help make useful
+`onMounted` is not an user hook, but is a building block designed to help make useful
 abstractions. `onMounted` registers a callback, which will be called when the component
 is mounted (see example on top of this page).

 ### `onWillUnmount`

-`onWillUnmount` is not a user hook, but is a building block designed to help make useful
+`onWillUnmount` is not an user hook, but is a building block designed to help make useful
 abstractions. `onWillUnmount` registers a callback, which will be called when the component
 is unmounted (see example on top of this page).

+
 ### `onWillPatch`

-`onWillPatch` is not a user hook, but is a building block designed to help make useful
+`onWillPatch` is not an user hook, but is a building block designed to help make useful
 abstractions. `onWillPatch` registers a callback, which will be called just
 before the component patched.

 ### `onPatched`

-`onPatched` is not a user hook, but is a building block designed to help make useful
+`onPatched` is not an user hook, but is a building block designed to help make useful
 abstractions. `onPatched` registers a callback, which will be called just
 after the component patched.

-### `onWillStart`
-
-`onWillStart` is an asynchronous hook. This means that the function registered
-in the hook will be run just before the component is first rendered and can return a
-promise, to express the fact that it is an asynchronous operation.
-
-Note that if there are more than one `onWillStart` registered callback, then they
-will all be run in parallel.
-
-It can be used to load some initial data. For example, the following hook will
-automatically load some data from the server, and return an object that will
-be ready whenever the component is rendered:
-
-```js
-function useLoader() {
-  const component = Component.current;
-  const record = useState({});
-  onWillStart(async () => {
-    const recordId = component.props.id;
-    Object.assign(record, await fetchSomeRecord(recordId));
-  });
-  return record;
-}
-```
-
-Note that this example does not update the record value whenever props are
-updated. For that situation, we need to use the `onWillUpdateProps` hook.
-
-### `onWillUpdateProps`
-
-Just like `onWillStart`, `onWillUpdateProps` is an asynchronous hook. It is
-designed to be run whenever the component props are updated. This could be
-useful to perform some asynchronous task such as fetching updated data.
-
-```js
-function useLoader() {
-  const component = Component.current;
-  const record = useState({});
-
-  async function updateRecord(id) {
-    Object.assign(record, await fetchSomeRecord(id));
-  }
-
-  onWillStart(() => updateRecord(component.props.id));
-  onWillUpdateProps(nextProps => updateRecord(nextProps.id));
-
-  return record;
-}
-```
-
-Note that if there are more than one `onWillUpdateProps` registered callback,
-then they will all be run in parallel.
-
-### `useContext`
-
-See [`useContext`](context.md#usecontext) for reference documentation.
-
 ### `useRef`

 The `useRef` hook is useful when we need a way to interact with some inside part
@@ -308,7 +238,7 @@ The `t-ref` directive also accepts dynamic values with string interpolation
 <div t-ref="component_{{someCondition ? '1' : '2'}}"/>
 ```

-Here, the references need to be set like this:
+Here, the references needs to be set like this:

 ```js
 this.ref1 = useRef("component_1");
@@ -321,11 +251,11 @@ If this is not the case, accessing `el` or `comp` on it will return `null`.
 ### `useSubEnv`

 The environment is sometimes useful to share some common information between
-all components. But sometimes, we want to _scope_ that knowledge to a subtree.
+all components.  But sometimes, we want to *scope* that knowledge to a subtree.

 For example, if we have a form view component, maybe we would like to make some
-`model` object available to all sub components, but not to the whole application.
-This is where the `useSubEnv` hook may be useful: it lets a component add some
+`model` object available to all sub component, but not to the whole application.
+This is where the `useSubEnv` hook may be useful: it let a component add some
 information to the environment in a way that only the component and its children
 can access it:

@@ -341,85 +271,5 @@ class FormComponent extends Component {

 The `useSubEnv` takes one argument: an object which contains some key/value that
 will be added to the parent environment. Note that it will extend, not replace
-the parent environment. And of course, the parent environment will not be
-affected.
-
-### `useStore`
-
-The `useStore` hook is the entry point for a component to connect to the store.
-See the [store documentation](store.md) for more information.
-
-### `useDispatch`
-
-The `useDispatch` hook is the way for components to get a reference to the store
-`dispatch` function. See the [store documentation](store.md) for more information.
-
-### `useGetters`
-
-The `useGetters` hook is the way for components to get a reference to the store
-getters. See the [store documentation](store.md) for more information.
-
-### Making customized hooks
-
-Hooks are a wonderful way to organize the code of a complex component by feature
-instead of by lifecycle methods. They are like mixins, except that they can be
-easily composed together.
-
-But, like every good things in life, hooks should be used with moderation. They are
-not the solution to every problem.
-
- they may be overkill: if your component needs to perform some action specific
-  to itself (so, the specific code does not need to be shared), there is nothing
-  wrong with a simple class method:
-
-  ```js
-  // maybe overkill
-  class A extends Component {
-    constructor(...args) {
-      super(...args);
-      useMySpecificHook();
-    }
-  }
-
-  // ok
-  class B extends Component {
-    constructor(...args) {
-      super(...args);
-      this.performSpecificTask();
-    }
-  }
-  ```
-
-  Note that the second solution is easier to extend in sub components.
-
- they may be harder to test: if a customized hook injects some external side
-  effect dependency, then it is harder to test without doing some non obvious
-  manipulation. For example, assume that we want to give a reference to a
-  router in a `useRouter` hook. We could do this:
-
-  ```js
-  const router = new Router(...);
-
-  function useRouter() {
-      return router;
-  }
-  ```
-
-  As you can see, this does not _hook_ into the internal of the component. It
-  simply returns a global object, which is difficult to mock.
-
-  A better way would be to do something like this: get the reference from the
-  environment.
-
-  ```js
-  function useRouter() {
-    return Component.current.env.router;
-  }
-  ```
-
-  This means that we give control to the application developer to create the
-  router, which is good, so they can set it up, subclass it, ... And then, to
-  test our components, we can just add a mock router in the environment.
-
-Note: the code above makes use of the `Component.current` property. This is the
-way hooks are able to get a reference to the component currently being created.
+the parent environment.  And of course, the parent environment will not be
+affected.
@@ -1,48 +0,0 @@
-# 🦉 Environment 🦉
-
-An environment is an object which contains a [`QWeb` instance](../reference/qweb.md).
-Whenever a root component is created, it is assigned an environment (see the
-reference section on [environment](../reference/environment.md). This environment
-is then automatically given to each sub components (and accessible in the `this.env` property).
-
-The environment is mostly static. Each application is free to add anything to
-the environment, which is very useful, since this can be accessed by each sub
-component.
-
-Some good use cases for the environment is:
-
- some configuration keys,
- session information,
- generic services (such as doing rpcs, or accessing local storage).
-
-Doing it this way means that components are easily testable: we can simply
-create a test environment with mock services.
-
-For example:
-
-
-```js
-async function myEnv() {
-    const templates = await loadTemplates();
-    const qweb = new QWeb({templates});
-    const session = getSession();
-
-    return {
-        _t: myTranslateFunction,
-        session: session,
-        qweb: qweb,
-        services: {
-            localStorage: localStorage,
-            rpc: rpc,
-        },
-        debug: false,
-        inMobileMode: true,
-    };
-}
-
-async function start() {
-    owl.config.env = await myEnv();
-    const app = new App();
-    await app.mount(document.body);
-}
-```
@@ -0,0 +1,20 @@
+# 🦉 Observer 🦉
+
+Owl need to be able to react to state changes. For example, whenever the state
+of a component is changed, we need to rerender it. To help with that, we have
+an Observer class. Its job is to observe some object state, and react to any
+change. To do that, it recursively replace all keys of the observed state by
+getters and setters.
+
+For example, this code will display `update` in the console:
+
+```javascript
+const observer = new owl.Observer();
+observer.notifyCB = () => console.log("update");
+const obj = observer.observe({ a: { b: 1 } });
+
+obj.a.b = 2;
+```
+
+The observer is implemented with the native `Proxy` object. Note that this
+means that it will not work on older browsers.
@@ -2,17 +2,8 @@

 ## Static Server

-Let us assume that we have a static server running somewhere. Let us start by
-adding an html page with a few extra files:
-
-```
-my-app/
-    index.html
-    app.css
-    app.js
-    owl-X.Y.Z.js
-    templates.xml
-```
+Let us assume that we have a static server running somewhere. We could then
+simply add an html page with a few extra files.

 ### HTML and CSS

@@ -64,7 +55,7 @@ To build an application (or a sub-part of an application), we need two things:

 - an environment: it is the global context in which we are working. It needs to
  contain a QWeb instance (preloaded with templates), and anything else that we
-  need. In practice, it could be used to contain some user session information, some
+  need. In practice, it could context some user session information, some
  configuration keys (for example, isMobile = true/false if we are in mobile mode).

 - a description of the user interface: there should be a root component, which can
@@ -85,7 +76,10 @@ const useState = owl.hooks.useState;

 class ClickCounter extends owl.Component {
  static template = "clickcounter";
-  state = useState({ value: 0 });
+  constructor() {
+    super(...arguments);
+    this.state = useState({ value: 0 });
+  }

  increment() {
    this.state.value++;
@@ -96,10 +90,11 @@ class ClickCounter extends owl.Component {
 // Application initialization
 //------------------------------------------------------------------------------
 async function start() {
-  const templates = await owl.utils.loadFile("templates.xml");
-  const qweb = new owl.QWeb({ templates });
-  owl.config.env.qweb = qweb;
-  const counter = new ClickCounter();
+  const templates = await owl.utils.loadTemplates("templates.xml");
+  const env = {
+    qweb: new owl.QWeb(templates)
+  };
+  const counter = new ClickCounter(env);
  const target = document.getElementById("main");
  await counter.mount(target);
 }
@@ -16,12 +16,11 @@
  - [Dynamic Attributes](#dynamic-attributes)
  - [Loops](#loops)
  - [Rendering Sub Templates](#rendering-sub-templates)
-  - [Translations](#translations)
  - [Debugging](#debugging)

 ## Overview

-[QWeb](https://www.odoo.com/documentation/13.0/reference/qweb.html) is the primary templating engine used by Odoo. It is based on the XML format, and used
+[QWeb](https://www.odoo.com/documentation/12.0/reference/qweb.html) is the primary templating engine used by Odoo. It is based on the XML format, and used
 mostly to generate HTML. In OWL, QWeb templates are compiled into functions that
 generate a virtual dom representation of the HTML.

@@ -34,7 +33,7 @@ To avoid element rendering, a placeholder element `<t>` is also available, which
    <span t-if="somecondition">Some string</span>
    <ul t-else="1">
        <li t-foreach="messages" t-as="message">
-            <t t-esc="message"/>
+            <t t-esc="message">
        </li>
    </ul>
 </div>
@@ -61,21 +60,20 @@ We present here a list of all standard QWeb directives:
 | `t-att`, `t-attf-*`, `t-att-*` | [Dynamic attributes](#dynamic-attributes)                    |
 | `t-call`                       | [Rendering sub templates](#rendering-sub-templates)          |
 | `t-debug`, `t-log`             | [Debugging](#debugging)                                      |
-| `t-translation`                | [Disabling the translation of a node](#translations)         |
 | `t-name`                       | [Defining a template (not really a directive)](#qweb-engine) |

 The component system in Owl requires additional directives, to express various
 needs. Here is a list of all Owl specific directives:

-| Name                     | Description                                                                         |
-| ------------------------ | ----------------------------------------------------------------------------------- |
-| `t-component`, `t-props` | [Defining a sub component](component.md#composition)                                |
-| `t-ref`                  | [Setting a reference to a dom node or a sub component](component.md#references)     |
-| `t-key`                  | [Defining a key (to help virtual dom reconciliation)](component.md#t-key-directive) |
-| `t-on-*`                 | [Event handling](component.md#event-handling)                                       |
-| `t-transition`           | [Defining an animation](animations.md#css-transitions)                              |
-| `t-slot`                 | [Rendering a slot](component.md#slots)                                              |
-| `t-model`                | [Form input bindings](component.md#form-input-bindings)                             |
+| Name                                                   | Description                                                                         |
+| ------------------------------------------------------ | ----------------------------------------------------------------------------------- |
+| `t-component`, `t-props`, `t-keepalive`, `t-asyncroot` | [Defining a sub component](component.md#composition)                                |
+| `t-ref`                                                | [Setting a reference to a dom node or a sub component](component.md#references)     |
+| `t-key`                                                | [Defining a key (to help virtual dom reconciliation)](component.md#t-key-directive) |
+| `t-on-*`                                               | [Event handling](component.md#event-handling)                                       |
+| `t-transition`                                         | [Defining an animation](animations.md#css-transitions)                              |
+| `t-slot`                                               | [Rendering a slot](component.md#slots)                                              |
+| `t-model`                                              | [Form input bindings](component.md#form-input-bindings)                             |

 ## QWeb Engine

@@ -87,16 +85,13 @@ instantiated:
 const qweb = new owl.QWeb();
 ```

-Its API is quite simple:
+It's API is quite simple:

- **`constructor(config)`**: constructor. Takes an optional configuration object
-  with an optional `templates` string to add initial
-  templates (see `addTemplates` for more information on format of the string)
-  and an optional `translateFn` translate function (see the section on
-  [translations](#translations)).
+- **`constructor(data)`**: constructor. Takes an optional string to add initial
+  templates (see `addTemplates` for more information on format of the string).

  ```js
-  const qweb = new owl.QWeb({ templates: TEMPLATES, translateFn: _t });
+  const qweb = new owl.QWeb(TEMPLATES);
  ```

 - **`addTemplate(name, xmlStr, allowDuplicate)`**: add a specific template.
@@ -105,8 +100,7 @@ Its API is quite simple:
  qweb.addTemplate("mytemplate", "<div>hello</div>");
  ```

-  If the optional `allowDuplicate` is set to `true`, then `QWeb` will simply
-  ignore templates added for a second time. Otherwise, `QWeb` will crash.
+  If the optional `allowDuplicate` is set to `true`, then `QWeb` will simply return whenever a template is added for a second time. Otherwise, `QWeb` will crash.

 - **`addTemplates(xmlStr)`**: add a list of templates (identified by `t-name`
  attribute).
@@ -121,7 +115,7 @@ Its API is quite simple:
  ```

 - **`render(name, context, extra)`**: renders a template. This returns a `vnode`,
-  which is a virtual representation of the DOM (see [vdom doc](../architecture/vdom.md)).
+  which is a virtual representation of the DOM (see [vdom doc](vdom.md)).

  ```js
  const vnode = qweb.render("App", component);
@@ -134,13 +128,13 @@ Its API is quite simple:
  const str = qweb.renderToString("someTemplate", somecontext);
  ```

- **`registerTemplate(name, template)`**: static function to register a global
+- **`registerTemplate(name, template)`**: static function to register an global
  QWeb template. This is useful for commonly used components accross the
  application, and for making a template available to an application without
  having a reference to the actual QWeb instance.

  ```js
-  QWeb.registerTemplate("mytemplate", `<div>some template</div>`);
+  QWeb.registerTemplate("mytemplate", `<div>some template`);
  ```

 - **`registerComponent(name, Component)`**: static function to register an OWL Component
@@ -159,8 +153,8 @@ Its API is quite simple:
  ```

 In some way, a `QWeb` instance is the core of an Owl application. It is the only
-mandatory element of an [environment](environment.md). As such, it
-has an extra responsibility: it can act as an event bus for internal communication
+mandatory element of an [environment](component.md#environment). As such, it
+has an extra responsability: it can act as an event bus for internal communication
 between Owl classes. This is the reason why `QWeb` actually extends [EventBus](event_bus.md).

 ## Reference
@@ -171,7 +165,7 @@ specific extensions are documented in various other parts of the documentation.

 ### White Spaces

-White spaces in a template are handled in a special way:
+White spaces in a templates are handled in a special way:

 - consecutive whitespaces are always condensed to a single whitespace
 - if a whitespace-only text node contains a linebreak, it is ignored
@@ -206,14 +200,14 @@ root nodes.
 ### Expression Evaluation

 QWeb expressions are strings that will be processed at compile time. Each variable in
-the javascript expression will be replaced with a lookup in the context (so, the
+the javascript expression will be replaced by a lookup in the context (so, the
 component). For example, `a + b.c(d)` will be converted into:

 ```js
 context["a"] + context["b"].c(context["d"]);
 ```

-It is useful to explain the various rules that apply on these expressions:
+It is useful to explain the various rules that applies on these expressions:

 1. it should be a simple expression which returns a value. It cannot be a statement.

@@ -239,14 +233,14 @@ It is useful to explain the various rules that apply on these expressions:
 3. it can use a few special operators to avoid using symbols such as `<`, `>`,
   `&` or `|`. This is useful to make sure that we still write valid XML.

-   | Word  | replaced with |
-   | ----- | ------------- |
-   | `and` | `&&`          |
-   | `or`  | `\|\|`        |
-   | `gt`  | `>`           |
-   | `gte` | `>=`          |
-   | `lt`  | `<`           |
-   | `lte` | `<=`          |
+   | Word  | will be replaced by |
+   | ----- | ------------------- |
+   | `and` | `&&`                |
+   | `or`  | `\|\|`              |
+   | `gt`  | `>`                 |
+   | `gte` | `>=`                |
+   | `lt`  | `<`                 |
+   | `lte` | `<=`                |

   So, one can write this:

@@ -291,11 +285,6 @@ rendered with the value `value` set to `<span>foo</span>` in the rendering conte
 <p><span>foo</span></p>
 ```

-Note that since the content of the expression is not known beforehand, the `t-raw`
-directive has to parse the html (and convert it to a virtual dom structure) for
-each rendering. So, it will be much slower than a regular template. It is
-therefore advised to limit the use of `t-raw` whenever possible.
-
 ### Setting Variables

 QWeb allows creating variables from within the template, to memoize a computation (to use it multiple times), give a piece of data a clearer name, ...
@@ -395,25 +384,14 @@ If an expression evaluates to a falsy value, it will not be set at all:
 <div t-att-foo="false"/>  <!-- result: <div></div> -->
 ```

-It is sometimes convenient to format an attribute with string interpolation. In
-that case, the `t-attf-` directive can be used. It is useful when we need to mix
-literal and dynamic elements, such as css classes.
+There is another way to format a string attribute: the `t-attf-` directive. With
+it, you get string interpolation:

 ```xml
 <div t-attf-foo="a {{value1}} is {{value2}} of {{value3}} ]"/>
 <!-- result if values are set to 1,2 and 3: <div foo="a 0 is 1 of 2 ]"></div> -->
 ```

-If we need completely dynamic attribute names, then there is an additional
-directive: `t-att`, which takes either an object (with keys mapping to their
-values) or a pair `[key, value]`. For example:
-
-```xml
-<div t-att="{'a': 1, 'b': 2}"/> <!-- result: <div a="1" b="2"></div> -->
-
-<div t-att="['a', 'b']"/> <!-- <div a="b"></div> -->
-```
-
 ### Loops

 QWeb has an iteration directive `t-foreach` which take an expression returning the
@@ -448,7 +426,7 @@ is equivalent to the previous example.
 or an object (the current item will be the current key).

 In addition to the name passed via t-as, `t-foreach` provides a few other
-variables for various data points (note: `$as` will be replaced with the name
+variables for various data points (note: `$as` will be replaced by the name
 passed to `t-as`):

 - `$as_value`: the current iteration value, identical to `$as` for lists and
@@ -466,33 +444,19 @@ the context of the `t-foreach`, the value is copied at the end of the foreach
 into the global context.

 ```xml
-<t t-set="existing_variable" t-value="false"/>
+<t t-set="existing_variable" t-value="False"/>
 <!-- existing_variable now False -->

 <p t-foreach="Array(3)" t-as="i">
-    <t t-set="existing_variable" t-value="true"/>
-    <t t-set="new_variable" t-value="true"/>
-    <!-- existing_variable and new_variable now true -->
+    <t t-set="existing_variable" t-value="True"/>
+    <t t-set="new_variable" t-value="True"/>
+    <!-- existing_variable and new_variable now True -->
 </p>

-<!-- existing_variable always true -->
+<!-- existing_variable always True -->
 <!-- new_variable undefined -->
 ```

-Owl QWeb is used as the template engine for components. Components are frequently
-updated, and reuse as much of the previous DOM as possible. Loops offer a specific
-problem for this usecase: how does the template engine know if two rows have
-been swapped, or if the content of these rows was changed? To help Owl with that,
-there is an additional directive: [`t-key`](component.md#t-key-directive).
-
-```xml
-<p t-foreach="state.things" t-as="thing" t-key="thing.id">
-    <t t-esc="thing.content"/>
-</p>
-```
-
-If there is no `t-key` directive, Owl will use the index as a default key.
-
 ### Rendering Sub Templates

 QWeb templates can be used for top level rendering, but they can also be used
@@ -541,53 +505,6 @@ will result in :
 </div>
 ```

-### Translations
-
-If properly setup, Owl QWeb engine can translate all rendered templates. To do
-so, it needs a translate function, which takes a string and returns a string.
-
-For example:
-
-```js
-const translations = {
-  hello: "bonjour",
-  yes: "oui",
-  no: "non"
-};
-const translateFn = str => translations[str] || str;
-
-const qweb = new QWeb({ translateFn });
-```
-
-Once setup, all rendered templates will be translated using `translateFn`:
-
- each text node will be replaced with its translation,
- each of the following attribute values will be translated as well: `title`,
-  `placeholder`, `label` and `alt`,
- translating text nodes can be disabled with the special attribute `t-translation`,
-  if its value is `off`.
-
-So, with the above `translateFn`, the following templates:
-
-```xml
-<div>hello</div>
-<div t-translation="off">hello</div>
-<div>Are you sure?</div>
-<input placeholder="hello" other="yes"/>
-```
-
-will be rendered as:
-
-```xml
-<div>bonjour</div>
-<div>hello</div>
-<div>Are you sure?</div>
-<input placeholder="bonjour" other="yes"/>
-```
-
-Note that the translation is done during the compilation of the template, not
-when it is rendered.
-
 ### Debugging

 The javascript QWeb implementation provides two useful debugging directives:
@@ -609,4 +526,4 @@ will stop execution if the browser dev tools are open.
 <t t-log="foo"/>
 ```

-will print 42 to the console.
+will print 42 to the console
@@ -8,81 +8,58 @@ build applications. Here is a complete representation of its content:
 ```
 owl
    Component
-    Context
    QWeb
-    Store
    useState
-    config
-        mode
-        env
    core
        EventBus
        Observer
    hooks
-        onWillStart
        onMounted
-        onWillUpdateProps
+        onWillUnmount
        onWillPatch
        onPatched
-        onWillUnmount
-        useContext
        useState
        useRef
        useSubEnv
-        useStore
-        useDispatch
-        useGetters
-    misc
-        AsyncRoot
    router
        Link
        RouteComponent
        Router
+    store
+        Store
+        ConnectedComponent
    tags
        xml
    utils
        debounce
        escape
        loadJS
-        loadFile
-        shallowEqual
+        loadTemplates
        whenReady
 ```

 Note that for convenience, the `useState` hook is also exported at the root of the `owl` object.

-## Learning Resources
-
- [Quick Start: create an (almost) empty Owl application](learning/quick_start.md)
- [Environment: what it is and what it should contain](learning/environment.md)
-
 ## Reference

- [Animations](reference/animations.md)
- [Component](reference/component.md)
- [Configuration](reference/config.md)
- [Context](reference/context.md)
- [Environment](reference/environment.md)
- [Event Bus](reference/event_bus.md)
- [Hooks](reference/hooks.md)
- [Misc](reference/misc.md)
- [Observer](reference/observer.md)
- [QWeb](reference/qweb.md)
- [Router](reference/router.md)
- [Store](reference/store.md)
- [Tags](reference/tags.md)
- [Utils](reference/utils.md)
+- [Animations](animations.md)
+- [Component](component.md)
+- [Event Bus](event_bus.md)
+- [Hooks](hooks.md)
+- [Observer](observer.md)
+- [QWeb](qweb.md)
+- [Router](router.md)
+- [Store](store.md)
+- [Tags](tags.md)
+- [Utils](utils.md)
+- [Virtual DOM](vdom.md)
+
+## Learning Resources
+
+- [Quick Start](quick_start.md)

 ## Miscellaneous

 - [Comparison with React/Vue](comparison.md)
 - [Tooling](tooling.md)
 - [Templates to start Owl applications (external link)](https://github.com/ged-odoo/owl-templates)
-
-## Architecture
-
-This section explains in more detail the inner workings of Owl. It is more
-useful for people working on Owl code.
-
- [Virtual DOM](architecture/vdom.md)
- [Rendering](architecture/rendering.md)
@@ -1,56 +0,0 @@
-# 🦉 Config 🦉
-
-The Owl framework is designed to work in many situations.  However, it is
-sometimes necessary to customize some behaviour.  This is done by using the
-global `config` object. It currently has two keys:
-
- [`mode`](#mode),
- [`env`](#env).
-
-## Mode
-
-By default, Owl is in _production_ mode, this means that it will try to do its
-job fast, and skip some expensive operations. However, it is sometimes necessary
-to have better information on what is going on, this is the purpose
-of the `dev` mode.
-
-Owl has a mode flag, in `owl.config.mode`. Its default value is `prod`, but
-it can be set to `dev`:
-
-```js
-owl.config.mode = "dev";
-```
-
-Note that templates compiled with the `prod` settings will not be recompiled.
-So, changing this setting is best done at startup.
-
-An important job done by the `dev` mode is to validate props for each component
-creation and update. Also, extra props will cause an error.
-
-## Env
-
-An Owl application needs an [environment](environment.md) to be executed. The
-environment has an important key: the [QWeb](qweb.md) instance, which will render
-all templates.
-
-Whenever a root component is mounted, Owl will take the environment from
-`owl.config.env` and use it to setup the component (and its children).
-
- if no environment was setup, an empty environment will be generated,
- if an environment exists, but does not have a QWeb key, a new QWeb instance
-  will then be added to the environment.
-
-The correct way to customize an environment is to simply modify `owl.config.env`
-before the first component is created:
-
-```js
-owl.config.env = {
-    _t: myTranslateFunction,
-    user: {...},
-    services: {
-        ...
-    },
-};
-const app = new App();
-app.mount(document.body);
-```
@@ -1,105 +0,0 @@
-# 🦉 Context 🦉
-
-## Content
-
- [Overview](#overview)
- [Example](#example)
- [Reference](#reference)
-  - [`Context`](#context)
-  - [`useContext`](#usecontext)
-
-## Overview
-
-The `Context` object provides a way to share data between an arbitrary number
-of components. Usually, data is passed from a parent to its children component,
-but when we have to deal with some mostly global information, this can be
-annoying, since each component will need to pass the information to each children,
-even though some or most of them will not use the information.
-
-With a `Context` object, each component can subscribe (with the `useContext` hook)
-to its state, and will be updated whenever the context state is updated.
-
-## Example
-
-Assume that we have an application with various components which needs to render
-differently depending on the size of the device. Here is how we could proceed
-to make sure that the information is properly shared. First, let us create a
-context, and add it to the environment:
-
-```js
-const deviceContext = new Context({ isMobile: true });
-owl.config.env.deviceContext = deviceContext;
-```
-
-If we want to make it completely responsive, we need to update its value whenever
-the size of the screen is updated:
-
-```js
-const isMobile = () => window.innerWidth <= 768;
-window.addEventListener(
-  "resize",
-  owl.utils.debounce(() => {
-    const state = deviceContext.state;
-    if (state.isMobile !== isMobile()) {
-      state.isMobile = !state.isMobile;
-    }
-  }, 15)
-);
-```
-
-Then, each component that want can subscribe and render differently depending on the
-fact that we are in a mobile or desktop mode.
-
-```js
-class SomeComponent extends Component {
-  static template = xml`
-        <div>
-          <t t-if=device.isMobile>
-             some simplified user interface
-          </t>
-          <t t-else="1">
-             some more sopthisticated user interface
-          </t>
-    `;
-  device = useContext(this.env.deviceContext);
-}
-```
-
-## Reference
-
-### `Context`
-
-A `Context` object should be created with a state object:
-
-```js
-const someContext = new Context({ some: "key" });
-```
-
-Its state is now available in the `state` key:
-
-```js
-someContext.state.some = "other key";
-```
-
-This is the way some global code (such as the responsive code above) should
-read and update the context state. However, components should not ever read the
-context state directly from the context, they should instead use the `useContext`
-hook to properly register themselves to state changes.
-
-Note that the `Context` hook is different from the React version. For example,
-there is no concept of provider/consumer. So, the `Context` feature does not
-by itself allow the use of a different context state depending on the component
-place in the component tree. However, this functionality can be obtained, if
-necessary, with the use of sub environment.
-
-### `useContext`
-
-The `useContext` hook is the normal way for a component to register themselve
-to context state changes. The `useContext` method returns the context state:
-
-```js
-device = useContext(this.env.deviceContext);
-```
-
-It is a simple observed state (with an owl `Observer`), which contains the shared
-information.
@@ -1,18 +0,0 @@
-# 🦉 Environment 🦉
-
-An environment is an object which contains a [`QWeb` instance](qweb.md). Whenever a root component is created, it is assigned an environment. This environment
-is then automatically given to each sub component (and accessible in the `this.env` property).
-
-```
-    Root
-    /  \
-   A    B
-```
-
-This way, all components share the same `QWeb` instance.
-
-Note: some additional information can be found here:
-
- [What should go into an environment?](../learning/environment.md)
- [Customizing an environment](config.md#env)
-
@@ -1,23 +0,0 @@
-# 🦉 Miscellaneous 🦉
-
-## `AsyncRoot`
-
-When this component is used, a new rendering sub tree is created, such that the
-rendering of that component (and its children) is not tied to the rendering of
-the rest of the interface. It can be used on an asynchronous component, to
-prevent it from delaying the rendering of the whole interface, or on a
-synchronous one, such that its rendering isn't delayed by other (asynchronous)
-components. Note that this directive has no effect on the first rendering, but
-only on subsequent ones (triggered by state or props changes).
-
-```xml
-<div t-name="ParentComponent">
-  <SyncChild />
-  <AsyncRoot>
-     <AsyncChild/>
-  </AsyncRoot>
-</div>
-```
-
-The `AsyncRoot` assumes that there is exactly one root node inside it. It can
-be a dom node or a component.
@@ -1,52 +0,0 @@
-# 🦉 Observer 🦉
-
-Owl needs to be able to react to state changes. For example, whenever the state
-of a component is changed, Owl needs to rerender it. To help with that, there is
-an Observer class. Its job is to observe the state of an object (or array), and
-to react to any change. The observer is implemented with the native `Proxy`
-object. Note that this means that it will not work on older browsers.
-
-Note that the `Observer` is used by the `useState` and `useContext` hooks. This
-is the way most Owl applications will create observers. For the majority of
-use cases, there is no need to directly instantiate an observer.
-
-## Example
-
-For example, this code will display `update` in the console:
-
-```javascript
-const observer = new owl.Observer();
-observer.notifyCB = () => console.log("update");
-const obj = observer.observe({ a: { b: 1 } });
-
-obj.a.b = 2;
-```
-
-This example shows that an observer can observe nested properties.
-
-## Reference
-
-**observe** An observer can observe multiple values with the `observe` method.
-This method takes an object or an array as its argument and will return a proxy
-(which is mapped to the initial object/array). With this proxy, the observer
-can detect whenever any internal value is changed.
-
-**Registering a callback** Whenever an observer sees a state change, it will
-call its `notifyCB` method. No additional information is given to the callback.
-
-**deepRevNumber** Each observed value has an internal revision number, which
-is incremented every time the value is observed. Sometimes, it can be useful
-to obtain that number:
-
-```js
-const observer = new owl.Observer();
-const obj = observer.observe({ a: { b: 1 } });
-
-observer.deepRevNumber(obj.a); // 1
-obj.a.b = 2;
-
-observer.deepRevNumber(obj.a); // 2
-```
-
-The `deepRevNumber` can also return 0, which indicates that the value is not
-observed.
@@ -1,148 +0,0 @@
-# 🦉 Utils 🦉
-
-Owl export a few useful utility functions, to help with common issues. Those
-functions are all available in the `owl.utils` namespace.
-
-## Content
-
- [`whenReady`](#whenready): executing code when DOM is ready
- [`loadJS`](#loadjs): loading script files
- [`loadFile`](#loadfile): loading a file (useful for templates)
- [`escape`](#escape): sanitizing strings
- [`debounce`](#debounce): limiting rate of function calls
- [`shallowEqual`](#shallowequal): shallow object comparison
-
-## `whenReady`
-
-The function `whenReady` returns a `Promise` resolved when the DOM is ready (if
-not ready yet, resolved directly otherwise). If called with a callback as
-argument, it executes it as soon as the DOM ready (or directly).
-
-```js
-Promise.all([loadFile("templates.xml"), owl.utils.whenReady()]).then(function([templates]) {
-  const qweb = new owl.QWeb({ templates });
-  const app = new App({ qweb });
-  app.mount(document.body);
-});
-```
-
-or alternatively:
-
-```js
-owl.utils.whenReady(function() {
-  const qweb = new owl.QWeb();
-  const app = new App({ qweb });
-  app.mount(document.body);
-});
-```
-
-## `loadJS`
-
-`loadJS` takes a url (string) for a javascript resource, and loads it (by adding
-a script tag in the document head). It returns a promise, so the caller can
-properly reacts when it is ready. Also, it is smart: it maintains a list of urls
-previously loaded (or currently being loaded), and prevent doing twice the work.
-
-For example, it is useful for lazy loading external libraries:
-
-```js
-class MyComponent extends owl.Component {
-  willStart() {
-    return owl.utils.loadJS("/static/libs/someLib.js");
-  }
-}
-```
-
-## `loadFile`
-
-`loadFile` is a helper function to fetch a file. It simply
-performs a `GET` request and returns the resulting string in a promise. The
-initial usecase for this function is to load a template file. For example:
-
-```js
-async function makeEnv() {
-  const templates = await owl.utils.loadFile("templates.xml");
-  const qweb = new owl.QWeb({ templates });
-  return { qweb };
-}
-```
-
-Note that unlike `loadJS`, this function returns the content of the file as a
-string. It does not add a `script` tag or any other side effect.
-
-## `escape`
-
-Sometimes, we need to display dynamic data (for example user-generated data) in
-the user interface. If this is done by a `QWeb` template, it is not an issue:
-
-```xml
-    <div><t t-esc="user.data"/></div>
-```
-
-The `QWeb` engine will create a `div` node and add the content of the `user.data`
-string as a text node, so the web browser will not parse it as html. However,
-it may be a problem if this is done with some javascript code like this:
-
-```js
-class BadComponent extends Component {
-  // some template with a ref to a div
-  // some code ...
-
-  mounted() {
-    this.divRef.el.innerHTML = this.state.value;
-  }
-}
-```
-
-In this case, the content of the `div` will be parsed as html, which may inject
-unwanted behaviour. To fix this, the `escape` function will simply transform a
-string into an escaped version of the same string, which will be properly displayed
-by the browser, but which will not be parsed as html (for example, `"<ok>"` is
-escaped to the string: `"&lt;ok&gt;"`). So, the bad example above can be fixed
-with the following change:
-
-```js
-this.divRef.el.innerHTML = owl.utils.escape(this.state.value);
-```
-
-## `debounce`
-
-The `debounce` function is useful when we want to limit the number of times some
-function/action is perfomed. For example, this may be useful to prevent issue
-with people double clicking on a button.
-
-It takes three arguments:
-
- `func` (function): this is the function that will be rate limited
- `wait` (number): this is the number of milliseconds that we want to use to
-  rate limit the function `func`
- `immediate` (optional, boolean, default=false): if `immediate` is true, the
-  function will be triggered immediately (leading edge of the interval). If false,
-  the function will be triggered at the end (trailing edge).
-
-It returns a function. For example:
-
-```js
-const debounce = owl.utils.debounce;
-window.addEventListener("mousemove", debounce(doSomething, 100));
-```
-
-As this example shows, it is usualy useful for event handlers which are triggered
-very quickly, such as `scroll` or `mousemove` events.
-
-## `shallowEqual`
-
-This function checks if two objects have the same values assigned to each keys:
-
-```js
-shallowEqual({ a: 1, b: 2 }, { a: 1, b: 2 }); // true
-shallowEqual({ a: 1, b: 2 }, { a: 1, b: 3 }); // false
-```
-
-However, for performance reasons, it assumes that the two objects have the same
-keys. If we are in a situation where this is not guaranteed, the following code
-will work:
-
-```js
-const completeShallowEqual = (a, b) => shallowEqual(a, b) && shallowEqual(b, a);
-```
@@ -67,9 +67,6 @@ function makeEnvironment() {
    await env.router.start();
    return env;
 }
-
-owl.config.env = makeEnvironment();
-// create root component here
 ```

 Notice that the router needs to be started. This is an asynchronous operation
@@ -100,13 +97,6 @@ The `Router` constructor takes three arguments:
 - an optional object (with the only key `mode` which can be `history` (default
  value) or `hash`).

-`history` will use the browser [History API](https://developer.mozilla.org/en-US/docs/Web/API/History_API) as the mechanism to manage URL.\
-Example: `https://yourdomain.tld/my_custom_route`.\
-For this mechanism to work, you need a way to configure your web server accordingly.
-
-`hash` will manipulate the hash of the URL.\
-Example: `https://yourdomain.tld/index.html#/my_custom_route`.
-
 ```js
 const ROUTES = [...];
 const router = new owl.router.Router(env, ROUTES, {mode: 'history'});
@@ -9,9 +9,6 @@
  - [Actions](#actions)
  - [Getters](#getters)
  - [Connecting a Component](#connecting-a-component)
-  - [`useStore`](#usestore)
-  - [`useDispatch`](#usedispatch)
-  - [`useGetters`](#usegetters)
  - [Semantics](#semantics)
  - [Good Practices](#good-practices)

@@ -19,14 +16,13 @@

 Managing the state in an application is not an easy task. In some cases, the
 state of an application can be part of the component tree, in a natural way.
-However, there are situations where some parts of the state need to be displayed
+However, there are situations where some part of the state need to be displayed
 in various parts of the user interface, and then, it is not obvious which
 component should own which part of the state.

 Owl's solution to this issue is a centralized store. It is a class that owns
-some (or all) state, and lets the developer update it in a structured way, with
-`actions`. Owl components can then connect to the store, and will be updated if
-necessary.
+some state, and let the developer update it in a structured way, with `actions`.
+Owl components can then connect to the store, and will be updated if necessary.

 Note: Owl store is inspired by React Redux and VueX.

@@ -51,7 +47,7 @@ const state = {
 };

 const store = new owl.Store({ state, actions });
-store.on("update", null, () => console.log(store.state));
+store.on("update", () => console.log(store.state));

 // updating the state
 store.dispatch("addTodo", "fix all bugs");
@@ -114,15 +110,6 @@ const actions = {
 };
 ```

-The first argument to an action method is an object with four keys:
-
- `state`: the current state of the store content,
- `dispatch`: a function that can be used to dispatch other actions,
- `getters`: an object containing all getters defined in the store,
- `env`: the current environment. This is useful sometimes, in particular if
-  an action needs to apply some side effects (such as performing an rpc), and
-  the `rpc` method is located in the environment.
-
 Actions are called with the `dispatch` method on the store, and can receive an
 arbitrary number of arguments.

@@ -135,7 +122,7 @@ call.

 Also, it is important to be aware that we need to be careful with asynchronous
 logic. Each state change will potentially trigger a rerendering, so we need to
-make sure that we do not have a partially corrupted state. Here is an example that
+make sure that we do not have a partial corrupted state. Here is an example that
 is likely not a good idea:

 ```javascript
@@ -188,7 +175,7 @@ transform the data contained in the store.
 const getters = {
  getPost({ state }, id) {
    const post = state.posts.find(p => p.id === id);
-    const author = state.authors.find(a => a.id === post.id);
+    const author = state.authors.find(a => (a.id = post.id));
    return {
      id,
      author,
@@ -203,124 +190,100 @@ const post = store.getters.getPost(id);

 Getters take _at most_ one argument.

-Note that getters are not cached.
+Note that getters are cached if they don't take any argument, or their argument
+is a string or a number.

 ### Connecting a Component

-At some point, we need a way to interact with the store from a component. This
-can be done with the help of the three store hooks:
-
- [`useStore`](#usestore) to subscribe a component to some part of the store state,
- [`useDispatch`](#usedispatch) to get a reference to a dispatch function,
- [`useGetters`](#usegetters) to get a reference to the getters defined in the store.
-
-Assume we have this store:
+At some point, we need a way to access the state in the store from a component.
+By default, an Owl `Component` is not connected to any store. To do that, we
+need to create a component inheriting from `OwlComponent`:

 ```javascript
 const actions = {
  increment({ state }, val) {
-    state.counter.value += val;
+    state.counter += val;
  }
 };

 const state = {
-  counter: { value: 0 }
+  counter: 0
 };
 const store = new owl.Store({ state, actions });
-```

-A counter component can then select this value and dispatch an action like this:
-
-```js
-class Counter extends Component {
-  counter = useStore(state => state.counter);
-  dispatch = useDispatch();
+class Counter extends owl.ConnectedComponent {
+  static mapStoreToProps(state) {
+    return {
+      value: state.counter
+    };
+  }
+  increment() {
+    this.env.store.dispatch("increment");
+  }
 }

 const counter = new Counter({ store, qweb });
 ```

 ```xml
-<button t-name="Counter" t-on-click="dispatch('increment')">
-  Click Me! [<t t-esc="counter.value"/>]
+<button t-name="Counter" t-on-click="increment">
+  Click Me! [<t t-esc="props.value"/>]
 </button>
 ```

-### `useStore`
+The `ConnectedComponent` class can be configured with the following fields:

-The `useStore` hook is used to select some part of the store state. It accepts
-two arguments:
+- `mapStoreToProps`: a function that extracts the `props` of the Component
+  from the `state` of the `Store` and returns them as a dict.
+- `getStore`: a function that takes the `env` in arguments and returns an
+  instance of `Store` to connect to (if not given, connects to `env.store`)
+- `hashFunction`: the function to use to detect changes in the state (if not
+  given, generates a function that uses revision numbers, incremented at
+  each state change)
+- `deep` (boolean): [only useful if no hashFunction is given] if `false`, only watch
+  for top level state changes (`true` by default)

- a selector function, which takes the store state as first argument (and the
-  component props as second argument) and returns
-  an object or an array (which will be then observed),
- optionally, an object with a `store` key (if we want to override the default
-  store) and an equality function (if we want to specialize the comparison).
+Note that the class `ConnectedComponent` has a `dispatch` method. This means
+that the previous example could be simplified like this:

-If the `useStore` callback selects a sub part of the store state, the component
-will only be rerendered whenever this part of the state changes. Otherwise, it
-will perform a strict equality check and will update the component every time this
-check fails.
-
-Also, it may not be obvious, but it is crucial to remember that the selector
-function should return an object or an array. The reason is that it needs to be
-observed, otherwise the component would not be able to react to changes.
-
-### `useDispatch`
-
-The `useDispatch` hook is useful when a component needs to be able to dispatch
-actions. It takes an optional argument, which is a store. If not given, it will
-use the store in the environment.
-
-Note that a component does not need to be connected in any other way to the store.
-For example:
-
-```js
-class DoSomethingButton extends Component {
-  static template = xml`<button t-on-click="dispatch('something')">Click</button>`;
-  dispatch = useDispatch();
+```javascript
+class Counter extends owl.ConnectedComponent {
+  static mapStoreToProps(state) {
+    return {
+      value: state.counter
+    };
+  }
 }
 ```

-### `useGetters`
-
-The `useGetters` hook is useful when a component needs to be able to use the
-getters defined in a store. It takes an optional argument, which is a store. If
-not given, it will use the store in the environment.
-
-Note that a component does not need to be connected in any other way to the store.
-For example:
-
-```js
-class InfoButton extends Component {
-  static template = xml`<span><t t-esc="getters.somevalue()"></span>`;
-  getters = useGetters();
-}
+```xml
+<button t-name="Counter" t-on-click="dispatch('increment')">
+  Click Me! [<t t-esc="props.value"/>]
+</button>
 ```

 ### Semantics

-The `Store` class and the `useStore` hook try to be smart and to optimize as much
+The `Store` and the `ConnectedComponent` try to be smart and to optimize as much
 as possible the rendering and update process. What is important to know is:

 - components are always updated in the order of their creation (so, parent
-  before children),
- they are updated only if they are in the DOM,
+  before children)
+- they are updated only if they are in the DOM
 - if a parent is asynchronous, the system will wait for it to complete its
-  update before updating other components,
+  update before updating other components.
 - in general, updates are not coordinated. This is not a problem for synchronous
  components, but if there are many asynchronous components, this could lead to
-  a situation where some part of the UI is updated and some other part of the UI is
+  a situation where some part of the UI is updated and other parts of the UI is
  not updated.

 ### Good Practices

 - avoid asynchronous components as much as possible. Asynchronous components
-  lead to situations where parts of the UI is not updated immediately,
+  lead to situations where parts of the UI is not updated immediately.
 - do not be afraid to connect many components, parent or children if needed. For
-  example, a `MessageList` component could get a list of ids in its `useStore`
-  call and a `Message` component could get the data of its own
-  message,
- since the `useStore` function is called for each connected component,
+  example, a `MessageList` component could get a list of ids in its `mapStoreToProps` and a `Message` component could get the data of its own
+  message
+- since the `mapStoreToProps` function is called for each connected component,
  for each state update, it is important to make sure that these functions are
  as fast as possible.
@@ -1,15 +1,8 @@
 # 🦉 Tags 🦉

-## Content
-
- [Overview](#overview)
- [`xml` tag](#xml-tag)
-
-## Overview
-
-Tags are very small helpers to make it easy to write inline templates. There is
+Tags are very small helper to make it easy to write inline templates. There is
 only one currently available tag: `xml`, but we plan to add other tags later,
-such as a `css` tag, which will be used to write [single file components](../tooling.md#single-file-component).
+such as a `css` tag, which will be used to write single file components.

 ## XML tag

@@ -38,8 +31,8 @@ With tags, this process is slightly simplified. The name is uniquely generated,
 and the template is automatically registered:

 ```js
-const { Component } = owl;
-const { xml } = owl.tags;
+import { Component } from 'owl'
+import { xml } from 'owl/tags'

 class MyComponent extends Component {
    static template = xml`
@@ -3,6 +3,7 @@
 ## Content

 - [Overview](#overview)
+- [Development Mode](#development-mode)
 - [Playground](#playground)
 - [Benchmarks](#benchmarks)
 - [Single File Component](#single-file-component)
@@ -20,6 +21,26 @@ by using a static http server. A simple python
 server is available in `server.py`. There is also a npm script to start it:
 `npm run tools` (and its version with a watcher: `npm run tools:watch`).

+## Development Mode
+
+By default, Owl is in _production_ mode, this means that it will try to do its
+job fast, and skip some expensive operations. However, in some cases, it is
+convenient to have better information on what is going on, this is the purpose
+of the dev mode.
+
+Owl has a mode flag, in `owl.__info__.mode`. Its default value is `prod`, but
+it can be set to `dev`:
+
+```js
+owl.__info__.mode = "dev";
+```
+
+Note that templates compiled with the `prod` settings will not be recompiled.
+So, changing this setting is best done at startup.
+
+An important job done by the `dev` mode is to validate props for each component
+creation and update. Also, extra props will cause an error.
+
 ## Playground

 The playground is an important application designed to help learning and
@@ -39,21 +60,12 @@ useful to compare various performance metrics on some tasks.

 ## Single File Component

-It is very useful to group code by feature instead of by type of file. It makes
-it easier to scale application to larger size.
-
-To do so, Owl currently has a small helper that makes it easy to define a
-template inside a javascript (or typescript) file: the [`xml`](reference/tags.md#xml-tag)
-helper. With this, a template is automatically registered to [QWeb](reference/qweb.md).
-
-This means that the template and the javascript code can be defined in the same
-file. It is not currently possible to add css to the same file, but Owl may
-get a `css` tag helper later.
+If you want to have `xml` syntax highlighting while using the `xml` helper which
+helps you define inline templates, there is a VS Code addon `Comment tagged template`
+which, if installed, does exactly that. To enable it, you need to add a comment,
+like this:

 ```js
-const { Component } = owl;
-const { xml } = owl.tags;
-
 // -----------------------------------------------------------------------------
 // TEMPLATE
 // -----------------------------------------------------------------------------
@@ -73,8 +85,3 @@ class MyComponent extends Component {
  // rest of component...
 }
 ```
-
-Note that the above example has an inline xml comment, just after the `xml` call.
-This is useful for some editor plugins, such as the VS Code addon
-`Comment tagged template`, which, if installed, add syntax highlighting to the
-content of the template string.
@@ -0,0 +1,63 @@
+# 🦉 Utils 🦉
+
+Owl export a few useful utility functions, to help with common issues. Those
+functions are all available in the `owl.utils` namespace.
+
+## Content
+
+- [`whenReady`](#whenready): executing code when DOM is ready
+- [`loadJS`](#loadjs): loading script files
+- [`loadTemplates`](#loadtemplates): loading xml files
+- [`escape`](#escape): sanitizing strings
+- [`debounce`](#debounce): limiting rate of function calls
+
+## `whenReady`
+
+The function `whenReady` returns a `Promise` resolved when the DOM is ready (if
+not ready yet, resolved directly otherwise). If called with a callback as
+argument, it executes it as soon as the DOM ready (or directly).
+
+```js
+Promise.all([loadTemplates(), owl.utils.whenReady()]).then(function([templates]) {
+  const qweb = new owl.QWeb(templates);
+  const app = new App({ qweb });
+  app.mount(document.body);
+});
+```
+
+```js
+owl.utils.whenReady(function() {
+  const qweb = new owl.QWeb();
+  const app = new App({ qweb });
+  app.mount(document.body);
+});
+```
+
+## `loadJS`
+
+`loadJS` takes a url (string) for a javascript resource, and loads it. It returns
+a promise, so the caller can properly react when it is ready. Also, it is smart:
+it maintains a list of urls previously loaded (or currently being loaded), and
+prevent doing twice the work.
+
+```js
+class MyComponent extends owl.Component {
+  willStart() {
+    return owl.utils.loadJS("/static/libs/someLib.js");
+  }
+}
+```
+
+## `loadTemplates`
+
+```js
+async function makeEnv() {
+  const templates = await owl.utils.loadTemplates("templates.xml");
+  const qweb = new owl.QWeb(templates);
+  return { qweb };
+}
+```
+
+## `escape`
+
+## `debounce`
@@ -1,11 +1,8 @@
 {
  "name": "owl-framework",
-  "version": "1.0.0-alpha",
+  "version": "0.22.0",
  "description": "Odoo Web Library (OWL)",
  "main": "src/index.ts",
-  "engines": {
-    "node": ">=10.15.3"
-  },
  "scripts": {
    "build:js": "tsc --target esnext --module es6 --outDir dist/owl",
    "build:bundle": "rollup -c",
@@ -17,8 +14,7 @@
    "tools:serve": "python3 tools/server.py || python tools/server.py",
    "tools": "npm run build && npm run tools:serve",
    "pretools:watch": "npm run build",
-    "tools:watch": "npm-run-all  --parallel tools:serve \"build:* -- --watch\"",
-    "prettier": "prettier {src/*.ts,src/**/*.ts,tests/*.ts,tests/**/*.ts,doc/*.md,doc/**/*.md} --write"
+    "tools:watch": "npm-run-all  --parallel tools:serve \"build:* -- --watch\""
  },
  "repository": {
    "type": "git",
@@ -44,7 +40,7 @@
    "sass": "^1.16.1",
    "source-map-support": "^0.5.10",
    "ts-jest": "^23.10.5",
-    "typescript": "^3.6.4",
+    "typescript": "^3.2.2",
    "uglify-es": "^3.3.9"
  },
  "jest": {
@@ -1,48 +0,0 @@
-# 🦉 OWL Roadmap 🦉
-
- Current version: 1.0.0-alpha
- Status: mostly stable
-
-This roadmap is only an attempt at predicting Owl's future.  Everything may
-change!
-
-
-### November 2019
-
-Owl will be used in various Odoo projects. We plan to:
-
- fix any issues encountered
- maybe cleanup slightly the router API
- improve the documentation
- improve error handling, add more helpful error messages
-
-### December 2019
-
-If all goes well, Owl will be upgraded to beta status. From then, no API change,
-even small, is expected.
-
-### End of 2019
-
-Release v1.0
-
- API should be stable,
- we will use semantic versioning,
- we will maintain a changelog and an upgrade guide.
-
-### 1.x
-
- add chrome and firefox devtools,
- add support for single file components,
- fix every bugs,
- improve documentation,
- small backward compatible improvements.
-
-### 2.x (2021? 2022?)
-
-Maybe:
-
- reimplement vdom to use *block* system, like Vue 3,
- refactor `QWeb` to use an intermediate representation (some kind of AST) to
-  allow additional optimisations.
-
-
@@ -1,11 +1,8 @@
 import { Observer } from "../core/observer";
 import { CompiledTemplate, QWeb } from "../qweb/index";
 import { h, patch, VNode } from "../vdom/index";
-import { config } from "../config";
 import "./directive";
-import { Fiber } from "./fiber";
 import "./props_validation";
-import { scheduler } from "./scheduler";

 /**
 * Owl Component System
@@ -14,6 +11,7 @@ import { scheduler } from "./scheduler";
 * contains:
 *
 * - the Env interface (generic type for the environment)
+ * - the Fiber interface (owl metadata attached to a rendering)
 * - the Internal interface (the owl specific metadata attached to a component)
 * - the Component class
 */
@@ -36,6 +34,27 @@ export interface Env {
  [key: string]: any;
 }

+/**
+ * Fibers are small abstractions designed to contain all the internal state
+ * associated to a "rendering work unit", relative to a specific component.
+ *
+ * A rendering will cause the creation of a fiber for each impacted components.
+ */
+export interface Fiber<Props> {
+  force: boolean;
+  rootFiber: Fiber<any> | null;
+  isCancelled: boolean;
+  scope: any;
+  vars: any;
+  patchQueue: Fiber<any>[];
+  component: Component<any, any>;
+  vnode: VNode | null;
+  props: Props;
+  promise: Promise<VNode> | null;
+  //   handlers?: any;
+  //   mountedHandlers?: any;
+}
+
 /**
 * This is mostly an internal detail of implementation. The Meta interface is
 * useful to typecheck and describe the internal keys used by Owl to manage the
@@ -45,9 +64,7 @@ interface Internal<T extends Env, Props> {
  // each component has a unique id, useful mostly to handle parent/child
  // relationships
  readonly id: number;
-  depth: number;
  vnode: VNode | null;
-  pvnode: VNode | null;
  isMounted: boolean;
  isDestroyed: boolean;

@@ -60,17 +77,15 @@ interface Internal<T extends Env, Props> {
  // the component instance back whenever the template is rerendered.
  cmap: { [key: number]: number };

-  currentFiber: Fiber | null;
+  currentFiber: Fiber<Props> | null;

  boundHandlers: { [key: number]: any };
  observer: Observer | null;
-  renderFn: CompiledTemplate;
+  render: CompiledTemplate | null;
  mountedCB: Function | null;
  willUnmountCB: Function | null;
  willPatchCB: Function | null;
  patchedCB: Function | null;
-  willStartCB: Function | null;
-  willUpdatePropsCB: Function | null;
  classObj: { [key: string]: boolean } | null;
  refs: { [key: string]: Component<T, any> | HTMLElement | undefined } | null;
 }
@@ -84,7 +99,7 @@ export class Component<T extends Env, Props extends {}> {
  readonly __owl__: Internal<Env, Props>;
  static template?: string | null = null;
  static _template?: string | null = null;
-  static current: Component<any, any> | null = null;
+  static _current?: any | null = null;
  static components = {};
  static props?: any;
  static defaultProps?: any;
@@ -107,32 +122,46 @@ export class Component<T extends Env, Props extends {}> {
  /**
   * Creates an instance of Component.
   *
+   * The root component of a component tree needs an environment:
+   *
+   * ```javascript
+   *   const root = new RootComponent(env, props);
+   * ```
+   *
+   * Every other component simply needs a reference to its parent:
+   *
+   * ```javascript
+   *   const child = new SomeComponent(parent, props);
+   * ```
+   *
   * Note that most of the time, only the root component needs to be created by
   * hand.  Other components should be created automatically by the framework (with
   * the t-component directive in a template)
   */
-  constructor(parent?: Component<T, any>, props?: Props) {
-    Component.current = this;
-
-    const id: number = nextId++;
-    let depth;
-    if (parent) {
-      const defaultProps = (<any>this.constructor).defaultProps;
-      if (defaultProps) {
-        props = this.__applyDefaultProps(props, defaultProps);
-      }
-      this.props = <Props>props;
+  constructor(parent: Component<T, any> | T, props?: Props) {
+    const defaultProps = (<any>this.constructor).defaultProps;
+    Component._current = this;
+    if (defaultProps) {
+      props = this.__applyDefaultProps(props, defaultProps);
+    }
+    // is this a good idea?
+    //   Pro: if props is empty, we can create easily a component
+    //   Con: this is not really safe
+    //   Pro: but creating component (by a template) is always unsafe anyway
+    this.props = <Props>props || <Props>{};
+    let id: number = nextId++;
+    let p: Component<T, any> | null = null;
+    if (parent instanceof Component) {
+      p = parent;
+      this.env = parent.env;
+      parent.__owl__.children[id] = this;
+    } else {
+      this.env = parent;
      if (QWeb.dev) {
+        // we only validate props for root widgets here.  "Regular" widget
+        // props are validated by the t-component directive
        QWeb.utils.validateProps(this.constructor, this.props);
      }
-      this.env = parent.env;
-      const __powl__ = parent.__owl__;
-      __powl__.children[id] = this;
-      depth = __powl__.depth + 1;
-    } else {
-      // we are the root component
-      this.env = config.env as T;
-      this.props = undefined as unknown as Props;
      this.env.qweb.on("update", this, () => {
        if (this.__owl__.isMounted) {
          this.render(true);
@@ -146,19 +175,13 @@ export class Component<T extends Env, Props extends {}> {
          this.env.qweb.off("update", this);
        }
      });
-      depth = 0;
    }
-
-    const qweb = this.env.qweb;
-
    this.__owl__ = {
      id: id,
-      depth: depth,
      vnode: null,
-      pvnode: null,
      isMounted: false,
      isDestroyed: false,
-      parent: parent || null,
+      parent: p,
      children: {},
      cmap: {},
      currentFiber: null,
@@ -167,10 +190,8 @@ export class Component<T extends Env, Props extends {}> {
      willUnmountCB: null,
      willPatchCB: null,
      patchedCB: null,
-      willStartCB: null,
-      willUpdatePropsCB: null,
      observer: null,
-      renderFn: qweb.render.bind(qweb, this.__getTemplate(qweb)),
+      render: null,
      classObj: null,
      refs: null
    };
@@ -251,11 +272,8 @@ export class Component<T extends Env, Props extends {}> {
  /**
   * catchError is a method called whenever some error happens in the rendering or
   * lifecycle hooks of a child.
-   *
-   * It needs to be implemented by a component that is designed to handle the
-   * error properly.
   */
-  catchError?(error?: Error): void;
+  catchError(error: Error): void {}

  //--------------------------------------------------------------------------
  // Public
@@ -272,37 +290,28 @@ export class Component<T extends Env, Props extends {}> {
  async mount(target: HTMLElement, renderBeforeRemount: boolean = false): Promise<void> {
    const __owl__ = this.__owl__;
    if (__owl__.isMounted) {
-      return Promise.resolve();
-    }
-    if (__owl__.vnode && !renderBeforeRemount) {
-      target.appendChild(this.el!);
-      if (document.body.contains(target)) {
-        this.__callMounted();
-      }
      return;
    }
-    return new Promise((resolve, reject) => {
-      const fiber = new Fiber(null, this, undefined, undefined, false);
-      scheduler.addFiber(fiber, err => {
-        if (err) {
-          reject(err);
-          return;
-        }
-        if (!__owl__.isDestroyed) {
-          this.__patch(fiber.vnode);
-          target.appendChild(this.el!);
-          if (document.body.contains(target)) {
-            this.__callMounted();
-          }
-        }
-        resolve();
-      });
-      if (!__owl__.vnode) {
-        this.__prepareAndRender(fiber);
-      } else {
-        this.__render(fiber);
+    const fiber = this.__createFiber(false, undefined, undefined, undefined);
+    if (!__owl__.vnode) {
+      fiber.promise = this.__prepareAndRender(fiber);
+      const vnode = await fiber.promise;
+      if (__owl__.isDestroyed) {
+        // component was destroyed before we get here...
+        return;
      }
-    });
+      this.__patch(vnode);
+    } else if (renderBeforeRemount) {
+      fiber.patchQueue.push(fiber);
+      fiber.promise = this.__render(fiber);
+      await fiber.promise;
+      this.__applyPatchQueue(fiber);
+    }
+    target.appendChild(this.el!);
+
+    if (document.body.contains(target)) {
+      this.__callMounted();
+    }
  }

  /**
@@ -327,26 +336,19 @@ export class Component<T extends Env, Props extends {}> {
   */
  async render(force: boolean = false): Promise<void> {
    const __owl__ = this.__owl__;
-    if (
-      (!__owl__.isMounted && !__owl__.currentFiber) ||
-      (__owl__.currentFiber && !__owl__.currentFiber.isRendered)
-    ) {
+    if (!__owl__.isMounted) {
      return;
    }
-    return new Promise((resolve, reject) => {
-      const fiber = new Fiber(null, this, undefined, undefined, force);
-      scheduler.addFiber(fiber.root, err => {
-        if (err) {
-          reject(err);
-          return;
-        }
-        if (__owl__.isMounted && fiber === fiber.root) {
-          fiber.patchComponents();
-        }
-        resolve();
-      });
-      this.__render(fiber);
-    });
+    const fiber = this.__createFiber(force, undefined, undefined, undefined);
+    fiber.patchQueue.push(fiber);
+    fiber.promise = this.__render(fiber);
+    await fiber.promise;
+
+    if (__owl__.isMounted && fiber === __owl__.currentFiber) {
+      // we only update the vnode and the actual DOM if no other rendering
+      // occurred between now and when the render method was initially called.
+      this.__applyPatchQueue(fiber);
+    }
  }

  /**
@@ -399,6 +401,27 @@ export class Component<T extends Env, Props extends {}> {
  // Private
  //--------------------------------------------------------------------------

+  /**
+   * This method is a helper to create a fiber element.
+   */
+  __createFiber(force, scope, vars, parent?: Fiber<any>): Fiber<Props> {
+    const fiber: Fiber<Props> = {
+      force,
+      scope,
+      vars,
+      rootFiber: null,
+      isCancelled: false,
+      component: this,
+      vnode: null,
+      patchQueue: parent ? parent.patchQueue : [],
+      props: this.props,
+      promise: null
+    };
+    fiber.rootFiber = parent ? parent.rootFiber : fiber;
+    this.__owl__.currentFiber = fiber;
+    return fiber;
+  }
+
  /**
   * Private helper to perform a full destroy, from the point of view of an Owl
   * component. It does not remove the el (this is done only once on the top
@@ -414,9 +437,6 @@ export class Component<T extends Env, Props extends {}> {
    const __owl__ = this.__owl__;
    const isMounted = __owl__.isMounted;
    if (isMounted) {
-      if (__owl__.willUnmountCB) {
-        __owl__.willUnmountCB();
-      }
      this.willUnmount();
      __owl__.isMounted = false;
    }
@@ -446,10 +466,10 @@ export class Component<T extends Env, Props extends {}> {
    try {
      this.mounted();
      if (__owl__.mountedCB) {
-        __owl__.mountedCB();
+          __owl__.mountedCB()
      }
    } catch (e) {
-      console.error(e); // TODO : add a test
+      errorHandler(e, this);
    }
  }

@@ -475,38 +495,22 @@ export class Component<T extends Env, Props extends {}> {
   */
  async __updateProps(
    nextProps: Props,
-    parentFiber: Fiber,
-    scope: any,
-    vars: any,
-    previousSibling?: Fiber | null
+    parentFiber: Fiber<any>,
+    scope?: any,
+    vars?: any
  ): Promise<void> {
    const shouldUpdate = parentFiber.force || this.shouldUpdate(nextProps);
    if (shouldUpdate) {
-      const __owl__ = this.__owl__;
-      const fiber = new Fiber(parentFiber, this, scope, vars, parentFiber.force);
-      if (!parentFiber.child) {
-        parentFiber.child = fiber;
-      } else {
-        previousSibling!.sibling = fiber;
-      }
-
      const defaultProps = (<any>this.constructor).defaultProps;
      if (defaultProps) {
        nextProps = this.__applyDefaultProps(nextProps, defaultProps);
      }
-      if (QWeb.dev) {
-        QWeb.utils.validateProps(this.constructor, nextProps);
-      }
-      await Promise.all([
-        this.willUpdateProps(nextProps),
-        __owl__.willUpdatePropsCB && __owl__.willUpdatePropsCB(nextProps)
-      ]);
-      if (fiber.isCancelled) {
-        return;
-      }
+      await this.willUpdateProps(nextProps);
      this.props = nextProps;
+      const fiber = this.__createFiber(parentFiber.force, scope, vars, parentFiber);
+      fiber.patchQueue.push(fiber);

-      this.__render(fiber);
+      await this.__render(fiber);
    }
  }

@@ -518,7 +522,6 @@ export class Component<T extends Env, Props extends {}> {
    const __owl__ = this.__owl__;
    const target = __owl__.vnode || document.createElement(vnode.sel!);
    __owl__.vnode = patch(target, vnode);
-    __owl__.currentFiber = null;
  }

  /**
@@ -526,19 +529,26 @@ export class Component<T extends Env, Props extends {}> {
   * subcomponent is created. It gets its scope and vars, if any, from the
   * parent template.
   */
-  __prepare(parentFiber: Fiber, scope: any, vars: any, previousSibling?: Fiber | null) {
-    const fiber = new Fiber(parentFiber, this, scope, vars, parentFiber.force);
-    fiber.shouldPatch = false;
-    if (!parentFiber.child) {
-      parentFiber.child = fiber;
-    } else {
-      previousSibling!.sibling = fiber;
-    }
-    return this.__prepareAndRender(fiber);
+  __prepare(parentFiber: Fiber<any>, scope: any, vars: any): Promise<VNode> {
+    const fiber = this.__createFiber(parentFiber.force, scope, vars, parentFiber);
+    fiber.promise = this.__prepareAndRender(fiber);
+    return fiber.promise;
  }

-  __getTemplate(qweb: QWeb): string {
+  async __prepareAndRender(fiber: Fiber<Props>): Promise<VNode> {
+    try {
+      await this.willStart();
+    } catch (e) {
+      errorHandler(e, this);
+      return Promise.resolve(h("div"));
+    }
+    const __owl__ = this.__owl__;
+    if (__owl__.isDestroyed) {
+      return Promise.resolve(h("div"));
+    }
+    const qweb = this.env.qweb;
    let p = (<any>this).constructor;
+    // console.warn(p, p.template, p._template, 'template' in p, p.hasOwnProperty('template'))
    if (!p.hasOwnProperty("_template")) {
      if (p.template) {
        p._template = p.template;
@@ -558,68 +568,58 @@ export class Component<T extends Env, Props extends {}> {
        }
      }
    }
-    return p._template;
-  }
-  async __prepareAndRender(fiber: Fiber) {
-    try {
-      await Promise.all([this.willStart(), this.__owl__.willStartCB && this.__owl__.willStartCB()]);
-    } catch (e) {
-      fiber.handleError(e);
-      fiber.vnode = h("div"); // -> we render this div at the end
-      return Promise.resolve();
-    }
-    if (this.__owl__.isDestroyed) {
-      return Promise.resolve();
-    }
-    if (!fiber.isCancelled) {
-      this.__render(fiber);
-    }
+    __owl__.render = qweb.render.bind(qweb, p._template);
+    return this.__render(fiber);
  }

-  __render(fiber: Fiber) {
+  __render(fiber: Fiber<Props>): Promise<VNode> {
    const __owl__ = this.__owl__;
+    const promises: Promise<void>[] = [];
    if (__owl__.observer) {
      __owl__.observer.allowMutations = false;
    }
    let vnode;
    try {
-      vnode = __owl__.renderFn!(this, {
+      vnode = __owl__.render!(this, {
+        promises,
        handlers: __owl__.boundHandlers,
        fiber: fiber
      });
    } catch (e) {
      vnode = __owl__.vnode || h("div");
-      fiber.handleError(e);
+      errorHandler(e, this);
    }
    fiber.vnode = vnode;
    if (__owl__.observer) {
      __owl__.observer.allowMutations = true;
    }

-    // we apply here the class information described on the component by the
+    // this part is critical for the patching process to be done correctly. The
+    // tricky part is that a child component can be rerendered on its own, which
+    // will update its own vnode representation without the knowledge of the
+    // parent component.  With this, we make sure that the parent component will be
+    // able to patch itself properly after
+    vnode.key = __owl__.id;
+
+    // we applly here the class information described on the component by the
    // template (so, something like <MyComponent class="..."/>) to the actual
    // root vnode
    if (__owl__.classObj) {
      vnode.data.class = Object.assign(vnode.data.class || {}, __owl__.classObj);
    }
-    fiber.root.counter--;
-    fiber.isRendered = true;
+
+    return Promise.all(promises).then(() => vnode);
  }

  /**
   * Only called by qweb t-component directive
   */
-  __mount(fiber: Fiber, elm: HTMLElement): VNode {
-    if (fiber !== this.__owl__.currentFiber) {
-      fiber = this.__owl__.currentFiber!; // TODO: check if we can remove fiber arg
-    }
-    const vnode = fiber.vnode!;
+  __mount(vnode: VNode, elm: HTMLElement): VNode {
    const __owl__ = this.__owl__;
    if (__owl__.classObj) {
      (<any>vnode).data.class = Object.assign((<any>vnode).data.class || {}, __owl__.classObj);
    }
    __owl__.vnode = patch(elm, vnode);
-    __owl__.currentFiber = null;
    if (__owl__.parent!.__owl__.isMounted && !__owl__.isMounted) {
      this.__callMounted();
    }
@@ -652,4 +652,72 @@ export class Component<T extends Env, Props extends {}> {
    }
    return <Props>props;
  }
+
+  /**
+   * Apply the given patch queue from a fiber.
+   *   1) Call 'willPatch' on the component of each patch
+   *   2) Call '__patch' on the component of each patch
+   *   3) Call 'patched' on the component of each patch, in reverse order
+   */
+  __applyPatchQueue(fiber: Fiber<Props>) {
+    const patchQueue = fiber.patchQueue;
+    let component: Component<any, any> = this;
+    try {
+      const patchLen = patchQueue.length;
+      for (let i = 0; i < patchLen; i++) {
+        component = patchQueue[i].component;
+        if (component.__owl__.willPatchCB) {
+          component.__owl__.willPatchCB();
+        }
+        component.willPatch();
+      }
+      for (let i = 0; i < patchLen; i++) {
+        const fiber = patchQueue[i];
+        component = fiber.component;
+        component.__patch(fiber.vnode);
+      }
+      for (let i = patchLen - 1; i >= 0; i--) {
+        component = patchQueue[i].component;
+        component.patched();
+        if (component.__owl__.patchedCB) {
+          component.__owl__.patchedCB();
+        }
+      }
+    } catch (e) {
+      errorHandler(e, component);
+    }
+  }
+}
+
+//------------------------------------------------------------------------------
+// Error handling
+//------------------------------------------------------------------------------
+
+/**
+ * This is the global error handler for errors occurring in Owl main lifecycle
+ * methods.  Caught errors are triggered on the QWeb instance, and are
+ * potentially given to some parent component which implements `catchError`.
+ *
+ * If there are no such component, we destroy everything. This is better than
+ * being in a corrupted state.
+ */
+function errorHandler(error: Error, component: Component<any, any>) {
+  let canCatch = false;
+  let qweb = component.env.qweb;
+  let root = component;
+  while (component && !(canCatch = component.catchError !== Component.prototype.catchError)) {
+    root = component;
+    component = component.__owl__.parent!;
+  }
+  console.error(error);
+  // we trigger error on QWeb so it can be logged/handled
+  qweb.trigger("error", error);
+
+  if (canCatch) {
+    setTimeout(() => {
+      component.catchError(error);
+    });
+  } else {
+    root.destroy();
+  }
 }
@@ -1,5 +1,5 @@
 import { QWeb } from "../qweb/index";
-import { INTERP_REGEXP } from "../qweb/compilation_context";
+import { INTERP_REGEXP } from "../qweb/context";
 import { MODS_CODE } from "../qweb/extensions";

 //------------------------------------------------------------------------------
@@ -186,7 +186,7 @@ QWeb.utils.defineProxy = function defineProxy(target, source) {

 QWeb.addDirective({
  name: "component",
-  extraNames: ["props"],
+  extraNames: ["props", "keepalive", "asyncroot"],
  priority: 100,
  atNodeEncounter({ ctx, value, node, qweb }): boolean {
    ctx.addLine("//COMPONENT");
@@ -194,7 +194,9 @@ QWeb.addDirective({
    ctx.rootContext.shouldDefineQWeb = true;
    ctx.rootContext.shouldDefineParent = true;
    ctx.rootContext.shouldDefineUtils = true;
+    let keepAlive = node.getAttribute("t-keepalive") ? true : false;
    let hasDynamicProps = node.getAttribute("t-props") ? true : false;
+    let async = node.getAttribute("t-asyncroot") ? true : false;

    // t-on- events and t-transition
    const events: [string, string[], string, string][] = [];
@@ -207,11 +209,11 @@ QWeb.addDirective({
      if (name.startsWith("t-on-")) {
        const [eventName, ...mods] = name.slice(5).split(".");
        let extraArgs;
-        let handlerValue = value.replace(/\(.*\)/, function(args) {
+        let handlerName = value.replace(/\(.*\)/, function(args) {
          extraArgs = args.slice(1, -1);
          return "";
        });
-        events.push([eventName, mods, handlerValue, extraArgs]);
+        events.push([eventName, mods, handlerName, extraArgs]);
      } else if (name === "t-transition") {
        transition = value;
      } else if (!name.startsWith("t-")) {
@@ -222,25 +224,40 @@ QWeb.addDirective({
      }
    }

+    let key = node.getAttribute("t-key");
+    if (key) {
+      key = ctx.formatExpression(key);
+    }
+
    // computing the props string representing the props object
    let propStr = Object.keys(props)
      .map(k => k + ":" + props[k])
      .join(",");
+    let dummyID = ctx.generateID();
    let defID = ctx.generateID();
    let componentID = ctx.generateID();
-
-    let locationExpr = `\`__${ctx.generateID()}__`;
-    for (let i = 0; i < ctx.loopNumber - 1; i++) {
-      locationExpr += `\${i${i + 1}}__`;
+    let keyID = key && ctx.generateID();
+    if (key) {
+      // we bind a variable to the key (could be a complex expression, so we
+      // want to evaluate it only once)
+      ctx.addLine(`let key${keyID} = 'key' + ${key};`);
    }
-    if (ctx.lastNodeKey || ctx.currentKey) {
-      const k = ctx.lastNodeKey || ctx.currentKey;
-      ctx.addLine(`let templateId${componentID} = ${locationExpr}\` + ${k};`);
-    } else {
-      locationExpr += ctx.loopNumber ? `\${i${ctx.loopNumber}}__\`` : "`";
-      ctx.addLine(`let templateId${componentID} = ${locationExpr};`);
+    ctx.addLine(`let def${defID};`);
+    let templateID = key
+      ? `key${keyID}`
+      : ctx.inLoop
+      ? ctx.currentKey
+        ? `String(${ctx.currentKey} + '_k_' + i + '_c_' + ${componentID} )`
+        : `String(-${componentID} - i)`
+      : String(componentID);
+    if (ctx.allowMultipleRoots) {
+      templateID = `"_slot_${templateID}"`;
+    }
+    if (key || ctx.inLoop) {
+      let id = ctx.generateID();
+      ctx.addLine(`let templateId${id} = ${templateID};`);
+      templateID = `templateId${id}`;
    }
-    const templateId = `templateId${componentID}`;

    let ref = node.getAttribute("t-ref");
    let refExpr = "";
@@ -255,8 +272,8 @@ QWeb.addDirective({
    if (transition) {
      transitionsInsertCode = `utils.transitionInsert(vn, '${transition}');`;
    }
-    let finalizeComponentCode = `w${componentID}.destroy();`;
-    if (ref) {
+    let finalizeComponentCode = `w${componentID}.${keepAlive ? "unmount" : "destroy"}();`;
+    if (ref && !keepAlive) {
      finalizeComponentCode += `delete context.__owl__.refs[${refKey}];`;
    }
    if (transition) {
@@ -300,10 +317,10 @@ QWeb.addDirective({
        }
      }
      let eventsCode = events
-        .map(function([eventName, mods, handlerValue, extraArgs]) {
+        .map(function([eventName, mods, handlerName, extraArgs]) {
          let params = "owner";
          if (extraArgs) {
-            if (ctx.loopNumber) {
+            if (ctx.inLoop) {
              let argId = ctx.generateID();
              // we need to evaluate the arguments now, because the handler will
              // be set asynchronously later when the widget is ready, and the
@@ -314,17 +331,18 @@ QWeb.addDirective({
              params = `owner, ${ctx.formatExpression(extraArgs)}`;
            }
          }
-          let handler = `function (e) {`;
-          handler += mods
-            .map(function(mod) {
-              return T_COMPONENT_MODS_CODE[mod];
-            })
-            .join("");
-          if (handlerValue) {
-            handler += `const fn = owner['${handlerValue}'];`;
-            handler += `if (fn) { fn.call(${params}, e); } else { owner.${handlerValue}; }`;
+          let handler;
+          if (mods.length > 0) {
+            handler = `function (e) {`;
+            handler += mods
+              .map(function(mod) {
+                return T_COMPONENT_MODS_CODE[mod];
+              })
+              .join("");
+            handler += `owner['${handlerName}'].call(${params}, e);}`;
+          } else {
+            handler = `owner['${handlerName}'].bind(${params})`;
          }
-          handler += `}`;
          return `vn.elm.addEventListener('${eventName}', ${handler});`;
        })
        .join("");
@@ -334,16 +352,32 @@ QWeb.addDirective({
    }

    ctx.addLine(
-      `let w${componentID} = ${templateId} in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[${templateId}]] : false;`
+      `let w${componentID} = ${templateID} in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[${templateID}]] : false;`
    );
-    let shouldProxy = !ctx.parentNode;
-    if (shouldProxy) {
-      let id = ctx.generateID();
-      ctx.rootContext.rootNode = id;
-      shouldProxy = true;
-      ctx.rootContext.shouldDefineResult = true;
-      ctx.addLine(`let vn${id} = {};`);
-      ctx.addLine(`result = vn${id};`);
+    if (ctx.parentNode) {
+      ctx.addLine(`let _${dummyID}_index = c${ctx.parentNode}.length;`);
+    }
+    let shouldProxy = false;
+    if (async || keepAlive) {
+      ctx.addLine(
+        `const fiber${componentID} = Object.assign(Object.create(extra.fiber), {patchQueue: []});`
+      );
+    }
+    if (async) {
+      ctx.addLine(
+        `c${ctx.parentNode}.push(w${componentID} && w${componentID}.__owl__.pvnode || null);`
+      );
+    } else {
+      if (ctx.parentNode) {
+        ctx.addLine(`c${ctx.parentNode}.push(null);`);
+      } else {
+        let id = ctx.generateID();
+        ctx.rootContext.rootNode = id;
+        shouldProxy = true;
+        ctx.rootContext.shouldDefineResult = true;
+        ctx.addLine(`let vn${id} = {};`);
+        ctx.addLine(`result = vn${id};`);
+      }
    }
    if (hasDynamicProps) {
      const dynamicProp = ctx.formatExpression(node.getAttribute("t-props")!);
@@ -354,57 +388,17 @@ QWeb.addDirective({
    ctx.addIf(
      `w${componentID} && w${componentID}.__owl__.currentFiber && !w${componentID}.__owl__.vnode`
    );
+    ctx.addIf(
+      `utils.shallowEqual(props${componentID}, w${componentID}.__owl__.currentFiber.props)`
+    );
+    ctx.addLine(`def${defID} = w${componentID}.__owl__.currentFiber.promise;`);
+    ctx.addElse();
    ctx.addLine(`w${componentID}.destroy();`);
    ctx.addLine(`w${componentID} = false;`);
    ctx.closeIf();
+    ctx.closeIf();

-    let registerCode = "";
-    if (shouldProxy) {
-      registerCode = `utils.defineProxy(vn${ctx.rootNode}, pvnode);`;
-    }
-
-    // SLOTS
-    const varDefs: string[] = [];
-    const hasSlots = node.childNodes.length;
-    if (hasSlots) {
-      ctx.rootContext.shouldTrackScope = true;
-      for (let v of Object.values(ctx.variables)) {
-        if (v["id"]) {
-          varDefs.push(v["id"]);
-        }
-      }
-    }
-
-    let scopeVars;
-    if (hasSlots) {
-      let scope = ctx.scopeVars.length ? `Object.assign({}, scope)` : `{}`;
-      let vars = varDefs.length ? `{${varDefs.join(",")}}` : "undefined";
-      scopeVars = `${scope}, ${vars}`;
-    } else {
-      scopeVars = "undefined, undefined";
-    }
-
-    ctx.addIf(`w${componentID}`);
-
-    // need to update component
-    let styleCode = "";
-    if (tattStyle) {
-      styleCode = `.then(()=>{if (w${componentID}.__owl__.isDestroyed) {return};w${componentID}.el.style=${tattStyle};});`;
-    }
-    ctx.addLine(
-      `w${componentID}.__updateProps(props${componentID}, extra.fiber${scopeVars &&
-        ", " + scopeVars}, sibling)${styleCode};`
-    );
-    ctx.addLine(`let pvnode = w${componentID}.__owl__.pvnode;`);
-    if (registerCode) {
-      ctx.addLine(registerCode);
-    }
-    if (ctx.parentNode) {
-      ctx.addLine(`c${ctx.parentNode}.push(pvnode);`);
-    }
-
-    ctx.addElse();
-
+    ctx.addIf(`!w${componentID}`);
    // new component
    let dynamicFallback = "";
    if (!value.match(INTERP_REGEXP)) {
@@ -420,10 +414,23 @@ QWeb.addDirective({
    ctx.addLine(
      `if (!W${componentID}) {throw new Error('Cannot find the definition of component "' + componentKey${componentID} + '"')}`
    );
+    if (QWeb.dev) {
+      ctx.addLine(`utils.validateProps(W${componentID}, props${componentID})`);
+    }
    ctx.addLine(`w${componentID} = new W${componentID}(parent, props${componentID});`);
-    ctx.addLine(`parent.__owl__.cmap[${templateId}] = w${componentID}.__owl__.id;`);
+    ctx.addLine(`parent.__owl__.cmap[${templateID}] = w${componentID}.__owl__.id;`);

+    // SLOTS
+    const varDefs: string[] = [];
+    const hasSlots = node.childNodes.length;
    if (hasSlots) {
+      ctx.rootContext.shouldTrackScope = true;
+      for (let v of Object.values(ctx.variables)) {
+        if (v["id"]) {
+          varDefs.push(v["id"]);
+        }
+      }
+
      const clone = <Element>node.cloneNode(true);
      const slotNodes = clone.querySelectorAll("[t-set]");
      const slotId = QWeb.nextSlotId++;
@@ -448,30 +455,67 @@ QWeb.addDirective({
      }
    }

-    ctx.addLine(`let def${defID} = w${componentID}.__prepare(extra.fiber, ${scopeVars}, sibling);`);
+    let scopeVars;
+    if (hasSlots) {
+      let scope = ctx.scopeVars.length ? `Object.assign({}, scope)` : `{}`;
+      let vars = varDefs.length ? `{${varDefs.join(",")}}` : "undefined";
+      scopeVars = `${scope}, ${vars}`;
+    } else {
+      scopeVars = "undefined, undefined";
+    }
+    ctx.addLine(`def${defID} = w${componentID}.__prepare(extra.fiber, ${scopeVars});`);
    // hack: specify empty remove hook to prevent the node from being removed from the DOM
-    ctx.addLine(
-      `let pvnode = h('dummy', {key: ${templateId}, hook: {insert(vn) { let nvn=w${componentID}.__mount(fiber, pvnode.elm);pvnode.elm=nvn.elm;${refExpr}${transitionsInsertCode}},remove() {},destroy(vn) {${finalizeComponentCode}}}});`
-    );
-    ctx.addLine(`const fiber = w${componentID}.__owl__.currentFiber;`);
-    ctx.addLine(
-      `def${defID}.then(function () {if (w${componentID}.__owl__.isDestroyed) {return;} const vnode = fiber.vnode; pvnode.sel = vnode.sel; ${createHook}});`
-    );
-    if (registerCode) {
-      ctx.addLine(registerCode);
+    let registerCode = `c${ctx.parentNode}[_${dummyID}_index]=pvnode;`;
+    if (shouldProxy) {
+      registerCode = `utils.defineProxy(vn${ctx.rootNode}, pvnode);`;
    }
-    if (ctx.parentNode) {
-      ctx.addLine(`c${ctx.parentNode}.push(pvnode);`);
-    }
-    ctx.addLine(`w${componentID}.__owl__.pvnode = pvnode;`);
+    ctx.addLine(
+      `def${defID} = def${defID}.then(vnode=>{if (w${componentID}.__owl__.isDestroyed){return}${createHook}let pvnode=h(vnode.sel, {key: ${templateID}, hook: {insert(vn) {let nvn=w${componentID}.__mount(vnode, pvnode.elm);pvnode.elm=nvn.elm;${refExpr}${transitionsInsertCode}},remove() {},destroy(vn) {${finalizeComponentCode}}}});${registerCode}w${componentID}.__owl__.pvnode = pvnode;});`
+    );

+    ctx.addElse();
+    // need to update component
+    let patchQueueCode = async || keepAlive ? `fiber${componentID}` : "extra.fiber";
+    if (keepAlive) {
+      // if we have t-keepalive="1", the component could be unmounted, but then
+      // we __updateProps is called.  This is ok, but we do not want to call
+      // the willPatch/patched hooks of the component in this case, so we
+      // disable the patch queue
+      patchQueueCode = `w${componentID}.__owl__.isMounted ? extra.fiber : fiber${componentID}`;
+    }
+    if (QWeb.dev) {
+      ctx.addLine(`utils.validateProps(w${componentID}.constructor, props${componentID})`);
+    }
+    ctx.addLine(
+      `def${defID} = def${defID} || w${componentID}.__updateProps(props${componentID}, ${patchQueueCode}${scopeVars &&
+        ", " + scopeVars});`
+    );
+    let keepAliveCode = "";
+    if (keepAlive) {
+      keepAliveCode = `pvnode.data.hook.insert = vn => {vn.elm.parentNode.replaceChild(w${componentID}.el,vn.elm);vn.elm=w${componentID}.el;w${componentID}.__remount();};`;
+    }
+    ctx.addLine(
+      `def${defID} = def${defID}.then(()=>{if (w${componentID}.__owl__.isDestroyed) {return};${
+        tattStyle ? `w${componentID}.el.style=${tattStyle};` : ""
+      }let pvnode=w${componentID}.__owl__.pvnode;${keepAliveCode}${registerCode}});`
+    );
    ctx.closeIf();

    if (classObj) {
      ctx.addLine(`w${componentID}.__owl__.classObj=${classObj};`);
    }

-    ctx.addLine(`sibling = w${componentID}.__owl__.currentFiber || sibling;`);
+    if (async) {
+      ctx.addLine(
+        `def${defID}.then(w${componentID}.__applyPatchQueue.bind(w${componentID}, fiber${componentID}));`
+      );
+    } else {
+      ctx.addLine(`extra.promises.push(def${defID});`);
+    }
+
+    if (node.hasAttribute("t-if") || node.hasAttribute("t-else") || node.hasAttribute("t-elif")) {
+      ctx.closeIf();
+    }

    return true;
  }
@@ -1,226 +0,0 @@
-import { VNode } from "../vdom/index";
-import { Component } from "./component";
-import { scheduler } from "./scheduler";
-
-/**
- * Owl Fiber Class
- *
- * Fibers are small abstractions designed to contain all the internal state
- * associated with a "rendering work unit", relative to a specific component.
- *
- * A rendering will cause the creation of a fiber for each impacted components.
- *
- * Fibers capture all that necessary information, which is critical to owl
- * asynchronous rendering pipeline. Fibers can be cancelled, can be in different
- * states and in general determine the state of the rendering.
- */
-
-export class Fiber {
-  // The force attribute determines if a rendering should bypass the `shouldUpdate`
-  // method potentially implemented by a component. It is usually set to false.
-  force: boolean;
-
-  // isCancelled means that the rendering corresponding to this fiber and its
-  // children is cancelled. No extra work should be done.
-  isCancelled: boolean = false;
-
-  // the fibers corresponding to component updates (updateProps) need to call
-  // the willPatch and patched hooks from the corresponding component. However,
-  // fibers corresponding to a new component do not need to do that. So, the
-  // shouldPatch hook is the boolean that we check whenever we need to apply
-  // a patch.
-  shouldPatch: boolean = true;
-
-  // isRendered is the last state of a fiber. If true, this means that it has
-  // been rendered and is inert (so, it should not be taken into account when
-  // counting the number of active fibers).
-  isRendered: boolean = false;
-
-  // the counter number is a critical information. It is only necessary for a
-  // root fiber.  For that fiber, this number counts the number of active sub
-  // fibers.  When that number reaches 0, the fiber can be applied by the
-  // scheduler.
-  counter: number = 0;
-
-  scope: any;
-  vars: any;
-
-  component: Component<any, any>;
-  vnode: VNode | null = null;
-
-  root: Fiber;
-  child: Fiber | null = null;
-  sibling: Fiber | null = null;
-  parent: Fiber | null = null;
-
-  error?: Error;
-
-  constructor(parent: Fiber | null, component: Component<any, any>, scope, vars, force) {
-    this.force = force;
-    this.scope = scope;
-    this.vars = vars;
-    this.component = component;
-
-    this.root = parent ? parent.root : this;
-    this.parent = parent;
-
-    let oldFiber = component.__owl__.currentFiber;
-    if (oldFiber && !oldFiber.isCancelled) {
-      this._remapFiber(oldFiber);
-    }
-
-    this.root.counter++;
-
-    component.__owl__.currentFiber = this;
-  }
-
-  /**
-   * In some cases, a rendering initiated at some component can detect that it
-   * should be part of a larger rendering initiated somewhere up the component
-   * tree.  In that case, it needs to cancel the previous rendering and
-   * remap itself as a part of the current parent rendering.
-   */
-  _remapFiber(oldFiber: Fiber) {
-    oldFiber.cancel();
-    if (oldFiber === oldFiber.root) {
-      oldFiber.root.counter++;
-    }
-    if (oldFiber.parent && !this.parent) {
-      // re-map links
-      this.parent = oldFiber.parent;
-      this.root = this.parent.root;
-      this.sibling = oldFiber.sibling;
-      if (this.parent.child === oldFiber) {
-        this.parent.child = this;
-      } else {
-        let current = this.parent.child!;
-        while (true) {
-          if (current.sibling === oldFiber) {
-            current.sibling = this;
-            break;
-          }
-          current = current.sibling!;
-        }
-      }
-    }
-  }
-
-  /**
-   * This function has been taken from
-   * https://medium.com/react-in-depth/the-how-and-why-on-reacts-usage-of-linked-list-in-fiber-67f1014d0eb7
-   */
-  _walk(doWork: (f: Fiber) => Fiber | null) {
-    let root = this;
-    let current: Fiber = this;
-    while (true) {
-      const child = doWork(current);
-      if (child) {
-        current = child;
-        continue;
-      }
-      if (current === root) {
-        return;
-      }
-      while (!current.sibling) {
-        if (!current.parent || current.parent === root) {
-          return;
-        }
-        current = current.parent;
-      }
-      current = current.sibling;
-    }
-  }
-
-  /**
-   * Apply the given patch queue from a fiber.
-   *   1) Call 'willPatch' on the component of each patch
-   *   2) Call '__patch' on the component of each patch
-   *   3) Call 'patched' on the component of each patch, in reverse order
-   */
-  patchComponents() {
-    const patchQueue: Fiber[] = [];
-    const doWork: (Fiber) => Fiber | null = function(f) {
-      if (f.shouldPatch) {
-        patchQueue.push(f);
-      }
-      return f.child;
-    };
-    this._walk(doWork);
-    let component: Component<any, any> = this.component;
-    const patchLen = patchQueue.length;
-    try {
-      for (let i = 0; i < patchLen; i++) {
-        component = patchQueue[i].component;
-        if (component.__owl__.willPatchCB) {
-          component.__owl__.willPatchCB();
-        }
-        component.willPatch();
-      }
-    } catch (e) {
-      console.error(e);
-    }
-    for (let i = 0; i < patchLen; i++) {
-      const fiber = patchQueue[i];
-      component = fiber.component;
-      component.__patch(fiber.vnode);
-    }
-    try {
-      for (let i = patchLen - 1; i >= 0; i--) {
-        component = patchQueue[i].component;
-        component.patched();
-        if (component.__owl__.patchedCB) {
-          component.__owl__.patchedCB();
-        }
-      }
-    } catch (e) {
-      console.error(e);
-    }
-  }
-
-  /**
-   * Cancel a fiber and all its children.
-   */
-  cancel() {
-    this._walk(f => {
-      if (!f.isRendered) {
-        f.root.counter--;
-      }
-      f.isCancelled = true;
-      return f.child;
-    });
-  }
-
-  /**
-   * This is the global error handler for errors occurring in Owl main lifecycle
-   * methods.  Caught errors are triggered on the QWeb instance, and are
-   * potentially given to some parent component which implements `catchError`.
-   *
-   * If there are no such component, we destroy everything. This is better than
-   * being in a corrupted state.
-   */
-  handleError(error: Error) {
-    let canCatch = false;
-    let component = this.component;
-    let qweb = component.env.qweb;
-    let root = component;
-    while (component && !(canCatch = !!component.catchError)) {
-      root = component;
-      component = component.__owl__.parent!;
-    }
-    qweb.trigger("error", error);
-
-    if (canCatch) {
-      setTimeout(() => {
-        console.error(error);
-        component.catchError!(error);
-      });
-    } else {
-      // the 3 next lines aim to mark the root fiber as being in error, and
-      // to force it to end, without waiting for its children
-      this.root.counter = 0;
-      this.root.error = error;
-      scheduler.flush();
-      root.destroy();
-    }
-  }
-}
@@ -21,7 +21,7 @@ QWeb.utils.validateProps = function(Widget, props: Object) {
        // optional prop
        break;
      }
-      if (!(propName in props)) {
+      if (!props[propName]) {
        throw new Error(`Missing props '${propsDef[i]}' (component '${Widget.name}')`);
      }
    }
@@ -1,70 +0,0 @@
-import { Fiber } from "./fiber";
-
-/**
- * Owl Scheduler Class
- *
- * The scheduler is the part of Owl that will effectively apply a rendering
- * whenever a fiber is ready.
- *
- * Briefly, it can be used to register root fibers.  Whenever there is an
- * active root fiber, it will poll continuously each animation frame (so, about
- * once every 16ms) and whenever a root fiber is ready, it will apply it.
- */
-
-interface Task {
-  fiber: Fiber;
-  callback: (err?: Error) => void;
-}
-
-export class Scheduler {
-  tasks: Task[] = [];
-  isRunning: boolean = false;
-  requestAnimationFrame: typeof window.requestAnimationFrame;
-
-  constructor(requestAnimationFrame) {
-    this.requestAnimationFrame = requestAnimationFrame;
-  }
-
-  addFiber(fiber, callback) {
-    this.tasks.push({ fiber, callback });
-    if (this.isRunning) {
-      return;
-    }
-    this.scheduleTasks();
-  }
-
-  /**
-   * Process all current tasks. This only applies to the fibers that are ready.
-   * Other tasks are left unchanged.
-   */
-  flush() {
-    let tasks = this.tasks;
-    this.tasks = [];
-    tasks = tasks.filter(task => {
-      if (task.fiber.isCancelled) {
-        return false;
-      }
-      if (task.fiber.counter === 0) {
-        task.callback(task.fiber.error);
-        return false;
-      }
-      return true;
-    });
-    this.tasks = tasks.concat(this.tasks);
-  }
-
-  scheduleTasks() {
-    this.isRunning = true;
-    this.requestAnimationFrame(() => {
-      this.flush();
-      if (this.tasks.length > 0) {
-        this.scheduleTasks();
-      } else {
-        this.isRunning = false;
-      }
-    });
-  }
-}
-
-const raf = window.requestAnimationFrame.bind(window);
-export const scheduler = new Scheduler(raf);
@@ -1,48 +0,0 @@
-import { QWeb } from "./qweb/index";
-import { Env } from "./component/component";
-
-/**
- * This file creates and exports the OWL 'config' object, with keys:
- *  - 'mode': 'prod' or 'dev',
- *  - 'env': the environment to use in root components.
- */
-
-interface Config {
-  env: Env;
-  mode: string;
-}
-
-export const config = {} as Config;
-
-Object.defineProperty(config, "mode", {
-  get() {
-    return QWeb.dev ? "dev" : "prod";
-  },
-  set(mode: string) {
-    QWeb.dev = mode === "dev";
-    if (QWeb.dev) {
-      const url = `https://github.com/odoo/owl/blob/master/doc/tooling.md#development-mode`;
-      console.warn(
-        `Owl is running in 'dev' mode.  This is not suitable for production use. See ${url} for more information.`
-      );
-    } else {
-      console.log(`Owl is now running in 'prod' mode.`);
-    }
-  },
-});
-
-let env:Env;
-Object.defineProperty(config, "env", {
-  get() {
-    if (!env) {
-      env = {} as Env;
-    }
-    if (!env.qweb) {
-      env.qweb = new QWeb();
-    }
-    return env;
-  },
-  set(newEnv: Env) {
-    env = newEnv;
-  },
-});
@@ -1,143 +0,0 @@
-import { Component } from "./component/component";
-import { scheduler } from "./component/scheduler";
-import { EventBus } from "./core/event_bus";
-import { Observer } from "./core/observer";
-import { onWillUnmount } from "./hooks";
-/**
- * The `Context` object provides a way to share data between an arbitrary number
- * of component. Usually, data is passed from a parent to its children component,
- * but when we have to deal with some mostly global information, this can be
- * annoying, since each component will need to pass the information to each
- * children, even though some or most of them will not use the information.
- *
- * With a `Context` object, each component can subscribe (with the `useContext`
- * hook) to its state, and will be updated whenever the context state is updated.
- */
-
-function partitionBy<T>(arr: T[], fn: (t: T) => boolean) {
-  let lastGroup: T[] | false = false;
-  let lastValue;
-  return arr.reduce((acc: T[][], cur) => {
-    let curVal = fn(cur);
-    if (lastGroup) {
-      if (curVal === lastValue) {
-        lastGroup.push(cur);
-      } else {
-        lastGroup = false;
-      }
-    }
-    if (!lastGroup) {
-      lastGroup = [cur];
-      acc.push(lastGroup);
-    }
-    lastValue = curVal;
-    return acc;
-  }, []);
-}
-
-export class Context extends EventBus {
-  state: any;
-  observer: Observer;
-  rev: number = 1;
-  // mapping from component id to last observed context id
-  mapping: { [componentId: number]: number } = {};
-
-  constructor(state: Object = {}) {
-    super();
-    this.observer = new Observer();
-    this.observer.notifyCB = this.__notifyComponents.bind(this);
-    this.state = this.observer.observe(state);
-    this.subscriptions.update = [];
-  }
-
-  /**
-   * Instead of using trigger to emit an update event, we actually implement
-   * our own function to do that.  The reason is that we need to be smarter than
-   * a simple trigger function: we need to wait for parent components to be
-   * done before doing children components.  More precisely, if an update
-   * as an effect of destroying a children, we do not want to call any code
-   * from the child, and certainly not render it.
-   *
-   * This method implements a simple grouping algorithm by depth. If we have
-   * connected components of depths [2, 4,4,4,4, 3,8,8], the Context will notify
-   * them in the following groups: [2], [4,4,4,4], [3], [8,8]. Each group will
-   * be updated sequentially, but each components in a given group will be done in
-   * parallel.
-   *
-   * This is a very simple algorithm, but it avoids checking if a given
-   * component is a child of another.
-   */
-  async __notifyComponents() {
-    const rev = ++this.rev;
-    const subscriptions = this.subscriptions.update;
-    const groups = partitionBy(subscriptions, s => (s.owner ? s.owner.__owl__.depth : -1));
-    for (let group of groups) {
-      const proms = Promise.all(
-        group.map(sub => {
-          if (sub.owner ? sub.owner.__owl__.isMounted : true) {
-            return sub.callback.call(sub.owner, rev);
-          }
-        })
-      );
-      // at this point, each component in the current group has registered a
-      // top level fiber in the scheduler. It could happen that rendering these
-      // components is done (if they have no children).  This is why we manually
-      // flush the scheduler.  This will force the scheduler to check
-      // immediately if they are done, which will cause their rendering
-      // promise to resolve earlier, which means that there is a chance of
-      // processing the next group in the same frame.
-      scheduler.flush();
-      await proms;
-    }
-  }
-}
-
-/**
- * The`useContext` hook is the normal way for a component to register themselve
- * to context state changes. The `useContext` method returns the context state
- */
-export function useContext(ctx: Context): any {
-  const component: Component<any, any> = Component.current!;
-  return useContextWithCB(ctx, component, component.render.bind(component));
-}
-
-export function useContextWithCB(ctx: Context, component: Component<any, any>, method): any {
-  const __owl__ = component.__owl__;
-  const id = __owl__.id;
-  const mapping = ctx.mapping;
-  if (id in mapping) {
-    return ctx.state;
-  }
-  if (!__owl__.observer) {
-    __owl__.observer = new Observer();
-    __owl__.observer.notifyCB = component.render.bind(component);
-  }
-  const currentCB = __owl__.observer.notifyCB;
-  __owl__.observer.notifyCB = function() {
-    if (ctx.rev > mapping[id]) {
-      // in this case, the context has been updated since we were rendering
-      // last, and we do not need to render here with the observer. A
-      // rendering is coming anyway, with the correct props.
-      return;
-    }
-    currentCB();
-  };
-
-  mapping[id] = 0;
-  const renderFn = __owl__.renderFn;
-  __owl__.renderFn = function(comp, params) {
-    mapping[id] = ctx.rev;
-    return renderFn(comp, params);
-  };
-  ctx.on("update", component, async contextRev => {
-    if (mapping[id] < contextRev) {
-      mapping[id] = contextRev;
-      await method();
-    }
-  });
-  onWillUnmount(() => {
-    ctx.off("update", component);
-    delete mapping[id];
-  });
-  return ctx.state;
-}
@@ -46,6 +46,10 @@ export class Observer {
    const metadata = this.weakMap.get(value);
    return metadata ? metadata.rev : 0;
  }
+  deepRevNumber(value): number {
+    const metadata = this.weakMap.get(value);
+    return metadata ? metadata.deepRev : 0;
+  }

  _observe(value, parent) {
    var self = this;
@@ -83,6 +87,7 @@ export class Observer {
      value,
      proxy,
      rev: this.rev,
+      deepRev: this.rev,
      parent
    };

@@ -94,10 +99,11 @@ export class Observer {
  _updateRevNumber(target: any) {
    this.rev++;
    let metadata = this.weakMap.get(target);
+    metadata.rev!++;
    let parent = target;
    do {
      metadata = this.weakMap.get(parent);
-      metadata.rev++;
+      metadata.deepRev++;
    } while ((parent = metadata.parent) && parent !== target);
  }
 }
@@ -22,7 +22,7 @@ import { Observer } from "./core/observer";
 * trigger a rerendering of the current component.
 */
 export function useState<T>(state: T): T {
-  const component: Component<any, any> = Component.current!;
+  const component: Component<any, any> = Component._current;
  const __owl__ = component.__owl__;
  if (!__owl__.observer) {
    __owl__.observer = new Observer();
@@ -35,43 +35,21 @@ export function useState<T>(state: T): T {
 // Life cycle hooks
 // -----------------------------------------------------------------------------
 function makeLifecycleHook(method: string, reverse: boolean = false) {
-  if (reverse) {
-    return function(cb) {
-      const component: Component<any, any> = Component.current!;
-      if (component.__owl__[method]) {
-        const current = component.__owl__[method];
-        component.__owl__[method] = function() {
-          current.call(component);
-          cb.call(component);
-        };
-      } else {
-        component.__owl__[method] = cb;
-      }
-    };
-  } else {
-    return function(cb) {
-      const component: Component<any, any> = Component.current!;
-      if (component.__owl__[method]) {
-        const current = component.__owl__[method];
-        component.__owl__[method] = function() {
-          cb.call(component);
-          current.call(component);
-        };
-      } else {
-        component.__owl__[method] = cb;
-      }
-    };
-  }
-}
-
-function makeAsyncHook(method: string) {
  return function(cb) {
-    const component: Component<any, any> = Component.current!;
+    const component: Component<any, any> = Component._current;
    if (component.__owl__[method]) {
      const current = component.__owl__[method];
-      component.__owl__[method] = function(...args) {
-        return Promise.all[(current.call(component, ...args), cb.call(component, ...args))];
-      };
+      if (reverse) {
+        component.__owl__[method] = function() {
+          current.call(component);
+          cb.call(component);
+        };
+      } else {
+        component.__owl__[method] = function() {
+          cb.call(component);
+          current.call(component);
+        };
+      }
    } else {
      component.__owl__[method] = cb;
    }
@@ -83,9 +61,6 @@ export const onWillUnmount = makeLifecycleHook("willUnmountCB");
 export const onWillPatch = makeLifecycleHook("willPatchCB");
 export const onPatched = makeLifecycleHook("patchedCB", true);

-export const onWillStart = makeAsyncHook("willStartCB");
-export const onWillUpdateProps = makeAsyncHook("willUpdatePropsCB");
-
 // -----------------------------------------------------------------------------
 // useRef
 // -----------------------------------------------------------------------------
@@ -100,7 +75,7 @@ interface Ref {
 }

 export function useRef(name: string): Ref {
-  const __owl__ = Component.current!.__owl__;
+  const __owl__ = Component._current.__owl__;
  return {
    get el(): HTMLElement | null {
      const val = __owl__.refs && __owl__.refs[name];
@@ -117,12 +92,13 @@ export function useRef(name: string): Ref {
 // useSubEnv
 // -----------------------------------------------------------------------------

+
 /**
 * This hook is a simple way to let components use a sub environment.  Note that
 * like for all hooks, it is important that this is only called in the
 * constructor method.
 */
 export function useSubEnv(nextEnv) {
-  const component = Component.current!;
+  const component = Component._current;
  component.env = Object.assign(Object.create(component.env), nextEnv);
-}
+}
@@ -7,33 +7,40 @@
 import { EventBus } from "./core/event_bus";
 import { Observer } from "./core/observer";
 import { QWeb } from "./qweb/index";
-import { config } from "./config";
-import * as _store from "./store";
+import { ConnectedComponent } from "./store/connected_component";
+import { Store } from "./store/store";
 import * as _utils from "./utils";
 import * as _tags from "./tags";
-import { AsyncRoot } from "./misc/async_root";
 import * as _hooks from "./hooks";
-import * as _context from "./context";
-import { Link } from "./router/link";
-import { RouteComponent } from "./router/route_component";
-import { Router } from "./router/router";
+import { Link } from "./router/Link";
+import { RouteComponent } from "./router/RouteComponent";
+import { Router } from "./router/Router";

 export { Component } from "./component/component";
 export { QWeb };
-export { config };

-export const Context = _context.Context;
 export const useState = _hooks.useState;
 export const core = { EventBus, Observer };
 export const router = { Router, RouteComponent, Link };
-export const Store = _store.Store;
+export const store = { Store, ConnectedComponent };
 export const utils = _utils;
 export const tags = _tags;
-export const misc = { AsyncRoot };
-export const hooks = Object.assign({}, _hooks, {
-  useContext: _context.useContext,
-  useDispatch: _store.useDispatch,
-  useGetters: _store.useGetters,
-  useStore: _store.useStore
-});
+export const hooks = _hooks;
 export const __info__ = {};
+
+Object.defineProperty(__info__, "mode", {
+  get() {
+    return QWeb.dev ? "dev" : "prod";
+  },
+  set(mode: string) {
+    QWeb.dev = mode === "dev";
+    if (QWeb.dev) {
+      const url = `https://github.com/odoo/owl/blob/master/doc/tooling.md#development-mode`;
+      console.warn(
+        `Owl is running in 'dev' mode.  This is not suitable for production use. See ${url} for more information.`
+      );
+    } else {
+      console.log(`Owl is now running in 'prod' mode.`);
+    }
+  }
+});
@@ -1,19 +0,0 @@
-import { Component } from "../component/component";
-import { xml } from "../tags";
-
-/**
- * AsyncRoot
- *
- * Owl is by default asynchronous, and the user interface will wait for all its
- * subcomponents to be rendered before updating the DOM. This is most of the
- * time what we want, but in some cases, it makes sense to "detach" a component
- * from this coordination.  This is the goal of the AsyncRoot component.
- */
-
-export class AsyncRoot extends Component<any, any> {
-  static template = xml`<t t-slot="default"/>`;
-
-  async __updateProps(nextProps, parentFiber) {
-    this.render(parentFiber.force);
-  }
-}
@@ -1,7 +1,6 @@
-import { CompilationContext } from "./compilation_context";
+import { Context } from "./context";
 import { QWebExprVar } from "./expression_parser";
 import { QWeb } from "./qweb";
-import { htmlToVDOM } from "../vdom/html_to_vdom";

 /**
 * Owl QWeb Directives
@@ -26,9 +25,7 @@ QWeb.utils.getFragment = function(str: string): DocumentFragment {
  return temp.content;
 };

-QWeb.utils.htmlToVDOM = htmlToVDOM;
-
-function compileValueNode(value: any, node: Element, qweb: QWeb, ctx: CompilationContext) {
+function compileValueNode(value: any, node: Element, qweb: QWeb, ctx: Context) {
  if (value === "0" && ctx.caller) {
    qweb._compileNode(ctx.caller, ctx);
    return;
@@ -58,13 +55,18 @@ function compileValueNode(value: any, node: Element, qweb: QWeb, ctx: Compilatio
      ctx.rootContext.rootNode = nodeID;
      ctx.rootContext.parentTextNode = nodeID;
      ctx.addLine(`var vn${nodeID} = {text: ${exprID}};`);
-      if (ctx.rootContext.shouldDefineResult) {
-        ctx.addLine(`result = vn${nodeID}`);
-      }
+      ctx.addLine(`result = vn${nodeID}`);
    }
  } else {
+    let fragID = ctx.generateID();
    ctx.rootContext.shouldDefineUtils = true;
-    ctx.addLine(`c${ctx.parentNode}.push(...utils.htmlToVDOM(${exprID}));`);
+    ctx.addLine(`var frag${fragID} = utils.getFragment(${exprID})`);
+    let tempNodeID = ctx.generateID();
+    ctx.addLine(`var p${tempNodeID} = {hook: {`);
+    ctx.addLine(`  insert: n => n.elm.parentNode.replaceChild(frag${fragID}, n.elm),`);
+    ctx.addLine(`}};`);
+    ctx.addLine(`var vn${tempNodeID} = h('div', p${tempNodeID})`);
+    ctx.addLine(`c${ctx.parentNode}.push(vn${tempNodeID});`);
  }
  if (node.childNodes.length) {
    ctx.addElse();
@@ -78,6 +80,11 @@ QWeb.addDirective({
  name: "esc",
  priority: 70,
  atNodeEncounter({ node, qweb, ctx }): boolean {
+    if (node.nodeName !== "t") {
+      let nodeID = qweb._compileGenericNode(node, ctx);
+      ctx = ctx.withParent(nodeID);
+      ctx = ctx.subContext("currentKey", ctx.lastNodeKey);
+    }
    let value = ctx.getValue(node.getAttribute("t-esc")!);
    compileValueNode(value, node, qweb, ctx.subContext("escaping", true));
    return true;
@@ -88,6 +95,11 @@ QWeb.addDirective({
  name: "raw",
  priority: 80,
  atNodeEncounter({ node, qweb, ctx }): boolean {
+    if (node.nodeName !== "t") {
+      let nodeID = qweb._compileGenericNode(node, ctx);
+      ctx = ctx.withParent(nodeID);
+      ctx = ctx.subContext("currentKey", ctx.lastNodeKey);
+    }
    let value = ctx.getValue(node.getAttribute("t-raw")!);
    compileValueNode(value, node, qweb, ctx);
    return true;
@@ -133,7 +145,7 @@ QWeb.addDirective({
  priority: 20,
  atNodeEncounter({ node, ctx }): boolean {
    let cond = ctx.getValue(node.getAttribute("t-if")!);
-    ctx.addIf(typeof cond === "string" ? ctx.formatExpression(cond) : cond.id);
+    ctx.addIf(`${ctx.formatExpression(cond)}`);
    return false;
  },
  finalize({ ctx }) {
@@ -146,7 +158,7 @@ QWeb.addDirective({
  priority: 30,
  atNodeEncounter({ node, ctx }): boolean {
    let cond = ctx.getValue(node.getAttribute("t-elif")!);
-    ctx.addLine(`else if (${typeof cond === "string" ? ctx.formatExpression(cond) : cond.id}) {`);
+    ctx.addLine(`else if (${ctx.formatExpression(cond)}) {`);
    ctx.indent();
    return false;
  },
@@ -187,7 +199,7 @@ QWeb.addDirective({
    nodeCopy.removeAttribute("t-call");

    // extract variables from nodecopy
-    const tempCtx = new CompilationContext();
+    const tempCtx = new Context();
    tempCtx.nextID = ctx.rootContext.nextID;
    tempCtx.allowMultipleRoots = true;
    qweb._compileNode(nodeCopy, tempCtx);
@@ -258,6 +270,10 @@ QWeb.addDirective({
      ctx.addLine("}");
    }

+    if (node.hasAttribute("t-if") || node.hasAttribute("t-else") || node.hasAttribute("t-elif")) {
+      ctx.closeIf();
+    }
+
    return true;
  }
 });
@@ -271,7 +287,7 @@ QWeb.addDirective({
  priority: 10,
  atNodeEncounter({ node, qweb, ctx }): boolean {
    ctx.rootContext.shouldProtectContext = true;
-    ctx = ctx.subContext("loopNumber", ctx.loopNumber + 1);
+    ctx = ctx.subContext("inLoop", true);
    const elems = node.getAttribute("t-foreach")!;
    const name = node.getAttribute("t-as")!;
    let arrayID = ctx.generateID();
@@ -285,26 +301,33 @@ QWeb.addDirective({
    ctx.addLine(`_${valuesID} = Object.values(_${arrayID});`);
    ctx.closeIf();
    ctx.addLine(`var _length${keysID} = _${keysID}.length;`);
-    const loopVar = `i${ctx.loopNumber}`;
-    ctx.addLine(`for (let ${loopVar} = 0; ${loopVar} < _length${keysID}; ${loopVar}++) {`);
+    ctx.addLine(`for (let i = 0; i < _length${keysID}; i++) {`);
    ctx.indent();
-    ctx.addToScope(name + "_first", `${loopVar} === 0`);
-    ctx.addToScope(name + "_last", `${loopVar} === _length${keysID} - 1`);
-    ctx.addToScope(name + "_index", loopVar);
-    ctx.addToScope(name, `_${keysID}[${loopVar}]`);
-    ctx.addToScope(name + "_value", `_${valuesID}[${loopVar}]`);
+    ctx.addToScope(name + "_first", "i === 0");
+    ctx.addToScope(name + "_last", `i === _length${keysID} - 1`);
+    ctx.addToScope(name + "_index", "i");
+    ctx.addToScope(name, `_${keysID}[i]`);
+    ctx.addToScope(name + "_value", `_${valuesID}[i]`);
    const nodeCopy = <Element>node.cloneNode(true);
-    let shouldWarn =
-      !nodeCopy.hasAttribute("t-key") &&
-      node.children.length === 1 &&
-      node.children[0].tagName !== "t" &&
-      !node.children[0].hasAttribute("t-key");
+    let shouldWarn = nodeCopy.tagName !== "t" && !nodeCopy.hasAttribute("t-key");
+    if (!shouldWarn && node.tagName === "t") {
+      if (node.hasAttribute("t-component") && !node.hasAttribute("t-key")) {
+        shouldWarn = true;
+      }
+      if (
+        !shouldWarn &&
+        node.children.length === 1 &&
+        node.children[0].tagName !== "t" &&
+        !node.children[0].hasAttribute("t-key")
+      ) {
+        shouldWarn = true;
+      }
+    }
    if (shouldWarn) {
      console.warn(
        `Directive t-foreach should always be used with a t-key! (in template: '${ctx.templateName}')`
      );
    }
-
    nodeCopy.removeAttribute("t-foreach");
    qweb._compileNode(nodeCopy, ctx);
    ctx.dedent();
@@ -1,11 +1,11 @@
-import { compileExpr, QWebVar, QWebExprVar } from "./expression_parser";
+import { compileExpr, QWebVar } from "./expression_parser";

 export const INTERP_REGEXP = /\{\{.*?\}\}/g;
 //------------------------------------------------------------------------------
 // Compilation Context
 //------------------------------------------------------------------------------

-export class CompilationContext {
+export class Context {
  nextID: number = 1;
  code: string[] = [];
  variables: { [key: string]: QWebVar } = {};
@@ -14,7 +14,7 @@ export class CompilationContext {
  parentTextNode: number | null = null;
  rootNode: number | null = null;
  indentLevel: number = 0;
-  rootContext: CompilationContext;
+  rootContext: Context;
  caller: Element | undefined;
  shouldDefineOwner: boolean = false;
  shouldDefineParent: boolean = false;
@@ -22,10 +22,9 @@ export class CompilationContext {
  shouldDefineUtils: boolean = false;
  shouldDefineRefs: boolean = false;
  shouldDefineResult: boolean = true;
-  shouldDefineSibling: boolean = true;
  shouldProtectContext: boolean = false;
  shouldTrackScope: boolean = false;
-  loopNumber: number = 0;
+  inLoop: boolean = false;
  inPreTag: boolean = false;
  templateName: string;
  allowMultipleRoots: boolean = false;
@@ -64,9 +63,6 @@ export class CompilationContext {
    if (this.shouldDefineResult) {
      this.code.unshift("    let result;");
    }
-    if (this.shouldDefineSibling) {
-      this.code.unshift("    let sibling = null;");
-    }
    if (this.shouldDefineRefs) {
      this.code.unshift("    context.__owl__.refs = context.__owl__.refs || {};");
    }
@@ -91,7 +87,7 @@ export class CompilationContext {
    return this.code;
  }

-  withParent(node: number): CompilationContext {
+  withParent(node: number): Context {
    if (
      !this.allowMultipleRoots &&
      this === this.rootContext &&
@@ -102,13 +98,13 @@ export class CompilationContext {
    if (!this.rootContext.rootNode) {
      this.rootContext.rootNode = node;
    }
-    if (!this.parentNode && this.rootContext.shouldDefineResult) {
+    if (!this.parentNode) {
      this.addLine(`result = vn${node};`);
    }
    return this.subContext("parentNode", node);
  }

-  subContext(key: keyof CompilationContext, value: any): CompilationContext {
+  subContext(key: keyof Context, value: any): Context {
    const newContext = Object.create(this);
    newContext[key] = value;
    return newContext;
@@ -149,7 +145,7 @@ export class CompilationContext {
    this.addLine("}");
  }

-  getValue(val: any): QWebExprVar | string {
+  getValue(val: any): any {
    return val in this.variables ? this.getValue(this.variables[val]) : val;
  }

@@ -40,34 +40,34 @@ QWeb.addDirective({
      extraArgs = args.slice(1, -1);
      return "";
    });
+    ctx.addIf(`!context['${handlerName}']`);
+    ctx.addLine(
+      `throw new Error('Missing handler \\'' + '${handlerName}' + \`\\' when evaluating template '${ctx.templateName.replace(
+        /`/g,
+        "'"
+      )}'\`)`
+    );
+    ctx.closeIf();
    let params = extraArgs ? `owner, ${ctx.formatExpression(extraArgs)}` : "owner";
-    let handler = `function (e) {`;
-    handler += mods
-      .map(function(mod) {
-        return MODS_CODE[mod];
-      })
-      .join("");
-    if (handlerName) {
-      if (!extraArgs) {
-        handler += `const fn = context['${handlerName}'];`;
-        handler += `if (fn) { fn.call(${params}, e); } else { context.${handlerName}; }`;
-        handler += `}`;
-        ctx.addLine(
-          `extra.handlers['${eventName}' + ${nodeID}] = extra.handlers['${eventName}' + ${nodeID}] || ${handler};`
-        );
-        ctx.addLine(`p${nodeID}.on['${eventName}'] = extra.handlers['${eventName}' + ${nodeID}];`);
-      } else {
-        const handlerKey = `handler${ctx.generateID()}`;
-        ctx.addLine(
-          `const ${handlerKey} = context['${handlerName}'] && context['${handlerName}'].bind(${params});`
-        );
-        handler += `if (${handlerKey}) { ${handlerKey}(e); } else { context.${value}; }`;
-        handler += `}`;
-        ctx.addLine(`p${nodeID}.on['${eventName}'] = ${handler};`);
-      }
+    let handler;
+    if (mods.length > 0) {
+      handler = `function (e) {`;
+      handler += mods
+        .map(function(mod) {
+          return MODS_CODE[mod];
+        })
+        .join("");
+      handler += `context['${handlerName}'].call(${params}, e);}`;
    } else {
-      handler += "}";
+      handler = `context['${handlerName}'].bind(${params})`;
+    }
+    if (extraArgs) {
      ctx.addLine(`p${nodeID}.on['${eventName}'] = ${handler};`);
+    } else {
+      ctx.addLine(
+        `extra.handlers['${eventName}' + ${nodeID}] = extra.handlers['${eventName}' + ${nodeID}] || ${handler};`
+      );
+      ctx.addLine(`p${nodeID}.on['${eventName}'] = extra.handlers['${eventName}' + ${nodeID}];`);
    }
  }
 });
@@ -83,7 +83,6 @@ QWeb.addDirective({
    const refKey = `ref${ctx.generateID()}`;
    ctx.addLine(`const ${refKey} = ${ctx.interpolate(value)};`);
    addNodeHook("create", `context.__owl__.refs[${refKey}] = n.elm;`);
-    addNodeHook("destroy", `delete context.__owl__.refs[${refKey}];`);
  }
 });

@@ -197,20 +196,9 @@ QWeb.addDirective({
      `const slot${slotKey} = this.constructor.slots[context.__owl__.slotId + '_' + '${value}'];`
    );
    ctx.addIf(`slot${slotKey}`);
-    let parentNode = `c${ctx.parentNode}`;
-    if (!ctx.parentNode) {
-      ctx.rootContext.shouldDefineResult = true;
-      ctx.rootContext.shouldDefineUtils = true;
-      parentNode = `children${ctx.nextID++}`;
-      ctx.addLine(`let ${parentNode}= []`);
-      ctx.addLine(`result = {}`);
-    }
    ctx.addLine(
-      `slot${slotKey}.call(this, context.__owl__.parent, Object.assign({}, extra, {parentNode: ${parentNode}, vars: extra.vars, parent: owner}));`
+      `slot${slotKey}.call(this, context.__owl__.parent, Object.assign({}, extra, {parentNode: c${ctx.parentNode}, vars: extra.vars, parent: owner}));`
    );
-    if (!ctx.parentNode) {
-      ctx.addLine(`utils.defineProxy(result, ${parentNode}[0]);`);
-    }
    ctx.closeIf();
    return true;
  }
@@ -261,16 +249,3 @@ QWeb.addDirective({
    ctx.addLine(`p${nodeID}.on['${event}'] = extra.handlers['${event}' + ${nodeID}];`);
  }
 });
-
-//------------------------------------------------------------------------------
-// t-key
-//------------------------------------------------------------------------------
-QWeb.addDirective({
-  name: "key",
-  priority: 45,
-  atNodeEncounter({ ctx, value }) {
-    let id = ctx.generateID();
-    ctx.addLine(`const nodeKey${id} = ${ctx.formatExpression(value)};`);
-    ctx.lastNodeKey = `nodeKey${id}`;
-  }
-});
@@ -1,6 +1,6 @@
 import { EventBus } from "../core/event_bus";
 import { h, patch, VNode } from "../vdom/index";
-import { CompilationContext } from "./compilation_context";
+import { Context } from "./context";
 import { shallowEqual } from "../utils";
 import { addNS } from "../vdom/vdom";

@@ -36,7 +36,7 @@ interface Template {
 interface CompilationInfo {
  node: Element;
  qweb: QWeb;
-  ctx: CompilationContext;
+  ctx: Context;
  fullName: string;
  value: string;
 }
@@ -57,27 +57,19 @@ export interface Directive {
  finalize?(info: CompilationInfo): void;
 }

-interface QWebConfig {
-  templates?: string;
-  translateFn?(text: string): string;
-}
-
 //------------------------------------------------------------------------------
 // Const/global stuff/helpers
 //------------------------------------------------------------------------------

 const DISABLED_TAGS = ["input", "textarea", "button", "select", "option", "optgroup"];

-const TRANSLATABLE_ATTRS = ["label", "title", "placeholder", "alt"];
-
 const lineBreakRE = /[\r\n]/;
 const whitespaceRE = /\s+/g;

 const NODE_HOOKS_PARAMS = {
  create: "(_, n)",
  insert: "vn",
-  remove: "(vn, rm)",
-  destroy: "()"
+  remove: "(vn, rm)"
 };

 interface Utils {
@@ -111,6 +103,8 @@ const UTILS: Utils = {
 function parseXML(xml: string): Document {
  const parser = new DOMParser();

+  // we remove comments from the xml string
+  xml = xml.replace(/<!--[\s\S]*?-->/g, "");
  const doc = parser.parseFromString(xml, "text/xml");
  if (doc.getElementsByTagName("parsererror").length) {
    let msg = "Invalid XML in template.";
@@ -141,7 +135,6 @@ function parseXML(xml: string): Document {
 //------------------------------------------------------------------------------
 // QWeb rendering engine
 //------------------------------------------------------------------------------
-
 export class QWeb extends EventBus {
  templates: { [name: string]: Template };
  static utils = UTILS;
@@ -151,7 +144,7 @@ export class QWeb extends EventBus {
    name: 1,
    att: 1,
    attf: 1,
-    translation: 1
+    key: 1
  };
  static DIRECTIVES: Directive[] = [];

@@ -174,16 +167,12 @@ export class QWeb extends EventBus {
  recursiveFns = {};

  isUpdating: boolean = false;
-  translateFn?: QWebConfig["translateFn"];

-  constructor(config: QWebConfig = {}) {
+  constructor(data?: string) {
    super();
    this.templates = Object.create(QWeb.TEMPLATES);
-    if (config.templates) {
-      this.addTemplates(config.templates);
-    }
-    if (config.translateFn) {
-      this.translateFn = config.translateFn;
+    if (data) {
+      this.addTemplates(data);
    }
  }

@@ -353,9 +342,9 @@ export class QWeb extends EventBus {
    });
  }

-  _compile(name: string, elem: Element, parentContext?: CompilationContext): CompiledTemplate {
+  _compile(name: string, elem: Element, parentContext?: Context): CompiledTemplate {
    const isDebug = elem.attributes.hasOwnProperty("t-debug");
-    const ctx = new CompilationContext(name);
+    const ctx = new Context(name);
    if (elem.tagName !== "t") {
      ctx.shouldDefineResult = false;
    }
@@ -420,7 +409,7 @@ export class QWeb extends EventBus {
   * Generate code from an xml node
   *
   */
-  _compileNode(node: ChildNode, ctx: CompilationContext) {
+  _compileNode(node: ChildNode, ctx: Context) {
    if (!(node instanceof Element)) {
      // this is a text node, there are no directive to apply
      let text = node.textContent!;
@@ -430,17 +419,8 @@ export class QWeb extends EventBus {
        }
        text = text.replace(whitespaceRE, " ");
      }
-      if (this.translateFn) {
-        if ((node.parentNode as any).getAttribute("t-translation") !== "off") {
-          text = this.translateFn(text);
-        }
-      }
      if (ctx.parentNode) {
-        if (node.nodeType === 3) {
-          ctx.addLine(`c${ctx.parentNode}.push({text: \`${text}\`});`);
-        } else if (node.nodeType === 8) {
-          ctx.addLine(`c${ctx.parentNode}.push(h('!', \`${text}\`));`);
-        }
+        ctx.addLine(`c${ctx.parentNode}.push({text: \`${text}\`});`);
      } else if (ctx.parentTextNode) {
        ctx.addLine(`vn${ctx.parentTextNode}.text += \`${text}\`;`);
      } else {
@@ -469,7 +449,7 @@ export class QWeb extends EventBus {
      fullName: string;
    }[] = [];

-    const finalizers: typeof validDirectives = [];
+    let withHandlers = false;

    // maybe this is not optimal: we iterate on all attributes here, and again
    // just after for each directive.
@@ -480,21 +460,11 @@ export class QWeb extends EventBus {
        if (!(dName in QWeb.DIRECTIVE_NAMES)) {
          throw new Error(`Unknown QWeb directive: '${attrName}'`);
        }
-        if (node.tagName !== "t" && (attrName === "t-esc" || attrName === "t-raw")) {
-          const tNode = document.createElement("t");
-          tNode.setAttribute(attrName, node.getAttribute(attrName)!);
-          for (let child of Array.from(node.childNodes)) {
-            tNode.appendChild(child);
-          }
-          node.appendChild(tNode);
-          node.removeAttribute(attrName);
-        }
      }
    }

    const DIR_N = QWeb.DIRECTIVES.length;
    const ATTR_N = attributes.length;
-    let withHandlers = false;
    for (let i = 0; i < DIR_N; i++) {
      let directive = QWeb.DIRECTIVES[i];
      let fullName;
@@ -515,11 +485,7 @@ export class QWeb extends EventBus {
        }
      }
    }
-
    for (let { directive, value, fullName } of validDirectives) {
-      if (directive.finalize) {
-        finalizers.push({ directive, value, fullName });
-      }
      if (directive.atNodeEncounter) {
        const isDone = directive.atNodeEncounter({
          node,
@@ -529,9 +495,6 @@ export class QWeb extends EventBus {
          value
        });
        if (isDone) {
-          for (let { directive, value, fullName } of finalizers) {
-            directive.finalize!({ node, qweb: this, ctx, fullName, value });
-          }
          return;
        }
      }
@@ -590,16 +553,14 @@ export class QWeb extends EventBus {
      ctx.addLine(`utils.addNameSpace(vn${ctx.parentNode});`);
    }

-    for (let { directive, value, fullName } of finalizers) {
-      directive.finalize!({ node, qweb: this, ctx, fullName, value });
+    for (let { directive, value, fullName } of validDirectives) {
+      if (directive.finalize) {
+        directive.finalize({ node, qweb: this, ctx, fullName, value });
+      }
    }
  }

-  _compileGenericNode(
-    node: ChildNode,
-    ctx: CompilationContext,
-    withHandlers: boolean = true
-  ): number {
+  _compileGenericNode(node: ChildNode, ctx: Context, withHandlers: boolean = true): number {
    // nodeType 1 is generic tag
    if (node.nodeType !== 1) {
      throw new Error("unsupported node type");
@@ -634,11 +595,7 @@ export class QWeb extends EventBus {

    for (let i = 0; i < attributes.length; i++) {
      let name = attributes[i].name;
-      let value = attributes[i].textContent!;
-
-      if (this.translateFn && TRANSLATABLE_ATTRS.includes(name)) {
-        value = this.translateFn(value);
-      }
+      const value = attributes[i].textContent!;

      // regular attributes
      if (!name.startsWith("t-") && !(<Element>node).getAttribute("t-attf-" + name)) {
@@ -666,7 +623,7 @@ export class QWeb extends EventBus {
      if (name.startsWith("t-att-")) {
        let attName = name.slice(6);
        const v = ctx.getValue(value);
-        let formattedValue = typeof v === "string" ? ctx.formatExpression(v) : v.id;
+        let formattedValue = v.id || ctx.formatExpression(v);

        if (attName === "class") {
          ctx.rootContext.shouldDefineUtils = true;
@@ -724,7 +681,14 @@ export class QWeb extends EventBus {
      }
    }
    let nodeID = ctx.generateID();
-    let nodeKey = ctx.lastNodeKey || nodeID;
+    let nodeKey: any = (<Element>node).getAttribute("t-key");
+    if (nodeKey) {
+      ctx.addLine(`const nodeKey${nodeID} = ${ctx.formatExpression(nodeKey)}`);
+      nodeKey = `nodeKey${nodeID}`;
+      ctx.lastNodeKey = nodeKey;
+    } else {
+      nodeKey = nodeID;
+    }
    const parts = [`key:${nodeKey}`];
    if (attrs.length + tattrs.length > 0) {
      parts.push(`attrs:{${attrs.join(",")}}`);
@@ -759,7 +723,7 @@ export class QWeb extends EventBus {
    return nodeID;
  }

-  _compileChildren(node: ChildNode, ctx: CompilationContext) {
+  _compileChildren(node: ChildNode, ctx: Context) {
    if (node.childNodes.length > 0) {
      for (let child of Array.from(node.childNodes)) {
        this._compileNode(child, ctx);
@@ -1,6 +1,6 @@
 import { Component } from "../component/component";
 import { xml } from "../tags";
-import { Destination, RouterEnv } from "./router";
+import { Destination, RouterEnv } from "./Router";

 type Props = Destination;

@@ -148,7 +148,7 @@ export class Router {
  //--------------------------------------------------------------------------

  private setUrlFromPath(path: string) {
-    const separator = this.mode === "hash" ? location.pathname : "";
+    const separator = this.mode === "hash" ? "/" : "";
    const url = location.origin + separator + path;
    if (url !== window.location.href) {
      window.history.pushState({}, path, url);
@@ -1,141 +0,0 @@
-import { Component } from "./component/component";
-import { Env } from "./component/component";
-import { Context, useContextWithCB } from "./context";
-import { onWillUpdateProps } from "./hooks";
-
-/**
- * Owl Store
- *
- * We have here:
- * - a Store class
- * - useStore hook
- * - useDispatch hook
- * - useGetters hook
- *
- * The Owl store is our answer to the problem of managing complex state across
- * components. The main idea is that the store owns some state, allow external
- * code to modify it through actions, and for each state changes,
- * connected component will be notified, and updated if necessary.
- *
- * Note that this code is partly inspired by VueX and React/Redux
- */
-
-//------------------------------------------------------------------------------
-// Store Definition
-//------------------------------------------------------------------------------
-
-export type Action = ({ state, dispatch, env, getters }, ...payload: any) => any;
-export type Getter = ({ state: any, getters }, payload?) => any;
-
-interface StoreConfig {
-  env?: Env;
-  state?: any;
-  actions?: { [name: string]: Action };
-  getters?: { [name: string]: Getter };
-}
-
-export class Store extends Context {
-  actions: any;
-  env: any;
-  getters: { [name: string]: (payload?) => any };
-  updateFunctions: { [key: number]: (() => boolean)[] };
-
-  constructor(config: StoreConfig) {
-    super(config.state);
-    this.actions = config.actions;
-    this.env = config.env;
-    this.getters = {};
-    this.updateFunctions = [];
-    if (config.getters) {
-      const firstArg = {
-        state: this.state,
-        getters: this.getters
-      };
-      for (let g in config.getters) {
-        this.getters[g] = config.getters[g].bind(this, firstArg);
-      }
-    }
-  }
-
-  dispatch(action: string, ...payload: any): Promise<void> | void {
-    if (!this.actions[action]) {
-      throw new Error(`[Error] action ${action} is undefined`);
-    }
-    const result = this.actions[action](
-      {
-        dispatch: this.dispatch.bind(this),
-        env: this.env,
-        state: this.state,
-        getters: this.getters
-      },
-      ...payload
-    );
-    return result;
-  }
-}
-
-interface SelectorOptions {
-  store?: Store;
-  isEqual?: (a: any, b: any) => boolean;
-}
-
-const isStrictEqual = (a, b) => a === b;
-
-export function useStore(selector, options: SelectorOptions = {}): any {
-  const component: Component<any, any> = Component.current!;
-  const store = options.store || (component.env.store as Store);
-  let result = selector(store.state, component.props);
-  const hashFn = store.observer.revNumber.bind(store.observer);
-  let revNumber = hashFn(result) || result;
-  const isEqual = options.isEqual || isStrictEqual;
-  if (!store.updateFunctions[component.__owl__.id]) {
-    store.updateFunctions[component.__owl__.id] = [];
-  }
-  const updateFunctions = store.updateFunctions[component.__owl__.id];
-  updateFunctions.push(function(): boolean {
-    const oldResult = result;
-    result = selector(store!.state, component.props);
-    const newRevNumber = hashFn(result);
-    if (
-      (newRevNumber > 0 && revNumber !== newRevNumber) ||
-      (newRevNumber === 0 && !isEqual(oldResult, result))
-    ) {
-      revNumber = newRevNumber;
-      return true;
-    }
-    return false;
-  });
-
-  useContextWithCB(store, component, function(): Promise<void> | void {
-    let shouldRender = false;
-    updateFunctions.forEach(function(updateFn) {
-      shouldRender = updateFn() || shouldRender;
-    });
-    if (shouldRender) {
-      return component.render();
-    }
-  });
-  onWillUpdateProps(props => {
-    delete store.updateFunctions[component.__owl__.id];
-    result = selector(store.state, props);
-  });
-  return new Proxy(result, {
-    get(target, k) {
-      return result[k];
-    },
-    set(target, k, v) {
-      result[k] = v;
-      return true;
-    }
-  });
-}
-
-export function useDispatch(store?: Store): Store["dispatch"] {
-  store = store || (Component.current!.env.store as Store);
-  return store.dispatch.bind(store);
-}
-
-export function useGetters(store?: Store): Store["getters"] {
-  store = store || (Component.current!.env.store as Store);
-  return store.getters;
-}
@@ -0,0 +1,147 @@
+import { Component, Env, Fiber } from "../component/component";
+import { VNode } from "../vdom/index";
+
+//------------------------------------------------------------------------------
+// Connect function
+//------------------------------------------------------------------------------
+
+type HashFunction = (a: any, b: any) => number;
+
+export class ConnectedComponent<T extends Env, P> extends Component<T, P> {
+  deep: boolean = true;
+  getStore(env) {
+    return env.store;
+  }
+
+  storeProps: any;
+
+  hashFunction: HashFunction = (storeProps, options) => {
+    const revFn = (this.__owl__ as any).revFn;
+    const rev = revFn(storeProps);
+    if (rev > 0) {
+      return rev;
+    }
+    let hash = 0;
+    for (let key in storeProps) {
+      const val = storeProps[key];
+      const hashVal = revFn(val);
+      if (hashVal === 0) {
+        if (val !== options.prevStoreProps[key]) {
+          options.didChange = true;
+        }
+      } else {
+        hash += hashVal;
+      }
+    }
+    return hash;
+  };
+
+  static mapStoreToProps(storeState, ownProps, getters) {
+    return {};
+  }
+
+  dispatch(name, ...payload) {
+    return (this.__owl__ as any).store.dispatch(name, ...payload);
+  }
+
+  /**
+   * Need to do this here so 'deep' can be overrided by subcomponent easily
+   */
+  async __prepareAndRender(fiber: Fiber<P>): Promise<VNode> {
+    const store = this.getStore(this.env);
+    const ownProps = this.props || {};
+    this.storeProps = (<any>this.constructor).mapStoreToProps(store.state, ownProps, store.getters);
+    const observer = store.observer;
+    const revFn = this.deep ? observer.deepRevNumber : observer.revNumber;
+    (this.__owl__ as any).store = store;
+    (this.__owl__ as any).ownProps = this.props;
+    (this.__owl__ as any).revFn = revFn.bind(observer);
+    (this.__owl__ as any).storeHash = this.hashFunction(this.storeProps, {
+      prevStoreProps: this.storeProps
+    });
+    (this.__owl__ as any).rev = observer.rev;
+    return super.__prepareAndRender(fiber);
+  }
+  /**
+   * We do not use the mounted hook here for a subtle reason: we want the
+   * updates to be called for the parents before the children.  However,
+   * if we use the mounted hook, this will be done in the reverse order.
+   */
+  __callMounted() {
+    (this.__owl__ as any).store.on("update", this, this.__checkUpdate);
+    super.__callMounted();
+  }
+  __callWillUnmount() {
+    (this.__owl__ as any).store.off("update", this);
+    super.__callWillUnmount();
+  }
+  __destroy(parent: any) {
+    (this.__owl__ as any).store.off("update", this);
+    super.__destroy(parent);
+  }
+
+  async render(force: boolean = false) {
+    this.__updateStoreProps(this.props);
+
+    // this is quite technical, so this deserves some explanation.
+    // When we have a connected component, it can be updated for 3 reasons:
+    // - some internal state changes (this will go through this method)
+    // - some props changes (if a parent is changed and need to rerender itself)
+    // - a store update
+    //
+    // It is possible (with connected component and parent) to have the following
+    // situation: the parent component is rendered first (from its state change),
+    // then immediately after, it is rendered (from store update). Then, if the
+    // __checkUpdate method is immediately over, the children component will
+    // be rendered again by the store update, even though it is supposed to be
+    // destroyed by the first rendering.
+    //
+    // So, the solution is to keep the information that there is a current
+    // rendering occuring with the same store state, the same props, and return
+    // that in the __checkUpdate method.  To do this, we use the renderPromise
+    // deferred, which is not used by the component system once the
+    // component is ready, so we can use it for our own purpose.
+    (this.__owl__ as any).renderPromise = super.render(force);
+    return (this.__owl__ as any).renderPromise;
+  }
+
+  async __updateProps(nextProps: P, f, s, v) {
+    this.__updateStoreProps(nextProps);
+    return super.__updateProps(nextProps, f, s, v);
+  }
+
+  __updateStoreProps(nextProps): boolean {
+    const __owl__ = this.__owl__ as any;
+    const store = __owl__.store;
+    const observer = store.observer;
+    if (observer.rev === __owl__.rev && nextProps === __owl__.ownProps) {
+      return false;
+    }
+
+    const storeProps = (<any>this.constructor).mapStoreToProps(
+      store.state,
+      nextProps,
+      store.getters
+    );
+    const options = { prevStoreProps: this.storeProps, didChange: false };
+    const storeHash = this.hashFunction(storeProps, options);
+    this.storeProps = storeProps;
+    let didChange = options.didChange;
+    if (storeHash !== __owl__.storeHash) {
+      __owl__.storeHash = storeHash;
+      didChange = true;
+    }
+    __owl__.rev = store.observer.rev;
+    __owl__.ownProps = nextProps;
+    return didChange;
+  }
+
+  async __checkUpdate() {
+    const didChange = this.__updateStoreProps(this.props);
+    if (didChange) {
+      return this.render();
+    }
+    // see note in render method
+    return (this.__owl__ as any).renderPromise;
+  }
+}
@@ -0,0 +1,107 @@
+import { Env } from "../component/component";
+import { EventBus } from "../core/event_bus";
+import { Observer } from "../core/observer";
+
+/**
+ * Owl Store
+ *
+ * We have here:
+ * - a Store class
+ * - the ConnectedComponent class
+ *
+ * The Owl store is our answer to the problem of managing complex state across
+ * components. The main idea is that the store owns some state, allow external
+ * code to modify it through actions, and for each state changes,
+ * connected component will be notified, and updated if necessary.
+ *
+ * Note that this code is partly inspired by VueX and React/Redux
+ */
+
+//------------------------------------------------------------------------------
+// Store Definition
+//------------------------------------------------------------------------------
+
+export type Action = ({ state, dispatch, env, getters }, ...payload: any) => any;
+export type Getter = ({ state: any, getters }, payload?) => any;
+
+interface StoreConfig {
+  env?: Env;
+  state?: any;
+  actions?: { [name: string]: Action };
+  getters?: { [name: string]: Getter };
+}
+
+interface StoreOption {
+  debug?: boolean;
+}
+
+export class Store extends EventBus {
+  state: any;
+  actions: any;
+  mutations: any;
+  debug: boolean;
+  env: any;
+  observer: Observer;
+  getters: { [name: string]: (payload?) => any };
+
+  constructor(config: StoreConfig, options: StoreOption = {}) {
+    super();
+    this.debug = options.debug || false;
+    this.actions = config.actions;
+    this.env = config.env;
+    this.observer = new Observer();
+    this.observer.notifyCB = this.__notifyComponents.bind(this);
+    this.state = this.observer.observe(config.state || {});
+    this.getters = {};
+    if (config.getters) {
+      const firstArg = {
+        state: this.state,
+        getters: this.getters
+      };
+      for (let g in config.getters) {
+        this.getters[g] = config.getters[g].bind(this, firstArg);
+      }
+    }
+  }
+
+  dispatch(action: string, ...payload: any): Promise<void> | void {
+    if (!this.actions[action]) {
+      throw new Error(`[Error] action ${action} is undefined`);
+    }
+    const result = this.actions[action](
+      {
+        dispatch: this.dispatch.bind(this),
+        env: this.env,
+        state: this.state,
+        getters: this.getters
+      },
+      ...payload
+    );
+    return result;
+  }
+
+  /**
+   * Instead of using trigger to emit an update event, we actually implement
+   * our own function to do that.  The reason is that we need to be smarter than
+   * a simple trigger function: we need to wait for parent components to be
+   * done before doing children components.  The reason is that if an update
+   * as an effect of destroying a children, we do not want to call the
+   * mapStoreToProps function of the child, nor rendering it.
+   *
+   * This method is not optimal if we have a bunch of asynchronous components:
+   * we wait sequentially for each component to be completed before updating the
+   * next.  However, the only things that matters is that children are updated
+   * after their parents.  So, this could be optimized by being smarter, and
+   * updating all widgets concurrently, except for parents/children.
+   */
+  async __notifyComponents() {
+    const subs = this.subscriptions.update || [];
+    for (let i = 0, iLen = subs.length; i < iLen; i++) {
+      const sub = subs[i];
+      const shouldCallback = sub.owner ? sub.owner.__owl__.isMounted : true;
+      if (shouldCallback) {
+        await sub.callback.call(sub.owner);
+      }
+    }
+  }
+}
@@ -5,7 +5,7 @@
 *
 * - whenReady
 * - loadJS
- * - loadFile
+ * - loadTemplates
 * - escape
 * - debounce
 */
@@ -43,7 +43,7 @@ export function loadJS(url: string): Promise<void> {
  return promise;
 }

-export async function loadFile(url: string): Promise<string> {
+export async function loadTemplates(url: string): Promise<string> {
  const result = await fetch(url);
  if (!result.ok) {
    throw new Error("Error while fetching xml templates");
@@ -1,29 +0,0 @@
-import { VNode, h } from "./vdom";
-
-const parser = new DOMParser();
-
-export function htmlToVDOM(html: string): VNode[] {
-  const doc = parser.parseFromString(html, "text/html");
-  const result: VNode[] = [];
-  for (let child of doc.body.childNodes) {
-    result.push(htmlToVNode(child));
-  }
-  return result;
-}
-
-function htmlToVNode(node: ChildNode): VNode {
-  if (!(node instanceof Element)) {
-    return { text: node.textContent! } as VNode;
-  }
-  const attrs = {};
-  for (let attr of node.attributes) {
-    attrs[attr.name] = attr.textContent;
-  }
-  const children: VNode[] = [];
-  if (node.hasChildNodes) {
-    for (let c of node.childNodes) {
-      children.push(htmlToVNode(c));
-    }
-  }
-  return h((node as Element).tagName, { attrs }, children);
-}
@@ -176,10 +176,18 @@ export function init(modules: Array<Partial<Module>>, domApi?: DOMAPI) {
      }
      vnode.elm = api.createComment(vnode.text as string);
    } else if (sel !== undefined) {
+      // Parse selector
+      const hashIdx = sel.indexOf("#");
+      const dotIdx = sel.indexOf(".", hashIdx);
+      const hash = hashIdx > 0 ? hashIdx : sel.length;
+      const dot = dotIdx > 0 ? dotIdx : sel.length;
+      const tag = hashIdx !== -1 || dotIdx !== -1 ? sel.slice(0, Math.min(hash, dot)) : sel;
      const elm = (vnode.elm =
        isDef(data) && isDef((i = (data as VNodeData).ns))
-          ? api.createElementNS(i, sel)
-          : api.createElement(sel));
+          ? api.createElementNS(i, tag)
+          : api.createElement(tag));
+      if (hash < dot) elm.setAttribute("id", sel.slice(hash + 1, dot));
+      if (dotIdx > 0) elm.setAttribute("class", sel.slice(dot + 1).replace(/\./g, " "));
      for (i = 0, iLen = cbs.create.length; i < iLen; ++i) cbs.create[i](emptyNode, vnode);
      if (array(children)) {
        for (i = 0, iLen = children.length; i < iLen; ++i) {
@@ -557,15 +565,13 @@ type ArrayOrElement<T> = T | T[];
 type VNodeChildren = ArrayOrElement<VNodeChildElement>;

 export function addNS(data: any, children: VNodes | undefined, sel: string | undefined): void {
-  if (sel === "dummy") {
-    // we do not need to add the namespace on dummy elements, they come from a
-    // subcomponent, which will handle the namespace itself
-    return;
-  }
  data.ns = "http://www.w3.org/2000/svg";
  if (sel !== "foreignObject" && children !== undefined) {
    for (let i = 0, iLen = children.length; i < iLen; ++i) {
      const child = children[i];
+      if (child === null) {
+        continue;
+      }
      let childData = child.data;
      if (childData !== undefined) {
        addNS(childData, (child as VNode).children as VNodes, child.sel);
@@ -7,39 +7,40 @@ exports[`animations t-transition combined with component 1`] = `
    let QWeb = this.constructor;
    let parent = context;
    let owner = context;
-    let sibling = null;
    var h = this.h;
    let c1 = [], p1 = {key:1};
    var vn1 = h('div', p1, c1);
+    result = vn1;
    //COMPONENT
-    let templateId3 = \`__4__\`;
-    let w3 = templateId3 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[templateId3]] : false;
-    let props3 = {};
-    if (w3 && w3.__owl__.currentFiber && !w3.__owl__.vnode) {
-        w3.destroy();
-        w3 = false;
+    let def3;
+    let w4 = 4 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[4]] : false;
+    let _2_index = c1.length;
+    c1.push(null);
+    let props4 = {};
+    if (w4 && w4.__owl__.currentFiber && !w4.__owl__.vnode) {
+        if (utils.shallowEqual(props4, w4.__owl__.currentFiber.props)) {
+            def3 = w4.__owl__.currentFiber.promise;
+        } else {
+            w4.destroy();
+            w4 = false;
+        }
    }
-    if (w3) {
-        w3.__updateProps(props3, extra.fiber, undefined, undefined, sibling);
-        let pvnode = w3.__owl__.pvnode;
-        c1.push(pvnode);
-    } else {
-        let componentKey3 = \`Child\`;
-        let W3 = context.constructor.components[componentKey3] || QWeb.components[componentKey3]|| context['Child'];
-        if (!W3) {throw new Error('Cannot find the definition of component \\"' + componentKey3 + '\\"')}
-        w3 = new W3(parent, props3);
-        parent.__owl__.cmap[templateId3] = w3.__owl__.id;
-        let def2 = w3.__prepare(extra.fiber, undefined, undefined, sibling);
-        let pvnode = h('dummy', {key: templateId3, hook: {insert(vn) { let nvn=w3.__mount(fiber, pvnode.elm);pvnode.elm=nvn.elm;utils.transitionInsert(vn, 'chimay');},remove() {},destroy(vn) {let finalize = () => {
-          w3.destroy();
+    if (!w4) {
+        let componentKey4 = \`Child\`;
+        let W4 = context.constructor.components[componentKey4] || QWeb.components[componentKey4]|| context['Child'];
+        if (!W4) {throw new Error('Cannot find the definition of component \\"' + componentKey4 + '\\"')}
+        w4 = new W4(parent, props4);
+        parent.__owl__.cmap[4] = w4.__owl__.id;
+        def3 = w4.__prepare(extra.fiber, undefined, undefined);
+        def3 = def3.then(vnode=>{if (w4.__owl__.isDestroyed){return}let pvnode=h(vnode.sel, {key: 4, hook: {insert(vn) {let nvn=w4.__mount(vnode, pvnode.elm);pvnode.elm=nvn.elm;utils.transitionInsert(vn, 'chimay');},remove() {},destroy(vn) {let finalize = () => {
+          w4.destroy();
        };
-        utils.transitionRemove(vn, 'chimay', finalize);}}});
-        const fiber = w3.__owl__.currentFiber;
-        def2.then(function () {if (w3.__owl__.isDestroyed) {return;} const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
-        c1.push(pvnode);
-        w3.__owl__.pvnode = pvnode;
+        utils.transitionRemove(vn, 'chimay', finalize);}}});c1[_2_index]=pvnode;w4.__owl__.pvnode = pvnode;});
+    } else {
+        def3 = def3 || w4.__updateProps(props4, extra.fiber, undefined, undefined);
+        def3 = def3.then(()=>{if (w4.__owl__.isDestroyed) {return};let pvnode=w4.__owl__.pvnode;c1[_2_index]=pvnode;});
    }
-    sibling = w3.__owl__.currentFiber || sibling;
+    extra.promises.push(def3);
    return vn1;
 }"
 `;
@@ -51,40 +52,41 @@ exports[`animations t-transition combined with t-component and t-if 1`] = `
    let QWeb = this.constructor;
    let parent = context;
    let owner = context;
-    let sibling = null;
    var h = this.h;
    let c1 = [], p1 = {key:1};
    var vn1 = h('div', p1, c1);
+    result = vn1;
    if (context['state'].display) {
        //COMPONENT
-        let templateId3 = \`__4__\`;
-        let w3 = templateId3 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[templateId3]] : false;
-        let props3 = {};
-        if (w3 && w3.__owl__.currentFiber && !w3.__owl__.vnode) {
-            w3.destroy();
-            w3 = false;
+        let def3;
+        let w4 = 4 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[4]] : false;
+        let _2_index = c1.length;
+        c1.push(null);
+        let props4 = {};
+        if (w4 && w4.__owl__.currentFiber && !w4.__owl__.vnode) {
+            if (utils.shallowEqual(props4, w4.__owl__.currentFiber.props)) {
+                def3 = w4.__owl__.currentFiber.promise;
+            } else {
+                w4.destroy();
+                w4 = false;
+            }
        }
-        if (w3) {
-            w3.__updateProps(props3, extra.fiber, undefined, undefined, sibling);
-            let pvnode = w3.__owl__.pvnode;
-            c1.push(pvnode);
-        } else {
-            let componentKey3 = \`Child\`;
-            let W3 = context.constructor.components[componentKey3] || QWeb.components[componentKey3]|| context['Child'];
-            if (!W3) {throw new Error('Cannot find the definition of component \\"' + componentKey3 + '\\"')}
-            w3 = new W3(parent, props3);
-            parent.__owl__.cmap[templateId3] = w3.__owl__.id;
-            let def2 = w3.__prepare(extra.fiber, undefined, undefined, sibling);
-            let pvnode = h('dummy', {key: templateId3, hook: {insert(vn) { let nvn=w3.__mount(fiber, pvnode.elm);pvnode.elm=nvn.elm;utils.transitionInsert(vn, 'chimay');},remove() {},destroy(vn) {let finalize = () => {
-          w3.destroy();
+        if (!w4) {
+            let componentKey4 = \`Child\`;
+            let W4 = context.constructor.components[componentKey4] || QWeb.components[componentKey4]|| context['Child'];
+            if (!W4) {throw new Error('Cannot find the definition of component \\"' + componentKey4 + '\\"')}
+            w4 = new W4(parent, props4);
+            parent.__owl__.cmap[4] = w4.__owl__.id;
+            def3 = w4.__prepare(extra.fiber, undefined, undefined);
+            def3 = def3.then(vnode=>{if (w4.__owl__.isDestroyed){return}let pvnode=h(vnode.sel, {key: 4, hook: {insert(vn) {let nvn=w4.__mount(vnode, pvnode.elm);pvnode.elm=nvn.elm;utils.transitionInsert(vn, 'chimay');},remove() {},destroy(vn) {let finalize = () => {
+          w4.destroy();
        };
-        utils.transitionRemove(vn, 'chimay', finalize);}}});
-            const fiber = w3.__owl__.currentFiber;
-            def2.then(function () {if (w3.__owl__.isDestroyed) {return;} const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
-            c1.push(pvnode);
-            w3.__owl__.pvnode = pvnode;
+        utils.transitionRemove(vn, 'chimay', finalize);}}});c1[_2_index]=pvnode;w4.__owl__.pvnode = pvnode;});
+        } else {
+            def3 = def3 || w4.__updateProps(props4, extra.fiber, undefined, undefined);
+            def3 = def3.then(()=>{if (w4.__owl__.isDestroyed) {return};let pvnode=w4.__owl__.pvnode;c1[_2_index]=pvnode;});
        }
-        sibling = w3.__owl__.currentFiber || sibling;
+        extra.promises.push(def3);
    }
    return vn1;
 }"
@@ -94,10 +96,10 @@ exports[`animations t-transition with no delay/duration 1`] = `
 "function anonymous(context,extra
 ) {
    let utils = this.constructor.utils;
-    let sibling = null;
    var h = this.h;
    let c1 = [], p1 = {key:1};
    var vn1 = h('span', p1, c1);
+    result = vn1;
    p1.hook = {
      insert: vn => {
        utils.transitionInsert(vn, 'jupiler');
@@ -115,10 +117,10 @@ exports[`animations t-transition, on a simple node (insert) 1`] = `
 "function anonymous(context,extra
 ) {
    let utils = this.constructor.utils;
-    let sibling = null;
    var h = this.h;
    let c1 = [], p1 = {key:1};
    var vn1 = h('span', p1, c1);
+    result = vn1;
    p1.hook = {
      insert: vn => {
        utils.transitionInsert(vn, 'chimay');
@@ -1,5 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`various scenarios scenarios with async store updates and some components events 1`] = `"<div><button>Do stuff</button><div><span>Attachment 100</span><span>Name: text.txt</span></div></div>"`;
-
-exports[`various scenarios scenarios with async store updates and some components events 2`] = `"<div><button>Do stuff</button></div>"`;
@@ -1,5 +1,4 @@
 import { Component, Env } from "../src/component/component";
-import { config } from "../src/config";
 import { QWeb } from "../src/qweb/index";
 import { useState, useRef } from "../src/hooks";
 import {
@@ -30,7 +29,6 @@ let cssEl: HTMLElement;
 beforeEach(() => {
  fixture = makeTestFixture();
  env = makeTestEnv();
-  config.env = env;
  qweb = new QWeb();
 });

@@ -110,7 +108,7 @@ describe("animations", () => {
    class TestWidget extends Widget {
      state = useState({ hide: false });
    }
-    const widget = new TestWidget();
+    const widget = new TestWidget(env);

    // insert widget into the DOM
    let def = makeDeferred();
@@ -153,7 +151,7 @@ describe("animations", () => {
      state = useState({ hide: false });
      span = useRef("span");
    }
-    const widget = new TestWidget();
+    const widget = new TestWidget(env);

    // insert widget into the DOM
    let def = makeDeferred();
@@ -182,7 +180,7 @@ describe("animations", () => {
    class Parent extends Widget {
      static components = { Child: Child };
    }
-    const widget = new Parent();
+    const widget = new Parent(env);

    let def = makeDeferred();
    var spanNode;
@@ -222,7 +220,7 @@ describe("animations", () => {
      static components = { Child: Child };
      state = useState({ display: true });
    }
-    const widget = new Parent();
+    const widget = new Parent(env);

    let def = makeDeferred();
    var spanNode;
@@ -253,11 +251,11 @@ describe("animations", () => {
    widget.state.display = false;
    patchNextFrame(cb => {
      expect(fixture.innerHTML).toBe(
-        '<div><span class="chimay-leave chimay-leave-active" data-owl-key="__4__">blue</span></div>'
+        '<div><span class="chimay-leave chimay-leave-active" data-owl-key="4">blue</span></div>'
      );
      cb();
      expect(fixture.innerHTML).toBe(
-        '<div><span class="chimay-leave-active chimay-leave-to" data-owl-key="__4__">blue</span></div>'
+        '<div><span class="chimay-leave-active chimay-leave-to" data-owl-key="4">blue</span></div>'
      );
      def.resolve();
    });
@@ -285,7 +283,7 @@ describe("animations", () => {
      }
    }

-    const widget = new Parent();
+    const widget = new Parent(env);
    await widget.mount(fixture);
    let button = widget.el!.querySelector("button");

@@ -343,7 +341,7 @@ describe("animations", () => {
      }
    }

-    const widget = new Parent();
+    const widget = new Parent(env);
    await widget.mount(fixture);
    let button = widget.el!.querySelector("button");

@@ -1,5 +1,9 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP

+exports[`default props default values are also set whenever component is updated 1`] = `"<div>1</div>"`;
+
+exports[`default props default values are also set whenever component is updated 2`] = `"<div>4</div>"`;
+
 exports[`props validation props are validated in dev mode (code snapshot) 1`] = `
 "function anonymous(context,extra
 ) {
@@ -7,36 +11,39 @@ exports[`props validation props are validated in dev mode (code snapshot) 1`] =
    let QWeb = this.constructor;
    let parent = context;
    let owner = context;
-    let sibling = null;
    var h = this.h;
    let c1 = [], p1 = {key:1};
    var vn1 = h('div', p1, c1);
+    result = vn1;
    //COMPONENT
-    let templateId3 = \`__4__\`;
-    let w3 = templateId3 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[templateId3]] : false;
-    let props3 = {message:1};
-    if (w3 && w3.__owl__.currentFiber && !w3.__owl__.vnode) {
-        w3.destroy();
-        w3 = false;
+    let def3;
+    let w4 = 4 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[4]] : false;
+    let _2_index = c1.length;
+    c1.push(null);
+    let props4 = {message:1};
+    if (w4 && w4.__owl__.currentFiber && !w4.__owl__.vnode) {
+        if (utils.shallowEqual(props4, w4.__owl__.currentFiber.props)) {
+            def3 = w4.__owl__.currentFiber.promise;
+        } else {
+            w4.destroy();
+            w4 = false;
+        }
    }
-    if (w3) {
-        w3.__updateProps(props3, extra.fiber, undefined, undefined, sibling);
-        let pvnode = w3.__owl__.pvnode;
-        c1.push(pvnode);
+    if (!w4) {
+        let componentKey4 = \`Child\`;
+        let W4 = context.constructor.components[componentKey4] || QWeb.components[componentKey4]|| context['Child'];
+        if (!W4) {throw new Error('Cannot find the definition of component \\"' + componentKey4 + '\\"')}
+        utils.validateProps(W4, props4)
+        w4 = new W4(parent, props4);
+        parent.__owl__.cmap[4] = w4.__owl__.id;
+        def3 = w4.__prepare(extra.fiber, undefined, undefined);
+        def3 = def3.then(vnode=>{if (w4.__owl__.isDestroyed){return}let pvnode=h(vnode.sel, {key: 4, hook: {insert(vn) {let nvn=w4.__mount(vnode, pvnode.elm);pvnode.elm=nvn.elm;},remove() {},destroy(vn) {w4.destroy();}}});c1[_2_index]=pvnode;w4.__owl__.pvnode = pvnode;});
    } else {
-        let componentKey3 = \`Child\`;
-        let W3 = context.constructor.components[componentKey3] || QWeb.components[componentKey3]|| context['Child'];
-        if (!W3) {throw new Error('Cannot find the definition of component \\"' + componentKey3 + '\\"')}
-        w3 = new W3(parent, props3);
-        parent.__owl__.cmap[templateId3] = w3.__owl__.id;
-        let def2 = w3.__prepare(extra.fiber, undefined, undefined, sibling);
-        let pvnode = h('dummy', {key: templateId3, hook: {insert(vn) { let nvn=w3.__mount(fiber, pvnode.elm);pvnode.elm=nvn.elm;},remove() {},destroy(vn) {w3.destroy();}}});
-        const fiber = w3.__owl__.currentFiber;
-        def2.then(function () {if (w3.__owl__.isDestroyed) {return;} const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
-        c1.push(pvnode);
-        w3.__owl__.pvnode = pvnode;
+        utils.validateProps(w4.constructor, props4)
+        def3 = def3 || w4.__updateProps(props4, extra.fiber, undefined, undefined);
+        def3 = def3.then(()=>{if (w4.__owl__.isDestroyed) {return};let pvnode=w4.__owl__.pvnode;c1[_2_index]=pvnode;});
    }
-    sibling = w3.__owl__.currentFiber || sibling;
+    extra.promises.push(def3);
    return vn1;
 }"
 `;
@@ -1,9 +1,6 @@
 import { Component, Env } from "../../src/component/component";
-import { makeTestFixture, makeTestEnv, nextTick } from "../helpers";
-import { useState } from "../../src/hooks";
-import { config } from "../../src/config";
+import { makeTestFixture, makeTestEnv } from "../helpers";
 import { QWeb } from "../../src/qweb";
-import { xml } from "../../src/tags";

 //------------------------------------------------------------------------------
 // Setup and helpers
@@ -16,7 +13,6 @@ let dev: boolean = false;
 beforeEach(() => {
  fixture = makeTestFixture();
  env = makeTestEnv();
-  config.env = env;
  dev = QWeb.dev;
  QWeb.dev = true;
 });
@@ -35,55 +31,28 @@ describe("props validation", () => {
  test("validation is only done in dev mode", async () => {
    class TestWidget extends Widget {
      static props = ["message"];
-      static template = xml`<div>hey</div>`;
-    }
-    class Parent extends Widget {
-      static components = { TestWidget };
-      static template = xml`<div><TestWidget /></div>`;
    }

-    let error;
    QWeb.dev = true;
-    try {
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeDefined();
-    expect(error.message).toBe(`Missing props 'message' (component 'TestWidget')`);
-
-    error = undefined;
+    expect(() => {
+      new TestWidget(env);
+    }).toThrow();

    QWeb.dev = false;
-    try {
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
+
+    expect(() => {
+      new TestWidget(env);
+    }).not.toThrow();
  });

  test("props: list of strings", async () => {
    class TestWidget extends Widget {
      static props = ["message"];
-      static template = xml`<div>hey</div>`;
-    }
-    class Parent extends Widget {
-      static components = { TestWidget };
-      static template = xml`<div><TestWidget /></div>`;
    }

-    let error;
-    try {
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeDefined();
-    expect(error.message).toBe(`Missing props 'message' (component 'TestWidget')`);
+    expect(() => {
+      new TestWidget(env);
+    }).toThrow("Missing props 'message' (component 'TestWidget')");
  });

  test("validate simple types", async () => {
@@ -96,50 +65,22 @@ describe("props validation", () => {
      { type: Function, ok: () => {}, ko: "1" }
    ];

-    let props;
-    class Parent extends Component<any, any> {
-      static template = xml`<div><TestWidget p="p"/></div>`;
-      get p() {
-        return props.p;
-      }
-    }
    for (let test of Tests) {
      let TestWidget = class extends Widget {
-        static template = xml`<div>hey</div>`;
        static props = { p: test.type };
      };
-      Parent.components = { TestWidget };

-      let error;
-      props = {};
-      try {
-        const p = new Parent();
-        await p.mount(fixture);
-      } catch (e) {
-        error = e;
-      }
-      expect(error).toBeDefined();
-      expect(error.message).toBe(`Missing props 'p' (component '_a')`);
+      expect(() => {
+        new TestWidget(env);
+      }).toThrow("Missing props 'p'");

-      error = undefined;
-      props = {p: test.ok};
-      try {
-        const p = new Parent();
-        await p.mount(fixture);
-      } catch (e) {
-        error = e;
-      }
-      expect(error).toBeUndefined();
+      expect(() => {
+        new TestWidget(env, { p: test.ok });
+      }).not.toThrow();

-      props = {p: test.ko};
-      try {
-        const p = new Parent();
-        await p.mount(fixture);
-      } catch (e) {
-        error = e;
-      }
-      expect(error).toBeDefined();
-      expect(error.message).toBe(`Props 'p' of invalid type in component '_a'`);
+      expect(() => {
+        new TestWidget(env, { p: test.ko });
+      }).toThrow("Props 'p' of invalid type in component");
    }
  });

@@ -153,306 +94,113 @@ describe("props validation", () => {
      { type: Function, ok: () => {}, ko: "1" }
    ];

-    let props;
-    class Parent extends Component<any, any> {
-      static template = xml`<div><TestWidget p="p"/></div>`;
-      get p() {
-        return props.p;
-      }
-    }
    for (let test of Tests) {
-      let TestWidget = class extends Component<any, any> {
+      let TestWidget = class extends Widget {
        static props = { p: { type: test.type } };
-        static template = xml`<div>hey</div>`;
      };
-      Parent.components = { TestWidget };

-      let error;
-      props = {};
-      try {
-        const p = new Parent();
-        await p.mount(fixture);
-      } catch (e) {
-        error = e;
-      }
-      expect(error).toBeDefined();
-      expect(error.message).toBe(`Missing props 'p' (component '_a')`);
+      expect(() => {
+        new TestWidget(env);
+      }).toThrow("Missing props 'p'");

-      error = undefined;
-      props = {p: test.ok};
-      try {
-        const p = new Parent();
-        await p.mount(fixture);
-      } catch (e) {
-        error = e;
-      }
-      expect(error).toBeUndefined();
+      expect(() => {
+        new TestWidget(env, { p: test.ok });
+      }).not.toThrow();

-      props = {p: test.ko};
-      try {
-        const p = new Parent();
-        await p.mount(fixture);
-      } catch (e) {
-        error = e;
-      }
-      expect(error).toBeDefined();
-      expect(error.message).toBe(`Props 'p' of invalid type in component '_a'`);
+      expect(() => {
+        new TestWidget(env, { p: test.ko });
+      }).toThrow("Props 'p' of invalid type in component");
    }
  });

  test("can validate a prop with multiple types", async () => {
-    class TestWidget extends Component<any, any> {
-      static template = xml`<div>hey</div>`;
+    let TestWidget = class extends Widget {
      static props = { p: [String, Boolean] };
    };
-    class Parent extends Component<any, any> {
-      static template = xml`<div><TestWidget p="p"/></div>`;
-      static components = { TestWidget };
-      get p() {
-        return props.p;
-      }
-    };

-    let error;
-    let props;
-    try {
-      props = { p: "string" };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
+    expect(() => {
+      new TestWidget(env, { p: "string" });
+      new TestWidget(env, { p: true });
+    }).not.toThrow();

-    try {
-      props = { p: true };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
-
-    try {
-      props = { p: 1 };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeDefined();
-    expect(error.message).toBe(`Props 'p' of invalid type in component 'TestWidget'`);
+    expect(() => {
+      new TestWidget(env, { p: 1 });
+    }).toThrow("Props 'p' of invalid type in component");
  });

  test("can validate an optional props", async () => {
-    class TestWidget extends Component<any, any> {
-      static template = xml`<div>hey</div>`;
+    let TestWidget = class extends Widget {
      static props = { p: { type: String, optional: true } };
    };
-    class Parent extends Component<any, any> {
-      static template = xml`<div><TestWidget p="p"/></div>`;
-      static components = { TestWidget };
-      get p() {
-        return props.p;
-      }
-    };

-    let error;
-    let props;
-    try {
-      props = { p: "key" };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
+    expect(() => {
+      new TestWidget(env, { p: "hey" });
+      new TestWidget(env, {});
+    }).not.toThrow();

-    try {
-      props = {};
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
-
-    try {
-      props = { p: 1 };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeDefined();
-    expect(error.message).toBe(`Props 'p' of invalid type in component 'TestWidget'`);
+    expect(() => {
+      new TestWidget(env, { p: 1 });
+    }).toThrow();
  });

  test("can validate an array with given primitive type", async () => {
-    class TestWidget extends Component<any, any> {
-      static template = xml`<div>hey</div>`;
+    let TestWidget = class extends Widget {
      static props = { p: { type: Array, element: String } };
    };
-    class Parent extends Component<any, any> {
-      static template = xml`<div><TestWidget p="p"/></div>`;
-      static components = { TestWidget };
-      get p() {
-        return props.p;
-      }
-    };

-    let error;
-    let props;
-    try {
-      props = { p: [] };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
+    expect(() => {
+      new TestWidget(env, { p: [] });
+      new TestWidget(env, { p: ["string"] });
+    }).not.toThrow();

-    try {
-      props = { p: ["string"] };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
+    expect(() => {
+      new TestWidget(env, { p: [1] });
+    }).toThrow();

-    try {
-      props = { p: [1] };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeDefined();
-
-    error = undefined;
-    try {
-      props = { p: ["string", 1] };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
+    expect(() => {
+      new TestWidget(env, { p: ["string", 1] });
+    }).toThrow();
  });

  test("can validate an array with multiple sub element types", async () => {
-    class TestWidget extends Component<any, any> {
-      static template = xml`<div>hey</div>`;
+    let TestWidget = class extends Widget {
      static props = { p: { type: Array, element: [String, Boolean] } };
    };
-    class Parent extends Component<any, any> {
-      static template = xml`<div><TestWidget p="p"/></div>`;
-      static components = { TestWidget };
-      get p() {
-        return props.p;
-      }
-    }

-    let error;
-    let props;
-    try {
-      props = { p: [] };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
+    expect(() => {
+      new TestWidget(env, { p: [] });
+      new TestWidget(env, { p: ["string"] });
+      new TestWidget(env, { p: [false, true, "string"] });
+    }).not.toThrow();

-    try {
-      props = { p: ["string"] };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
-
-    try {
-      props = { p: [false, true, "string"] };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
-
-    try {
-      props = { p: [true, 1] };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeDefined();
-    expect(error.message).toBe(`Props 'p' of invalid type in component 'TestWidget'`);
+    expect(() => {
+      new TestWidget(env, { p: [true, 1] });
+    }).toThrow();
  });

  test("can validate an object with simple shape", async () => {
-    class TestWidget extends Component<any, any> {
-      static template = xml`<div>hey</div>`;
+    let TestWidget = class extends Widget {
      static props = {
        p: { type: Object, shape: { id: Number, url: String } }
      };
    };
-    class Parent extends Component<any, any> {
-      static template = xml`<div><TestWidget p="p"/></div>`;
-      static components = { TestWidget };
-      get p() {
-        return props.p;
-      }
-    }

-    let error;
-    let props;
-    try {
-      props = { p: { id: 1, url: "url" } };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
+    expect(() => {
+      new TestWidget(env, { p: { id: 1, url: "url" } });
+      new TestWidget(env, { p: { id: 1, url: "url", extra: true } });
+    }).not.toThrow();

-    try {
-      props = { p: { id: 1, url: "url", extra: true } };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
+    expect(() => {
+      new TestWidget(env, { p: { id: "1", url: "url" } });
+    }).toThrow();

-    try {
-      props = { p: { id: "1", url: "url" } };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeDefined();
-    expect(error.message).toBe(`Props 'p' of invalid type in component 'TestWidget'`);
-
-    error = undefined;
-    try {
-      props = { p: { id: 1 } };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeDefined();
-    expect(error.message).toBe(`Props 'p' of invalid type in component 'TestWidget'`);
+    expect(() => {
+      new TestWidget(env, { p: { id: 1 } });
+    }).toThrow();
  });

  test("can validate recursively complicated prop def", async () => {
-    class TestWidget extends Component<any, any> {
-      static template = xml`<div>hey</div>`;
+    let TestWidget = class extends Widget {
      static props = {
        p: {
          type: Object,
@@ -463,43 +211,15 @@ describe("props validation", () => {
        }
      };
    };
-    class Parent extends Component<any, any> {
-      static template = xml`<div><TestWidget p="p"/></div>`;
-      static components = { TestWidget };
-      get p() {
-        return props.p;
-      }
-    }

-    let error;
-    let props;
-    try {
-      props = { p: { id: 1, url: true } };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
+    expect(() => {
+      new TestWidget(env, { p: { id: 1, url: true } });
+      new TestWidget(env, { p: { id: 1, url: [12] } });
+    }).not.toThrow();

-    try {
-      props = { p: { id: 1, url: [12] } };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeUndefined();
-
-    try {
-      props = { p: { id: 1, url: [12, true] } };
-      const p = new Parent();
-      await p.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeDefined();
-    expect(error.message).toBe(`Props 'p' of invalid type in component 'TestWidget'`);
+    expect(() => {
+      new TestWidget(env, { p: { id: 1, url: [12, true] } });
+    }).toThrow();
  });

  test("props are validated in dev mode (code snapshot)", async () => {
@@ -517,7 +237,7 @@ describe("props validation", () => {
    class App extends Widget {
      static components = { Child };
    }
-    const app = new App();
+    const app = new App(env);
    await app.mount(fixture);
    expect(fixture.innerHTML).toBe("<div><div>1</div></div>");
    // need to make sure there are 2 call to update props. one at component
@@ -590,131 +310,34 @@ describe("props validation", () => {
      QWeb.utils.validateProps(TestWidget, { message: null });
    }).toThrow();
  });
-
-  test("missing required boolean prop causes an error", async () => {
-    class TestWidget extends Widget {
-      static props = ["p"];
-      static template = xml`<span><t t-if="props.p">hey</t></span>`;
-    }
-
-    class App extends Widget {
-      static template = xml`<div><TestWidget/></div>`;
-      static components = { TestWidget };
-    }
-
-    const w = new App(undefined, {});
-    let error;
-    try {
-      await w.mount(fixture);
-    } catch (e) {
-      error = e;
-    }
-    expect(error).toBeDefined();
-    expect(error.message).toBe("Missing props 'p' (component 'TestWidget')");
-  });
-
-  test("props are validated whenever component is updated", async () => {
-    let error;
-    class TestWidget extends Component<any, any> {
-      static props = { p: { type: Number } };
-      static template = xml`<div><t t-esc="props.p"/></div>`;
-
-      async __updateProps() {
-        try {
-          await Component.prototype.__updateProps.apply(this, arguments);
-        } catch (e) {
-          error = e;
-        }
-      }
-    }
-    class Parent extends Component<any, any> {
-      static template = xml`<div><TestWidget p="state.p"/></div>`;
-      static components = { TestWidget };
-      state: any = useState({ p: 1 });
-    }
-
-    const w = new Parent();
-    await w.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><div>1</div></div>");
-
-    w.state.p = undefined;
-    await nextTick();
-    expect(error).toBeDefined();
-    expect(error.message).toBe("Missing props 'p' (component 'TestWidget')");
-  });
-
-  test("default values are applied before validating props at update", async () => {
-    class TestWidget extends Component<any, any> {
-      static props = { p: { type: Number } };
-      static template = xml`<div><t t-esc="props.p"/></div>`;
-      static defaultProps = { p: 4 };
-    }
-    class Parent extends Component<any, any> {
-      static template = xml`<div><TestWidget p="state.p"/></div>`;
-      static components = { TestWidget };
-      state: any = useState({ p: 1 });
-    }
-
-    const w = new Parent();
-    await w.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><div>1</div></div>");
-
-    w.state.p = undefined;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><div>4</div></div>");
-  });
 });

 describe("default props", () => {
  test("can set default values", async () => {
-    class TestWidget extends Component<any, any> {
+    class TestWidget extends Widget {
      static defaultProps = { p: 4 };
-      static template = xml`<div><t t-esc="props.p"/></div>`;
-    }
-    class Parent extends Component<any, any> {
-      static template = xml`<div><TestWidget /></div>`;
-      static components = { TestWidget };
    }

-    const w = new Parent();
-    await w.mount(fixture);
-    expect(fixture.innerHTML).toBe('<div><div>4</div></div>');
+    const w = new TestWidget(env, {});
+    expect(w.props.p).toBe(4);
  });

  test("default values are also set whenever component is updated", async () => {
    class TestWidget extends Widget {
-      static template = xml`<div><t t-esc="props.p"/></div>`;
      static defaultProps = { p: 4 };
    }
-    class Parent extends Widget {
-      static template = xml`<div><TestWidget p="state.p"/></div>`;
-      static components = { TestWidget };
-      state: any = useState({ p: 1 });
-    }
+    env.qweb.addTemplates(`
+        <templates>
+            <div t-name="TestWidget"><t t-esc="props.p"/></div>
+        </templates>`);

-    const w = new Parent();
+    const w = new TestWidget(env, { p: 1 });
    await w.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><div>1</div></div>");
-
-    w.state.p = undefined;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><div>4</div></div>");
-  });
-
-  test("can set default required boolean values", async () => {
-    class TestWidget extends Widget {
-      static props = ["p", "q"];
-      static defaultProps = { p: true, q: false };
-      static template = xml`<span><t t-if="props.p">hey</t><t t-if="!props.q">hey</t></span>`;
-    }
-
-    class App extends Widget {
-      static template = xml`<div><TestWidget/></div>`;
-      static components = { TestWidget };
-    }
-
-    const w = new App(undefined, {});
-    await w.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>heyhey</span></div>");
+    expect(fixture.innerHTML).toMatchSnapshot();
+    const fiber = w.__createFiber(false, undefined, undefined, undefined);
+    await w.__updateProps({}, fiber);
+    await w.render();
+    expect(w.props.p).toBe(4);
+    expect(fixture.innerHTML).toMatchSnapshot();
  });
 });
@@ -1,306 +0,0 @@
-import { makeDeferred, makeTestEnv, makeTestFixture, nextTick } from "./helpers";
-import { Component } from "../src/component/component";
-import { Context, useContext } from "../src/context";
-import { config } from "../src/config";
-import { xml } from "../src/tags";
-import { useState } from "../src/hooks";
-
-//------------------------------------------------------------------------------
-// Setup and helpers
-//------------------------------------------------------------------------------
-
-// We create before each test:
-// - fixture: a div, appended to the DOM, intended to be the target of dom
-//   manipulations.  Note that it is removed after each test.
-// - a test env, necessary to create components, that is set as env
-
-let fixture: HTMLElement;
-
-beforeEach(() => {
-  fixture = makeTestFixture();
-  config.env = makeTestEnv();
-});
-
-afterEach(() => {
-  fixture.remove();
-});
-
-//------------------------------------------------------------------------------
-// Tests
-//------------------------------------------------------------------------------
-
-describe("Context", () => {
-  test("very simple use, with initial value", async () => {
-    const testContext = new Context({ value: 123 });
-
-    class Test extends Component<any, any> {
-      static template = xml`<div><t t-esc="contextObj.value"/></div>`;
-      contextObj = useContext(testContext);
-    }
-    const test = new Test();
-    await test.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div>123</div>");
-  });
-
-  test("useContext hook is reactive, for one component", async () => {
-    const testContext = new Context({ value: 123 });
-
-    class Test extends Component<any, any> {
-      static template = xml`<div><t t-esc="contextObj.value"/></div>`;
-      contextObj = useContext(testContext);
-    }
-    const test = new Test();
-    await test.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div>123</div>");
-    test.contextObj.value = 321;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div>321</div>");
-  });
-
-  test("two components can subscribe to same context", async () => {
-    const testContext = new Context({ value: 123 });
-
-    class Child extends Component<any, any> {
-      static template = xml`<span><t t-esc="contextObj.value"/></span>`;
-      contextObj = useContext(testContext);
-    }
-    class Parent extends Component<any, any> {
-      static template = xml`<div><Child /><Child /></div>`;
-      static components = { Child };
-    }
-    const parent = new Parent();
-    await parent.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>123</span><span>123</span></div>");
-    testContext.state.value = 321;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>321</span><span>321</span></div>");
-  });
-
-  test("two async components are updated in parallel", async () => {
-    const testContext = new Context({ value: 123 });
-    const def = makeDeferred();
-    const steps: string[] = [];
-
-    class Child extends Component<any, any> {
-      static template = xml`<span><t t-esc="contextObj.value"/></span>`;
-      contextObj = useContext(testContext);
-      async render() {
-        steps.push("render");
-        await def;
-        return super.render();
-      }
-    }
-
-    class Parent extends Component<any, any> {
-      static template = xml`<div><Child /><Child /></div>`;
-      static components = { Child };
-    }
-    const parent = new Parent();
-    await parent.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>123</span><span>123</span></div>");
-    testContext.state.value = 321;
-    await nextTick();
-    expect(steps).toEqual(["render", "render"]);
-    expect(fixture.innerHTML).toBe("<div><span>123</span><span>123</span></div>");
-    def.resolve();
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>321</span><span>321</span></div>");
-  });
-
-  test("two async components on two levels are updated in parallel", async () => {
-    const testContext = new Context({ value: 123 });
-    const def = makeDeferred();
-    const steps: string[] = [];
-
-    class SlowComp extends Component<any, any> {
-      static template = xml`<p><t t-esc="props.value"/></p>`;
-      willUpdateProps() {
-        return def;
-      }
-    }
-    class Child extends Component<any, any> {
-      static template = xml`<span><SlowComp value="contextObj.value"/></span>`;
-      static components = { SlowComp };
-      contextObj = useContext(testContext);
-
-      render() {
-        steps.push("render");
-        return super.render();
-      }
-    }
-
-    class Parent extends Component<any, any> {
-      static template = xml`<div><Child /><Child /></div>`;
-      static components = { Child };
-    }
-
-    class App extends Component<any, any> {
-      static template = xml`<div><Child /><Parent /></div>`;
-      static components = { Child, Parent };
-    }
-
-    const app = new App();
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe(
-      "<div><span><p>123</p></span><div><span><p>123</p></span><span><p>123</p></span></div></div>"
-    );
-    testContext.state.value = 321;
-    await nextTick();
-    expect(steps).toEqual(["render"]);
-    expect(fixture.innerHTML).toBe(
-      "<div><span><p>123</p></span><div><span><p>123</p></span><span><p>123</p></span></div></div>"
-    );
-    def.resolve();
-    await nextTick();
-    expect(steps).toEqual(["render", "render", "render"]);
-    expect(fixture.innerHTML).toBe(
-      "<div><span><p>321</p></span><div><span><p>321</p></span><span><p>321</p></span></div></div>"
-    );
-  });
-
-  test("one components can subscribe twice to same context", async () => {
-    const testContext = new Context({ a: 1, b: 2 });
-    const steps: string[] = [];
-
-    class Child extends Component<any, any> {
-      static template = xml`<span><t t-esc="contextObj1.a"/><t t-esc="contextObj2.b"/></span>`;
-      contextObj1 = useContext(testContext);
-      contextObj2 = useContext(testContext);
-      __render(fiber) {
-        steps.push("child");
-        return super.__render(fiber);
-      }
-    }
-    class Parent extends Component<any, any> {
-      static template = xml`<div><Child /></div>`;
-      static components = { Child };
-    }
-    const parent = new Parent();
-    await parent.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>12</span></div>");
-    expect(steps).toEqual(["child"]);
-    testContext.state.a = 3;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>32</span></div>");
-    expect(steps).toEqual(["child", "child"]);
-  });
-
-  test("parent and children subscribed to same context", async () => {
-    const testContext = new Context({ a: 123, b: 321 });
-    const steps: string[] = [];
-
-    class Child extends Component<any, any> {
-      static template = xml`<span><t t-esc="contextObj.a"/></span>`;
-      contextObj = useContext(testContext);
-      __render(fiber) {
-        steps.push("child");
-        return super.__render(fiber);
-      }
-    }
-    class Parent extends Component<any, any> {
-      static template = xml`<div><Child /><t t-esc="contextObj.b"/></div>`;
-      static components = { Child };
-      contextObj = useContext(testContext);
-      __render(fiber) {
-        steps.push("parent");
-        return super.__render(fiber);
-      }
-    }
-    const parent = new Parent();
-    await parent.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>123</span>321</div>");
-    expect(steps).toEqual(["parent", "child"]);
-
-    parent.contextObj.a = 124;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>124</span>321</div>");
-
-    // we only  want one render from the child here, not two
-    expect(steps).toEqual(["parent", "child", "parent", "child"]);
-  });
-
-  test("destroyed component is inactive", async () => {
-    const testContext = new Context({ a: 123 });
-    const steps: string[] = [];
-
-    class Child extends Component<any, any> {
-      static template = xml`<span><t t-esc="contextObj.a"/></span>`;
-      contextObj = useContext(testContext);
-      __render(fiber) {
-        steps.push("child");
-        return super.__render(fiber);
-      }
-    }
-    class Parent extends Component<any, any> {
-      static template = xml`<div><Child t-if="state.flag"/></div>`;
-      static components = { Child };
-      state = useState({ flag: true });
-      __render(fiber) {
-        steps.push("parent");
-        return super.__render(fiber);
-      }
-    }
-    const parent = new Parent();
-    await parent.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>123</span></div>");
-    expect(steps).toEqual(["parent", "child"]);
-    expect(testContext.subscriptions.update.length).toBe(1);
-
-    parent.state.flag = false;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div></div>");
-    expect(steps).toEqual(["parent", "child", "parent"]);
-    // kind of whitebox...
-    // we make sure we do not have any pending subscriptions to the 'update'
-    // event
-    expect(testContext.subscriptions.update.length).toBe(0);
-  });
-
-  test("concurrent renderings", async () => {
-    const testContext = new Context({ x: { n: 1 }, key: "x" });
-    const def = makeDeferred();
-    let stateC;
-    class ComponentC extends Component<any, any> {
-      static template = xml`<span><t t-esc="context[props.key].n"/><t t-esc="state.x"/></span>`;
-      context = useContext(testContext);
-      state = useState({ x: "a" });
-
-      constructor(parent, props) {
-        super(parent, props);
-        stateC = this.state;
-      }
-    }
-    class ComponentB extends Component<any, any> {
-      static components = { ComponentC };
-      static template = xml`<p><ComponentC key="props.key"/></p>`;
-
-      willUpdateProps() {
-        return def;
-      }
-    }
-    class ComponentA extends Component<any, any> {
-      static components = { ComponentB };
-      static template = xml`<div><ComponentB key="context.key"/></div>`;
-      context = useContext(testContext);
-    }
-
-    const component = new ComponentA();
-    await component.mount(fixture);
-
-    expect(fixture.innerHTML).toBe("<div><p><span>1a</span></p></div>");
-    testContext.state.key = "y";
-    testContext.state.y = { n: 2 };
-    delete testContext.state.x;
-    await nextTick();
-
-    expect(fixture.innerHTML).toBe("<div><p><span>1a</span></p></div>");
-    stateC.x = "b";
-    await nextTick();
-
-    expect(fixture.innerHTML).toBe("<div><p><span>1a</span></p></div>");
-    def.resolve();
-    await nextTick();
-
-    expect(fixture.innerHTML).toBe("<div><p><span>2b</span></p></div>");
-  });
-});
@@ -8,11 +8,13 @@ describe("observer", () => {

    expect(typeof obj).toBe("object");
    expect(observer.revNumber(obj)).toBe(1);
+    expect(observer.deepRevNumber(obj)).toBe(1);
    expect(observer.rev).toBe(1);

    const obj2: any = observer.observe({ a: 1 });
    expect(observer.revNumber(obj2)).toBe(1);
    expect(observer.revNumber(obj)).toBe(1);
+    expect(observer.deepRevNumber(obj)).toBe(1);
    expect(observer.rev).toBe(1);

    obj2.a = 2;
@@ -31,19 +33,23 @@ describe("observer", () => {
    const obj: any = observer.observe({ a: null, b: undefined });

    expect(observer.revNumber(obj)).toBe(1);
+    expect(observer.deepRevNumber(obj)).toBe(1);
    expect(observer.rev).toBe(1);

    obj.a = 3;
    expect(observer.revNumber(obj)).toBe(2);
+    expect(observer.deepRevNumber(obj)).toBe(2);
    expect(observer.rev).toBe(2);

    obj.b = 5;
    expect(observer.revNumber(obj)).toBe(3);
+    expect(observer.deepRevNumber(obj)).toBe(3);
    expect(observer.rev).toBe(3);

    obj.a = null;
    obj.b = undefined;
    expect(observer.revNumber(obj)).toBe(5);
+    expect(observer.deepRevNumber(obj)).toBe(5);
    expect(observer.rev).toBe(5);
    expect(obj).toEqual({
      a: null,
@@ -57,6 +63,7 @@ describe("observer", () => {
    const obj: any = observer.observe({ date });

    expect(observer.revNumber(obj)).toBe(1);
+    expect(observer.deepRevNumber(obj)).toBe(1);
    expect(observer.rev).toBe(1);
    expect(typeof obj.date.getFullYear()).toBe("number");
    expect(obj.date).toBe(date);
@@ -64,6 +71,7 @@ describe("observer", () => {
    obj.date = new Date();

    expect(observer.revNumber(obj)).toBe(2);
+    expect(observer.deepRevNumber(obj)).toBe(2);
    expect(observer.rev).toBe(2);
    expect(obj.date).not.toBe(date);
  });
@@ -74,11 +82,14 @@ describe("observer", () => {

    expect(Array.isArray(obj.arr)).toBe(true);
    expect(observer.revNumber(obj.arr)).toBe(1);
+    expect(observer.deepRevNumber(obj.arr)).toBe(1);
    expect(observer.rev).toBe(1);

    obj.arr[0] = "nope";
    expect(observer.revNumber(obj.arr)).toBe(2);
-    expect(observer.revNumber(obj)).toBe(2);
+    expect(observer.deepRevNumber(obj.arr)).toBe(2);
+    expect(observer.revNumber(obj)).toBe(1);
+    expect(observer.deepRevNumber(obj)).toBe(2);
    expect(observer.rev).toBe(2);
  });

@@ -87,20 +98,24 @@ describe("observer", () => {
    const obj: any = observer.observe({ a: 1 });

    expect(observer.revNumber(obj)).toBe(1);
+    expect(observer.deepRevNumber(obj)).toBe(1);
    expect(observer.rev).toBe(1);

    obj.a = 2;

    expect(observer.revNumber(obj)).toBe(2);
+    expect(observer.deepRevNumber(obj)).toBe(2);
    expect(observer.rev).toBe(2);

    // same value again
    obj.a = 2;
    expect(observer.revNumber(obj)).toBe(2);
+    expect(observer.deepRevNumber(obj)).toBe(2);
    expect(observer.rev).toBe(2);

    obj.a = 3;
    expect(observer.revNumber(obj)).toBe(3);
+    expect(observer.deepRevNumber(obj)).toBe(3);
    expect(observer.rev).toBe(3);
  });

@@ -111,16 +126,19 @@ describe("observer", () => {
    expect(Array.isArray(arr)).toBe(true);
    expect(arr.length).toBe(0);
    expect(observer.revNumber(arr)).toBe(1);
+    expect(observer.deepRevNumber(arr)).toBe(1);
    expect(observer.rev).toBe(1);

    arr.push(1);
    expect(observer.revNumber(arr)).toBe(2);
+    expect(observer.deepRevNumber(arr)).toBe(2);
    expect(observer.rev).toBe(2);
    expect(arr.length).toBe(1);
    expect(arr).toEqual([1]);

    arr.splice(1, 0, "hey");
    expect(observer.revNumber(arr)).toBe(3);
+    expect(observer.deepRevNumber(arr)).toBe(3);
    expect(observer.rev).toBe(3);
    expect(arr).toEqual([1, "hey"]);
    expect(arr.length).toBe(2);
@@ -128,6 +146,7 @@ describe("observer", () => {
    arr.unshift("lindemans");
    //it generates 3 primitive operations
    expect(observer.revNumber(arr)).toBe(6);
+    expect(observer.deepRevNumber(arr)).toBe(6);
    expect(observer.rev).toBe(6);
    expect(arr).toEqual(["lindemans", 1, "hey"]);
    expect(arr.length).toBe(3);
@@ -135,18 +154,21 @@ describe("observer", () => {
    arr.reverse();
    //it generates 2 primitive operations
    expect(observer.revNumber(arr)).toBe(8);
+    expect(observer.deepRevNumber(arr)).toBe(8);
    expect(observer.rev).toBe(8);
    expect(arr).toEqual(["hey", 1, "lindemans"]);
    expect(arr.length).toBe(3);

    arr.pop(); // one set, one delete
    expect(observer.revNumber(arr)).toBe(10);
+    expect(observer.deepRevNumber(arr)).toBe(10);
    expect(observer.rev).toBe(10);
    expect(arr).toEqual(["hey", 1]);
    expect(arr.length).toBe(2);

    arr.shift(); // 2 sets, 1 delete
    expect(observer.revNumber(arr)).toBe(13);
+    expect(observer.deepRevNumber(arr)).toBe(13);
    expect(observer.rev).toBe(13);
    expect(arr).toEqual([1]);
    expect(arr.length).toBe(1);
@@ -165,7 +187,8 @@ describe("observer", () => {
    arr[0].kriek = 6;

    expect(observer.rev).toBe(3);
-    expect(observer.revNumber(arr)).toBe(3);
+    expect(observer.revNumber(arr)).toBe(2);
+    expect(observer.deepRevNumber(arr)).toBe(3);
    expect(observer.revNumber(arr[0])).toBe(3);
  });

@@ -215,6 +238,7 @@ describe("observer", () => {

    expect(observer.rev).toBe(1);
    expect(observer.revNumber(state)).toBe(1);
+    expect(observer.deepRevNumber(state)).toBe(1);
    expect(observer.notifyCB).toBeCalledTimes(0);

    state[1] = "b";
@@ -223,6 +247,7 @@ describe("observer", () => {

    expect(observer.rev).toBe(2);
    expect(observer.revNumber(state)).toBe(2);
+    expect(observer.deepRevNumber(state)).toBe(2);
    expect(observer.notifyCB).toBeCalledTimes(1);

    expect(state).toEqual(["a", "b"]);
@@ -234,11 +259,13 @@ describe("observer", () => {

    expect(observer.rev).toBe(1);
    expect(observer.revNumber(state.arr)).toBe(1);
+    expect(observer.deepRevNumber(state.arr)).toBe(1);
    expect(state.arr.length).toBe(0);

    state.arr.push(1);
    expect(observer.rev).toBe(2);
    expect(observer.revNumber(state.arr)).toBe(2);
+    expect(observer.deepRevNumber(state.arr)).toBe(2);
    expect(state.arr.length).toBe(1);
  });

@@ -253,7 +280,7 @@ describe("observer", () => {

    state.arr[0].something = 2;
    expect(observer.rev).toBe(2);
-    expect(observer.revNumber(state.arr)).toBe(2);
+    expect(observer.revNumber(state.arr)).toBe(1);
    expect(observer.revNumber(state.arr[0])).toBe(2);
  });

@@ -267,7 +294,7 @@ describe("observer", () => {

    state.a.b = 2;
    expect(observer.rev).toBe(2);
-    expect(observer.revNumber(state)).toBe(2);
+    expect(observer.revNumber(state)).toBe(1);
    expect(observer.revNumber(state.a)).toBe(2);
  });

@@ -285,7 +312,7 @@ describe("observer", () => {
    expect(observer.revNumber(obj.a)).toBe(2);
    obj.a.b = 3;
    expect(observer.rev).toBe(3);
-    expect(observer.revNumber(obj)).toBe(3);
+    expect(observer.revNumber(obj)).toBe(2);
    expect(observer.revNumber(obj.a)).toBe(3);
  });

@@ -293,18 +320,22 @@ describe("observer", () => {
    const observer = new Observer();
    const state: any = observer.observe({ o: { a: 1 }, arr: [1], n: 13 });
    expect(observer.revNumber(state)).toBe(1);
+    expect(observer.deepRevNumber(state)).toBe(1);

    state.o.a = 2;
    expect(observer.rev).toBe(2);
-    expect(observer.revNumber(state)).toBe(2);
+    expect(observer.revNumber(state)).toBe(1);
+    expect(observer.deepRevNumber(state)).toBe(2);

    state.arr.push(2);
    expect(observer.rev).toBe(3);
-    expect(observer.revNumber(state)).toBe(3);
+    expect(observer.revNumber(state)).toBe(1);
+    expect(observer.deepRevNumber(state)).toBe(3);

    state.n = 155;
    expect(observer.rev).toBe(4);
-    expect(observer.revNumber(state)).toBe(4);
+    expect(observer.revNumber(state)).toBe(2);
+    expect(observer.deepRevNumber(state)).toBe(4);
  });

  test("properly handle already observed state", () => {
@@ -330,15 +361,18 @@ describe("observer", () => {
    const obj: any = observer.observe({});

    expect(observer.revNumber(obj)).toBe(1);
+    expect(observer.deepRevNumber(obj)).toBe(1);
    expect(observer.rev).toBe(1);

    obj.aku = "always finds annoying problems";
    expect(observer.revNumber(obj)).toBe(2);
+    expect(observer.deepRevNumber(obj)).toBe(2);
    expect(observer.rev).toBe(2);

    obj.aku = "always finds good problems";

    expect(observer.revNumber(obj)).toBe(3);
+    expect(observer.deepRevNumber(obj)).toBe(3);
    expect(observer.rev).toBe(3);
  });

@@ -382,7 +416,7 @@ describe("observer", () => {
    expect(observer.revNumber(obj2)).toBe(1);

    obj2.key = 3;
-    expect(observer.revNumber(obj1)).toBe(2);
+    expect(observer.revNumber(obj1)).toBe(1);
    expect(observer.revNumber(obj2)).toBe(2);
  });

@@ -6,9 +6,35 @@
 */
 import * as fs from "fs";

-//--------------------------------------------------------------------------
-// Helpers
-//--------------------------------------------------------------------------
+const LINK_REGEXP = /\[([^\[]+)\]\(([^\)]+)\)/g;
+const HEADING_REGEXP = /\n(#+\s*)(.*)/g;
+
+// files to be checked
+function getFiles(): string[] {
+  const DOCFILES = fs.readdirSync("doc").map(f => `doc/${f}`);
+  const MAINREADME = "README.md";
+  return DOCFILES.concat(MAINREADME);
+}
+
+test("All markdown links work", () => {
+  let linkNumber = 0;
+  let invalidLinkNumber = 0;
+  const files = getFiles();
+  const data = readDocData(files);
+  for (let file of data) {
+    for (let link of file.links) {
+      // DEBUG: uncomment next line
+      // console.warn(`Checking "${link.name}" in "${file.name}"`);
+      linkNumber++;
+      if (!isLinkValid(link, file, data)) {
+        console.warn(`Invalid Link: "${link.name}" in "${file.name}"`);
+        invalidLinkNumber++;
+      }
+    }
+  }
+  expect(invalidLinkNumber).toBe(0);
+  expect(linkNumber).toBeGreaterThan(10);
+});

 interface MarkDownLink {
  name: string;
@@ -22,127 +48,34 @@ interface MarkDownSection {

 interface FileData {
  name: string;
-  path: string[];
-  fullName: string;
  links: MarkDownLink[];
  sections: MarkDownSection[];
 }

-const LINK_REGEXP = /\[([^\[]+)\]\(([^\)]+)\)/g;
-const HEADING_REGEXP = /\n(#+\s*)(.*)/g;
-
-export function addMardownData(fileData): void {
-  const sep = fileData.path.length > 0 ? "/" : "";
-  const fullName = fileData.path.join("/") + sep + fileData.name;
-  const content = fs.readFileSync(fullName, { encoding: "utf8" });
-  let m;
-  // get links info
-  do {
-    m = LINK_REGEXP.exec(content);
-    if (m) {
-      fileData.links.push({ name: m[0], link: m[2] });
-    }
-  } while (m);
-  // get sections info
-  do {
-    m = HEADING_REGEXP.exec(content);
-    if (m) {
-      fileData.sections.push({ name: m[0], slug: slugify(m[2]) });
-    }
-  } while (m);
-}
-
-/**
- * Returns a list of FileData corresponding to all files that need to be
- * validated.
- */
-function getFiles(path: string[] = []): FileData[] {
-  if (path.length === 0) {
-    const baseFiles: FileData[] = [
-      { name: "README.md", path: [], links: [], sections: [], fullName: "README.md" },
-      { name: "roadmap.md", path: [], links: [], sections: [], fullName: "roadmap.md" }
-    ];
-    const rest = getFiles(["doc"]);
-    const result = baseFiles.concat(rest);
-    result.forEach(addMardownData);
-    return result;
-  }
-  const files = fs.readdirSync(path.join("/"), { withFileTypes: true }).map(f => {
-    if (f.isDirectory()) {
-      return getFiles(path.concat(f.name));
-    }
-    const fullName = path.join("/") + (path.length > 0 ? "/" : "") + f.name;
-    return [
-      {
-        name: f.name,
-        path,
-        links: [],
-        sections: [],
-        fullName
-      }
-    ];
-  });
-  return Array.prototype.concat(...files);
-}
-
-const LOCAL_FILES = ["LICENSE"];
-export function isLinkValid(link: MarkDownLink, current: FileData, files: FileData[]): boolean {
-  if (link.link.startsWith("http")) {
-    // no check on external links
-    return true;
-  }
-  // Step 1: extract path, name, hash
-  //      path = ['doc', 'architecture]
-  //      name = 'rendering.md'
-  //      hash = 'blabla' (or '' if no hash)
-
+function isLinkValid(link: MarkDownLink, current: FileData, files: FileData[]): boolean {
  const parts = link.link.split("#");
-  const hash = parts[1] || "";
-  let name;
-  let path;
-  if (parts[0]) {
-    let temp = parts[0].split("/");
-    name = temp[temp.length - 1];
-    temp.splice(-1);
-    path = current.path.slice();
-    for (let elem of temp) {
-      if (elem === "..") {
-        path.splice(-1);
-      } else if (elem !== ".") {
-        path.push(elem);
+  const currentParts = current.name.split("/");
+  const path = currentParts.length > 1 ? currentParts[0] + "/" : "";
+  const fullName = path + parts[0];
+  if (parts.length === 1) {
+    // no # in url
+    if (parts[0].endsWith(".md")) {
+      // it is a local md file
+      if (!files.find(f => f.name === fullName)) {
+        return false;
      }
    }
  } else {
-    // there are no file name, so this is a relative link to the current file
-    name = current.name;
-    path = current.path;
-  }
-
-  // Step 2: build normalized link file name
-  const linkFullName = path.join("/") + (path.length > 0 ? "/" : "") + name;
-
-  // Step 3: check link name against white list of local files
-  if (LOCAL_FILES.includes(linkFullName)) {
-    return true;
-  }
-
-  // Step 4: check if there is a matching file
-  let target: FileData | undefined = files.find(f => f.fullName === linkFullName);
-  if (!target) {
-    return false;
-  }
-
-  // Step 5: if necessary, check if there is a corresponding link inside the target
-  // link name
-  if (hash) {
-    if (!target.sections.find(s => s.slug === hash)) {
+    const file = parts[0] === "" ? current : files.find(f => f.name === fullName);
+    if (!file) {
+      return false;
+    }
+    if (!file.sections.find(s => s.slug === parts[1])) {
      return false;
    }
  }
-
  return true;
 }
-
 // adapted from https://medium.com/@mhagemann/the-ultimate-way-to-slugify-a-url-string-in-javascript-b8e4a0d849e1
 function slugify(str) {
  const a = "àáäâãåăæçèéëêǵḧìíïîḿńǹñòóöôœøṕŕßśșțùúüûǘẃẍÿź·_,:;";
@@ -161,23 +94,33 @@ function slugify(str) {
    .replace(/-+$/, ""); // Trim - from end of text
 }

-//--------------------------------------------------------------------------
-// Test
-//--------------------------------------------------------------------------
+function readDocData(files: string[]): FileData[] {
+  const result: FileData[] = [];

-test("All markdown links work", () => {
-  let linkNumber = 0;
-  let invalidLinkNumber = 0;
-  const data = getFiles();
-  for (let file of data) {
-    for (let link of file.links) {
-      linkNumber++;
-      if (!isLinkValid(link, file, data)) {
-        console.warn(`Invalid Link: "${link.name}" in "${file.name}"`);
-        invalidLinkNumber++;
+  for (let file of files) {
+    const fileData: FileData = {
+      name: file,
+      links: [],
+      sections: []
+    };
+    const content = fs.readFileSync(file, { encoding: "utf8" });
+    let m;
+    // get links info
+    do {
+      m = LINK_REGEXP.exec(content);
+      if (m) {
+        fileData.links.push({ name: m[0], link: m[2] });
      }
-    }
+    } while (m);
+    // get sections info
+    do {
+      m = HEADING_REGEXP.exec(content);
+      if (m) {
+        fileData.sections.push({ name: m[0], slug: slugify(m[2]) });
+      }
+    } while (m);
+
+    result.push(fileData);
  }
-  expect(invalidLinkNumber).toBe(0);
-  expect(linkNumber).toBeGreaterThan(10);
-});
+  return result;
+}
@@ -1,17 +1,10 @@
 import { Env } from "../src/component/component";
-import { scheduler } from "../src/component/scheduler";
 import { EvalContext, QWeb } from "../src/qweb/qweb";
 import { patch } from "../src/vdom";
 import "../src/qweb/base_directives";
 import "../src/qweb/extensions";
 import "../src/component/directive";

-// modifies scheduler to make it faster to test components
-scheduler.requestAnimationFrame = function(callback: FrameRequestCallback) {
-  setTimeout(callback, 1);
-  return 1;
-};
-
 // Some static cleanup
 let nextSlotId;
 let slots;
@@ -37,10 +30,8 @@ export function nextMicroTick(): Promise<void> {
  return Promise.resolve();
 }

-export async function nextTick(): Promise<void> {
-  return new Promise(function(resolve) {
-    setTimeout(() => scheduler.requestAnimationFrame(() => resolve()));
-  });
+export function nextTick(): Promise<void> {
+  return new Promise(resolve => setTimeout(resolve));
 }

 export function makeTestFixture() {
@@ -1,6 +1,5 @@
 import { makeTestEnv, makeTestFixture, nextTick } from "./helpers";
 import { Component, Env } from "../src/component/component";
-import { config } from "../src/config";
 import {
  useState,
  onMounted,
@@ -8,8 +7,6 @@ import {
  useRef,
  onPatched,
  onWillPatch,
-  onWillStart,
-  onWillUpdateProps,
  useSubEnv
 } from "../src/hooks";
 import { xml } from "../src/tags";
@@ -29,7 +26,6 @@ let env: Env;
 beforeEach(() => {
  fixture = makeTestFixture();
  env = makeTestEnv();
-  config.env = env;
 });

 afterEach(() => {
@@ -46,7 +42,7 @@ describe("hooks", () => {
      static template = xml`<div><t t-esc="counter.value"/></div>`;
      counter = useState({ value: 42 });
    }
-    const counter = new Counter();
+    const counter = new Counter(env);
    await counter.mount(fixture);
    expect(fixture.innerHTML).toBe("<div>42</div>");
    counter.counter.value = 3;
@@ -66,12 +62,12 @@ describe("hooks", () => {
    }
    class MyComponent extends Component<any, any> {
      static template = xml`<div>hey</div>`;
-      constructor() {
-        super();
+      constructor(env) {
+        super(env);
        useMyHook();
      }
    }
-    const component = new MyComponent();
+    const component = new MyComponent(env);
    await component.mount(fixture);
    expect(component).not.toHaveProperty("mounted");
    expect(component).not.toHaveProperty("willUnmount");
@@ -82,40 +78,6 @@ describe("hooks", () => {
    expect(steps).toEqual(["mounted", "willunmount"]);
  });

-  test("can use onMounted, onWillUnmount, part 2", async () => {
-    const steps: string[] = [];
-    function useMyHook() {
-      onMounted(() => {
-        steps.push("mounted");
-      });
-      onWillUnmount(() => {
-        steps.push("willunmount");
-      });
-    }
-    class MyComponent extends Component<any, any> {
-      static template = xml`<div>hey</div>`;
-      constructor(parent, props) {
-        super(parent, props);
-        useMyHook();
-      }
-    }
-
-    class Parent extends Component<any, any> {
-      static template = xml`<div><MyComponent t-if="state.flag"/></div>`;
-      static components = { MyComponent };
-      state = useState({ flag: true });
-    }
-    const parent = new Parent();
-    await parent.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><div>hey</div></div>");
-    expect(steps).toEqual(["mounted"]);
-
-    parent.state.flag = false;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div></div>");
-    expect(steps).toEqual(["mounted", "willunmount"]);
-  });
-
  test("mounted, willUnmount, onMounted, onWillUnmount order", async () => {
    const steps: string[] = [];
    function useMyHook() {
@@ -128,8 +90,8 @@ describe("hooks", () => {
    }
    class MyComponent extends Component<any, any> {
      static template = xml`<div>hey</div>`;
-      constructor() {
-        super();
+      constructor(env) {
+        super(env);
        useMyHook();
      }
      mounted() {
@@ -139,7 +101,7 @@ describe("hooks", () => {
        steps.push("comp:willunmount");
      }
    }
-    const component = new MyComponent();
+    const component = new MyComponent(env);
    await component.mount(fixture);
    expect(fixture.innerHTML).toBe("<div>hey</div>");
    component.unmount();
@@ -147,46 +109,6 @@ describe("hooks", () => {
    expect(steps).toEqual(["comp:mounted", "hook:mounted", "hook:willunmount", "comp:willunmount"]);
  });

-  test("mounted, willUnmount, onMounted, onWillUnmount order, part 2", async () => {
-    const steps: string[] = [];
-    function useMyHook() {
-      onMounted(() => {
-        steps.push("hook:mounted");
-      });
-      onWillUnmount(() => {
-        steps.push("hook:willunmount");
-      });
-    }
-    class MyComponent extends Component<any, any> {
-      static template = xml`<div>hey</div>`;
-      constructor(parent, props) {
-        super(parent, props);
-        useMyHook();
-      }
-      mounted() {
-        steps.push("comp:mounted");
-      }
-      willUnmount() {
-        steps.push("comp:willunmount");
-      }
-    }
-
-    class Parent extends Component<any, any> {
-      static template = xml`<div><MyComponent t-if="state.flag"/></div>`;
-      static components = { MyComponent };
-      state = useState({ flag: true });
-    }
-
-    const parent = new Parent();
-    await parent.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><div>hey</div></div>");
-    parent.state.flag = false;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div></div>");
-
-    expect(steps).toEqual(["comp:mounted", "hook:mounted", "hook:willunmount", "comp:willunmount"]);
-  });
-
  test("two different call to mounted/willunmount should work", async () => {
    const steps: string[] = [];
    function useMyHook(i) {
@@ -199,13 +121,13 @@ describe("hooks", () => {
    }
    class MyComponent extends Component<any, any> {
      static template = xml`<div>hey</div>`;
-      constructor() {
-        super();
+      constructor(env) {
+        super(env);
        useMyHook(1);
        useMyHook(2);
      }
    }
-    const component = new MyComponent();
+    const component = new MyComponent(env);
    await component.mount(fixture);
    expect(fixture.innerHTML).toBe("<div>hey</div>");
    component.unmount();
@@ -228,7 +150,7 @@ describe("hooks", () => {
        (this.button.el as HTMLButtonElement).innerHTML = String(this.value);
      }
    }
-    const counter = new Counter();
+    const counter = new Counter(env);
    await counter.mount(fixture);
    expect(fixture.innerHTML).toBe("<div><button>0</button></div>");
    counter.increment();
@@ -236,27 +158,6 @@ describe("hooks", () => {
    expect(fixture.innerHTML).toBe("<div><button>1</button></div>");
  });

-  test("useRef hook is null if ref is removed ", async () => {
-    expect.assertions(4);
-    class TestRef extends Component<any, any> {
-      static template = xml`<div><span t-if="state.flag" t-ref="span">owl</span></div>`;
-      spanRef = useRef("span");
-      state = useState({ flag: true });
-      willPatch() {
-        expect(this.spanRef.el).not.toBeNull();
-      }
-      patched() {
-        expect(this.spanRef.el).toBeNull();
-      }
-    }
-    const component = new TestRef();
-    await component.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>owl</span></div>");
-    component.state.flag = false;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div></div>");
-  });
-
  test("can use onPatched, onWillPatch", async () => {
    const steps: string[] = [];
    function useMyHook() {
@@ -272,13 +173,13 @@ describe("hooks", () => {
      static template = xml`<div><t t-if="state.flag">hey</t></div>`;
      state = useState({ flag: true });

-      constructor() {
-        super();
+      constructor(env) {
+        super(env);
        useMyHook();
      }
    }

-    const component = new MyComponent();
+    const component = new MyComponent(env);
    await component.mount(fixture);
    expect(component).not.toHaveProperty("patched");
    expect(component).not.toHaveProperty("willPatch");
@@ -306,8 +207,8 @@ describe("hooks", () => {
      static template = xml`<div><t t-if="state.flag">hey</t></div>`;
      state = useState({ flag: true });

-      constructor() {
-        super();
+      constructor(env) {
+        super(env);
        useMyHook();
      }
      willPatch() {
@@ -317,7 +218,7 @@ describe("hooks", () => {
        steps.push("comp:patched");
      }
    }
-    const component = new MyComponent();
+    const component = new MyComponent(env);
    await component.mount(fixture);
    expect(fixture.innerHTML).toBe("<div>hey</div>");
    component.state.flag = false;
@@ -339,13 +240,13 @@ describe("hooks", () => {
    class MyComponent extends Component<any, any> {
      static template = xml`<div>hey<t t-esc="state.value"/></div>`;
      state = useState({ value: 1 });
-      constructor() {
-        super();
+      constructor(env) {
+        super(env);
        useMyHook(1);
        useMyHook(2);
      }
    }
-    const component = new MyComponent();
+    const component = new MyComponent(env);
    await component.mount(fixture);
    expect(fixture.innerHTML).toBe("<div>hey1</div>");
    component.state.value++;
@@ -379,13 +280,13 @@ describe("hooks", () => {
                <input t-ref="input2"/>
            </div>`;

-        constructor() {
-          super();
+        constructor(env) {
+          super(env);
          useAutofocus("input2");
        }
      }

-      const component = new SomeComponent();
+      const component = new SomeComponent(env);
      await component.mount(fixture);
      expect(fixture.innerHTML).toBe("<div><input><input></div>");
      const input2 = fixture.querySelectorAll("input")[1];
@@ -401,13 +302,13 @@ describe("hooks", () => {
            </div>`;

        state = useState({ flag: false });
-        constructor() {
-          super();
+        constructor(env) {
+          super(env);
          useAutofocus("input2");
        }
      }

-      const component = new SomeComponent();
+      const component = new SomeComponent(env);
      await component.mount(fixture);
      expect(fixture.innerHTML).toBe("<div><input></div>");
      expect(document.activeElement).toBe(document.body);
@@ -422,12 +323,12 @@ describe("hooks", () => {
  test("can use sub env", async () => {
    class TestComponent extends Component<any, any> {
      static template = xml`<div><t t-esc="env.val"/></div>`;
-      constructor() {
-        super();
+      constructor(env) {
+        super(env);
        useSubEnv({ val: 3 });
      }
    }
-    const component = new TestComponent();
+    const component = new TestComponent(env);
    await component.mount(fixture);
    expect(fixture.innerHTML).toBe("<div>3</div>");
    expect(env).not.toHaveProperty("val");
@@ -437,59 +338,22 @@ describe("hooks", () => {
  test("parent and child env", async () => {
    class Child extends Component<any, any> {
      static template = xml`<div><t t-esc="env.val"/></div>`;
-      constructor(parent, props) {
-        super(parent, props);
+      constructor(env) {
+        super(env);
        useSubEnv({ val: 5 });
      }
    }

    class Parent extends Component<any, any> {
      static template = xml`<div><t t-esc="env.val"/><Child/></div>`;
-      static components = { Child };
-      constructor() {
-        super();
+      static components = { Child}
+      constructor(env) {
+        super(env);
        useSubEnv({ val: 3 });
      }
    }
-    const component = new Parent();
+    const component = new Parent(env);
    await component.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div>3<div>5</div></div>");
-  });
-
-  test("can use onWillStart, onWillUpdateProps", async () => {
-    const steps: string[] = [];
-    function useMyHook() {
-      onWillStart(() => {
-        steps.push("onWillStart");
-      });
-      onWillUpdateProps(nextProps => {
-        expect(nextProps).toEqual({ value: 2 });
-        steps.push("onWillUpdateProps");
-      });
-    }
-    class MyComponent extends Component<any, any> {
-      static template = xml`<span><t t-esc="props.value"/></span>`;
-      constructor(parent, props) {
-        super(parent, props);
-        useMyHook();
-      }
-    }
-    class App extends Component<any, any> {
-      static template = xml`<div><MyComponent value="state.value"/></div>`;
-      static components = { MyComponent };
-      state = useState({ value: 1 });
-    }
-
-    const app = new App();
-    await app.mount(fixture);
-    expect(app).not.toHaveProperty("willStart");
-    expect(app).not.toHaveProperty("willUpdateProps");
-    expect(fixture.innerHTML).toBe("<div><span>1</span></div>");
-    expect(steps).toEqual(["onWillStart"]);
-
-    app.state.value = 2;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>2</span></div>");
-    expect(steps).toEqual(["onWillStart", "onWillUpdateProps"]);
+    expect(fixture.innerHTML).toBe( "<div>3<div>5</div></div>");
  });
 });
@@ -1,189 +0,0 @@
-import { AsyncRoot } from "../../src/misc/async_root";
-import { config } from "../../src/config";
-import { useState } from "../../src/hooks";
-import { xml } from "../../src/tags";
-import { makeDeferred, makeTestFixture, makeTestEnv, nextTick } from "../helpers";
-import { Component } from "../../src/component/component";
-
-//------------------------------------------------------------------------------
-// Setup and helpers
-//------------------------------------------------------------------------------
-
-// We create before each test:
-// - fixture: a div, appended to the DOM, intended to be the target of dom
-//   manipulations.  Note that it is removed after each test.
-// - a test env, necessary to create components, that is set as env
-
-let fixture: HTMLElement;
-
-beforeEach(() => {
-  fixture = makeTestFixture();
-  config.env = makeTestEnv();
-});
-
-afterEach(() => {
-  fixture.remove();
-});
-
-describe("Asyncroot", () => {
-  test("delayed component with AsyncRoot component", async () => {
-    let def;
-    class Child extends Component<any, any> {
-      static template = xml`<span><t t-esc="props.val"/></span>`;
-    }
-    class AsyncChild extends Child {
-      willUpdateProps() {
-        return def;
-      }
-    }
-    class Parent extends Component<any, any> {
-      static template = xml`
-          <div>
-            <button t-on-click="updateApp">Update App State</button>
-            <div class="children">
-              <Child val="state.val"/>
-              <AsyncRoot>
-                  <AsyncChild val="state.val"/>
-              </AsyncRoot>
-            </div>
-          </div>`;
-      static components = { Child, AsyncChild, AsyncRoot };
-      state = useState({ val: 0 });
-
-      updateApp() {
-        this.state.val++;
-      }
-    }
-
-    const parent = new Parent();
-    await parent.mount(fixture);
-
-    expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>0</span><span>0</span>");
-
-    // click on button to increment Parent counter
-    def = makeDeferred();
-    fixture.querySelector("button")!.click();
-    await nextTick();
-
-    expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>1</span><span>0</span>");
-
-    def.resolve();
-    await nextTick();
-
-    expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>1</span><span>1</span>");
-  });
-
-  test("fast component with AsyncRoot", async () => {
-    let def;
-    class Child extends Component<any, any> {
-      static template = xml`<span><t t-esc="props.val"/></span>`;
-    }
-    class AsyncChild extends Child {
-      willUpdateProps() {
-        return def;
-      }
-    }
-
-    class Parent extends Component<any, any> {
-      static template = xml`
-          <div>
-            <button t-on-click="updateApp">Update App State</button>
-            <div class="children">
-              <AsyncRoot>
-                <Child val="state.val"/>
-              </AsyncRoot>
-              <AsyncChild val="state.val"/>
-            </div>
-          </div>`;
-      static components = { Child, AsyncChild, AsyncRoot };
-      state = useState({ val: 0 });
-
-      updateApp() {
-        this.state.val++;
-      }
-    }
-
-    const parent = new Parent();
-    await parent.mount(fixture);
-
-    expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>0</span><span>0</span>");
-
-    // click on button to increment Parent counter
-    def = makeDeferred();
-    fixture.querySelector("button")!.click();
-    await nextTick();
-
-    expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>1</span><span>0</span>");
-
-    def.resolve();
-    await nextTick();
-
-    expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>1</span><span>1</span>");
-  });
-
-  test("asyncroot component: mixed re-renderings", async () => {
-    let def;
-    class Child extends Component<any, any> {
-      static template = xml`
-        <span t-on-click="increment">
-          <t t-esc="state.val"/>/<t t-esc="props.val"/>
-        </span>`;
-      state = useState({ val: 0 });
-
-      increment() {
-        this.state.val++;
-      }
-    }
-    class AsyncChild extends Child {
-      willUpdateProps() {
-        return def;
-      }
-    }
-    class Parent extends Component<any, any> {
-      static template = xml`
-        <div>
-          <button t-on-click="updateApp">Update App State</button>
-          <div class="children">
-            <Child val="state.val"/>
-            <AsyncRoot>
-              <AsyncChild val="state.val"/>
-            </AsyncRoot>
-          </div>
-        </div>`;
-      static components = { Child, AsyncChild, AsyncRoot };
-      state = useState({ val: 0 });
-
-      updateApp() {
-        this.state.val++;
-      }
-    }
-
-    const parent = new Parent();
-    await parent.mount(fixture);
-
-    expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>0/0</span><span>0/0</span>");
-
-    // click on button to increment Parent counter
-    def = makeDeferred();
-    fixture.querySelector("button")!.click();
-    await nextTick();
-
-    expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>0/1</span><span>0/0</span>");
-
-    // click on each Child to increment their local counter
-    const children = parent.el!.querySelectorAll("span");
-    children[0]!.click();
-    await nextTick();
-    expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>1/1</span><span>0/0</span>");
-
-    children[1]!.click();
-    await nextTick();
-    expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>1/1</span><span>0/0</span>");
-
-    // finalize first re-rendering (coming from the props update)
-    def.resolve();
-    await nextTick();
-
-    expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>1/1</span><span>1/1</span>");
-  });
-});
@@ -1,6 +1,5 @@
 import { QWeb } from "../../src/qweb/index";
-import { nextTick, normalize, renderToDOM, renderToString, trim } from "../helpers";
-import { patch } from "../../src/vdom";
+import { normalize, renderToDOM, renderToString, trim, nextTick } from "../helpers";

 //------------------------------------------------------------------------------
 // Setup and helpers
@@ -51,9 +50,9 @@ describe("static templates", () => {
    expect(renderToString(qweb, "test")).toBe("<div><span>word</span></div>");
  });

-  test("properly handle comments", () => {
+  test("ignore comments", () => {
    qweb.addTemplate("test", "<div>hello <!-- comment-->owl</div>");
-    expect(renderToString(qweb, "test")).toBe("<div>hello <!-- comment-->owl</div>");
+    expect(renderToString(qweb, "test")).toBe("<div>hello owl</div>");
  });
 });

@@ -80,12 +79,19 @@ describe("error handling", () => {
    expect(() => qweb.addTemplate("test", "<div/>")).toThrow("already defined");
  });

-  test("addTemplates throw if parser error", () => {
+  test("loadTemplates throw if parser error", () => {
    expect(() => {
      qweb.addTemplates("<templates><abc>></templates>");
    }).toThrow("Invalid XML in template");
  });

+  test("nice error when t-on-directive is evaluated with a missing handler", () => {
+    qweb.addTemplate("templatename", `<div t-on-click="somemethod"></div>`);
+    expect(() => qweb.render("templatename", {}, { handlers: [] })).toThrow(
+      "Missing handler 'somemethod' when evaluating template 'templatename'"
+    );
+  });
+
  test("nice error when t-on is evaluated with a missing event", () => {
    qweb.addTemplate("templatename", `<div t-on="somemethod"></div>`);
    expect(() => qweb.render("templatename", { someMethod() {} }, { handlers: [] })).toThrow(
@@ -322,61 +328,6 @@ describe("t-if", () => {
    };
    expect(normalize(renderToString(qweb, "test", context))).toBe("<div>andormgtnlt</div>");
  });
-
-  test("t-esc with t-if", () => {
-    qweb.addTemplate("test", `<div><t t-if="true" t-esc="'x'"/></div>`);
-    expect(renderToString(qweb, "test")).toBe("<div>x</div>");
-  });
-
-  test("t-esc with t-elif", () => {
-    qweb.addTemplate("test", `<div><t t-if="false">abc</t><t t-else="1" t-esc="'x'"/></div>`);
-    expect(renderToString(qweb, "test")).toBe("<div>x</div>");
-  });
-
-  test("t-set, then t-if", () => {
-    qweb.addTemplate(
-      "test",
-      `
-      <div>
-        <t t-set="title" t-value="'test'"/>
-        <t t-if="title"><t t-esc="title"/></t>
-      </div>`
-    );
-    const result = renderToString(qweb, "test");
-    const expected = `<div>test</div>`;
-    expect(result).toBe(expected);
-  });
-
-  test("t-set, then t-if, part 2", () => {
-    qweb.addTemplate(
-      "test",
-      `
-        <div>
-            <t t-set="y" t-value="true"/>
-            <t t-set="x" t-value="y"/>
-            <span t-if="x">COUCOU</span>
-        </div>`
-    );
-    const result = renderToString(qweb, "test");
-    const expected = `<div><span>COUCOU</span></div>`;
-    expect(result).toBe(expected);
-  });
-
-  test("t-set, then t-elif, part 3", () => {
-    qweb.addTemplate(
-      "test",
-      `
-        <div>
-            <t t-set="y" t-value="false"/>
-            <t t-set="x" t-value="y"/>
-            <span t-if="x">AAA</span>
-            <span t-elif="!x">BBB</span>
-        </div>`
-    );
-    const result = renderToString(qweb, "test");
-    const expected = `<div><span>BBB</span></div>`;
-    expect(result).toBe(expected);
-  });
 });

 describe("attributes", () => {
@@ -660,7 +611,7 @@ describe("t-call (template calling", () => {
    `);
    const expected = "<div><span>hey</span></div>";
    expect(renderToString(qweb, "recursive")).toBe(expected);
-    const recursiveFn = Object.values(qweb.recursiveFns)[0] as any;
+    const recursiveFn = Object.values(qweb.recursiveFns)[0];
    expect(recursiveFn.toString()).toMatchSnapshot();
  });

@@ -688,7 +639,7 @@ describe("t-call (template calling", () => {
    expect(renderToString(qweb, "Parent", { root }, { fiber: { vars: {}, scope: {} } })).toBe(
      expected
    );
-    const recursiveFn = Object.values(qweb.recursiveFns)[0] as any;
+    const recursiveFn = Object.values(qweb.recursiveFns)[0];
    expect(recursiveFn.toString()).toMatchSnapshot();
  });

@@ -715,7 +666,7 @@ describe("t-call (template calling", () => {
    const expected =
      "<div><div><p>a</p><div><p>b</p><div><p>d</p></div></div><div><p>c</p></div></div></div>";
    expect(renderToString(qweb, "Parent", { root }, { fiber: {} })).toBe(expected);
-    const recursiveFn = Object.values(qweb.recursiveFns)[0] as any;
+    const recursiveFn = Object.values(qweb.recursiveFns)[0];
    expect(recursiveFn.toString()).toMatchSnapshot();
  });

@@ -798,23 +749,6 @@ describe("foreach", () => {
    expect(Object.keys(context).length).toBe(0);
  });

-  test("t-foreach in t-forach", () => {
-    qweb.addTemplate(
-      "test",
-      `<div>
-        <t t-foreach="numbers" t-as="number">
-          <t t-foreach="letters" t-as="letter">
-            [<t t-esc="number"/><t t-esc="letter"/>]
-          </t>
-        </t>
-      </div>`
-    );
-    const context = { numbers: [1, 2, 3], letters: ["a", "b"] };
-    expect(renderToString(qweb, "test", context)).toBe(
-      "<div> [1a]  [1b]  [2a]  [2b]  [3a]  [3b] </div>"
-    );
-  });
-
  test("throws error if invalid loop expression", () => {
    qweb.addTemplate(
      "test",
@@ -838,16 +772,13 @@ describe("foreach", () => {
    );
    renderToString(qweb, "test");
    expect(console.warn).toHaveBeenCalledTimes(1);
-    expect(console.warn).toHaveBeenCalledWith(
-      "Directive t-foreach should always be used with a t-key! (in template: 'test')"
-    );
    console.warn = consoleWarn;
  });
 });

 describe("misc", () => {
  test("global", () => {
-    qweb.addTemplate("_callee-asc", `<año t-att-falló="'agüero'" t-raw="0"/>`);
+    qweb.addTemplate("_callee-asc", `<Año t-att-falló="'agüero'" t-raw="0"/>`);
    qweb.addTemplate("_callee-uses-foo", `<span t-esc="foo">foo default</span>`);
    qweb.addTemplate("_callee-asc-toto", `<div t-raw="toto">toto default</div>`);
    qweb.addTemplate(
@@ -1044,35 +975,6 @@ describe("t-on", () => {
    (<HTMLElement>node).click();
  });

-  test("t-on with inline statement", () => {
-    qweb.addTemplate("test", `<button t-on-click="state.counter++">Click</button>`);
-    let owner = {
-      state: {
-        counter: 0
-      }
-    };
-    const node = renderToDOM(qweb, "test", owner, { handlers: [] });
-    expect(owner.state.counter).toBe(0);
-    (<HTMLElement>node).click();
-    expect(owner.state.counter).toBe(1);
-  });
-
-  test("t-on with inline statement (function call)", () => {
-    qweb.addTemplate("test", `<button t-on-click="state.incrementCounter(2)">Click</button>`);
-    let owner = {
-      state: {
-        counter: 0,
-        incrementCounter: inc => {
-          owner.state.counter += inc;
-        }
-      }
-    };
-    const node = renderToDOM(qweb, "test", owner, { handlers: [] });
-    expect(owner.state.counter).toBe(0);
-    (<HTMLElement>node).click();
-    expect(owner.state.counter).toBe(2);
-  });
-
  test("t-on with prevent and/or stop modifiers", async () => {
    expect.assertions(7);
    qweb.addTemplate(
@@ -1184,96 +1086,6 @@ describe("t-on", () => {

    expect(steps).toEqual([true, true]);
  });
-
-  test("t-on with prevent modifier in t-foreach", async () => {
-    expect.assertions(5);
-    qweb.addTemplate(
-      "test",
-      `<div>
-        <t t-foreach="projects" t-as="project">
-          <a href="#" t-key="project" t-on-click.prevent="onEdit(project.id)">
-            Edit <t t-esc="project.name"/>
-          </a>
-        </t>
-      </div>`
-    );
-    const steps: string[] = [];
-    const owner = {
-      projects: [{ id: 1, name: "Project 1" }, { id: 2, name: "Project 2" }],
-
-      onEdit(projectId, ev) {
-        expect(ev.defaultPrevented).toBe(true);
-        steps.push(projectId);
-      }
-    };
-
-    const node = <HTMLElement>renderToDOM(qweb, "test", owner, { handlers: [] });
-    expect(node.outerHTML).toBe(
-      `<div><a href="#"> Edit Project 1</a><a href="#"> Edit Project 2</a></div>`
-    );
-
-    const links = node.querySelectorAll("a")!;
-    links[0].click();
-    links[1].click();
-
-    expect(steps).toEqual([1, 2]);
-  });
-
-  test("t-on with empty handler (only modifiers)", () => {
-    expect.assertions(2);
-    qweb.addTemplate(
-      "test",
-      `<div>
-        <button t-on-click.prevent="">Button</button>
-      </div>`
-    );
-    const node = renderToDOM(qweb, "test", {}, { handlers: [] });
-
-    node.addEventListener("click", e => {
-      expect(e.defaultPrevented).toBe(true);
-    });
-
-    const button = (<HTMLElement>node).getElementsByTagName("button")[0];
-    button.click();
-  });
-
-  test("t-on combined with t-esc", async () => {
-    expect.assertions(3);
-    qweb.addTemplate("test", `<div><button t-on-click="onClick" t-esc="text"/></div>`);
-    const steps: string[] = [];
-    const owner = {
-      text: "Click here",
-      onClick() {
-        steps.push("onClick");
-      }
-    };
-
-    const node = <HTMLElement>renderToDOM(qweb, "test", owner, { handlers: [] });
-    expect(node.outerHTML).toBe(`<div><button>Click here</button></div>`);
-
-    node.querySelector("button")!.click();
-
-    expect(steps).toEqual(["onClick"]);
-  });
-
-  test("t-on combined with t-raw", async () => {
-    expect.assertions(3);
-    qweb.addTemplate("test", `<div><button t-on-click="onClick" t-raw="html"/></div>`);
-    const steps: string[] = [];
-    const owner = {
-      html: "Click <b>here</b>",
-      onClick() {
-        steps.push("onClick");
-      }
-    };
-
-    const node = <HTMLElement>renderToDOM(qweb, "test", owner, { handlers: [] });
-    expect(node.outerHTML).toBe(`<div><button>Click <b>here</b></button></div>`);
-
-    node.querySelector("button")!.click();
-
-    expect(steps).toEqual(["onClick"]);
-  });
 });

 describe("t-ref", () => {
@@ -1309,12 +1121,12 @@ describe("t-ref", () => {

 describe("loading templates", () => {
  test("can initialize qweb with a string", () => {
-    const templates = `
+    const data = `
      <?xml version="1.0" encoding="UTF-8"?>
      <templates id="template" xml:space="preserve">
        <div t-name="hey">jupiler</div>
      </templates>`;
-    const qweb = new QWeb({ templates });
+    const qweb = new QWeb(data);
    expect(renderToString(qweb, "hey")).toBe("<div>jupiler</div>");
  });

@@ -1523,84 +1335,3 @@ describe("properly support svg", () => {
    );
  });
 });
-
-describe("translation support", () => {
-  test("can translate node content", () => {
-    const translations = {
-      word: "mot"
-    };
-    const translateFn = expr => translations[expr] || expr;
-    const qweb = new QWeb({ translateFn });
-    qweb.addTemplate("test", "<div>word</div>");
-    expect(renderToString(qweb, "test")).toBe("<div>mot</div>");
-  });
-
-  test("does not translate node content if disabled", () => {
-    const translations = {
-      word: "mot"
-    };
-    const translateFn = expr => translations[expr] || expr;
-    const qweb = new QWeb({ translateFn });
-    qweb.addTemplate(
-      "test",
-      `
-      <div>
-        <span>word</span>
-        <span t-translation="off">word</span>
-      </div>`
-    );
-    expect(renderToString(qweb, "test")).toBe("<div><span>mot</span><span>word</span></div>");
-  });
-
-  test("some attributes are translated", () => {
-    const translations = {
-      word: "mot"
-    };
-    const translateFn = expr => translations[expr] || expr;
-    const qweb = new QWeb({ translateFn });
-    qweb.addTemplate(
-      "test",
-      `
-      <div>
-        <p label="word">word</p>
-        <p title="word">word</p>
-        <p placeholder="word">word</p>
-        <p alt="word">word</p>
-        <p something="word">word</p>
-      </div>`
-    );
-    expect(renderToString(qweb, "test")).toBe(
-      '<div><p label="mot">mot</p><p title="mot">mot</p><p placeholder="mot">mot</p><p alt="mot">mot</p><p something="word">mot</p></div>'
-    );
-  });
-});
-
-describe("t-key tests", () => {
-  test("t-key on t-foreach", async () => {
-    qweb.addTemplate(
-      "test",
-      `
-        <div>
-          <t t-foreach="things" t-as="thing" t-key="thing">
-            <span/>
-          </t>
-        </div>`
-    );
-
-    let vnode = qweb.render("test", { things: [1, 2] });
-    vnode = patch(document.createElement("div"), vnode);
-    let elm = vnode.elm as HTMLElement;
-
-    expect(elm.outerHTML).toBe("<div><span></span><span></span></div>");
-
-    const first = elm.querySelectorAll("span")[0];
-    const second = elm.querySelectorAll("span")[1];
-
-    patch(vnode, qweb.render("test", { things: [2, 1] }));
-
-    expect(elm.outerHTML).toBe("<div><span></span><span></span></div>");
-
-    expect(first).toBe(elm.querySelectorAll("span")[1]);
-    expect(second).toBe(elm.querySelectorAll("span")[0]);
-  });
-});
@@ -1,9 +1,8 @@
 import { Component } from "../../src/component/component";
-import { config } from "../../src/config";
-import { Link } from "../../src/router/link";
-import { RouterEnv } from "../../src/router/router";
+import { Link } from "../../src/router/Link";
+import { RouterEnv } from "../../src/router/Router";
 import { makeTestEnv, makeTestFixture, nextTick } from "../helpers";
-import { TestRouter } from "./test_router";
+import { TestRouter } from "./TestRouter";

 describe("Link component", () => {
  let fixture: HTMLElement;
@@ -13,7 +12,6 @@ describe("Link component", () => {
  beforeEach(() => {
    fixture = makeTestFixture();
    env = <RouterEnv>makeTestEnv();
-    config.env = env;
  });

  afterEach(() => {
@@ -40,7 +38,7 @@ describe("Link component", () => {

    router = new TestRouter(env, routes, { mode: "history" });
    router.navigate({ to: "users" });
-    const app = new App();
+    const app = new App(env);
    await app.mount(fixture);
    expect(fixture.innerHTML).toBe('<div><a href="/about">About</a></div>');

@@ -71,7 +69,7 @@ describe("Link component", () => {

    router = new TestRouter(env, routes, { mode: "history" });
    router.navigate({ to: "users" });
-    const app = new App();
+    const app = new App(env);
    await app.mount(fixture);

    expect(window.location.pathname).toBe("/users");
@@ -1,9 +1,8 @@
 import { Component } from "../../src/component/component";
-import { config } from "../../src/config";
-import { RouterEnv } from "../../src/router/router";
-import { RouteComponent } from "../../src/router/route_component";
+import { RouterEnv } from "../../src/router/Router";
+import { RouteComponent } from "../../src/router/RouteComponent";
 import { makeTestEnv, makeTestFixture, nextTick } from "../helpers";
-import { TestRouter } from "./test_router";
+import { TestRouter } from "./TestRouter";

 describe("RouteComponent", () => {
  let fixture: HTMLElement;
@@ -13,7 +12,6 @@ describe("RouteComponent", () => {
  beforeEach(() => {
    fixture = makeTestFixture();
    env = <RouterEnv>makeTestEnv();
-    config.env = env;
  });

  afterEach(() => {
@@ -47,7 +45,7 @@ describe("RouteComponent", () => {

    router = new TestRouter(env, routes, { mode: "history" });
    await router.navigate({ to: "about" });
-    const app = new App();
+    const app = new App(env);
    await app.mount(fixture);
    expect(fixture.innerHTML).toBe("<div><span>About</span></div>");

@@ -74,7 +72,7 @@ describe("RouteComponent", () => {
    const routes = [{ name: "book", path: "/book/{{title}}", component: Book }];
    router = new TestRouter(env, routes, { mode: "history" });
    await router.navigate({ to: "book", params: { title: "1984" } });
-    const app = new App();
+    const app = new App(env);
    await app.mount(fixture);
    expect(fixture.innerHTML).toBe("<div><span>Book 1984</span></div>");
  });
@@ -100,7 +98,7 @@ describe("RouteComponent", () => {
    const routes = [{ name: "book", path: "/book/{{title}}/{{val.number}}", component: Book }];
    router = new TestRouter(env, routes, { mode: "history" });
    await router.navigate({ to: "book", params: { title: "1984", val: "123" } });
-    const app = new App();
+    const app = new App(env);
    await app.mount(fixture);
    expect(fixture.innerHTML).toBe("<div><span>Book 1984|124</span></div>");
  });
@@ -1,4 +1,4 @@
-import { Router } from "../../src/router/router";
+import { Router } from "../../src/router/Router";
 import { QWeb } from "../../src/qweb/index";

 export class TestRouter extends Router {
@@ -5,13 +5,16 @@ exports[`Link component can render simple cases 1`] = `
 ) {
    let utils = this.constructor.utils;
    let owner = context;
-    let sibling = null;
    var h = this.h;
    let _1 = utils.toObj({'router-link-active':context['isActive']});
    var _2 = context['href'];
    let c3 = [], p3 = {key:3,attrs:{href: _2},class:_1,on:{}};
    var vn3 = h('a', p3, c3);
-    extra.handlers['click' + 3] = extra.handlers['click' + 3] || function (e) {const fn = context['navigate'];if (fn) { fn.call(owner, e); } else { context.navigate; }};
+    result = vn3;
+    if (!context['navigate']) {
+        throw new Error('Missing handler \\\\'' + 'navigate' + \`\\\\' when evaluating template '__template__1'\`)
+    }
+    extra.handlers['click' + 3] = extra.handlers['click' + 3] || context['navigate'].bind(owner);
    p3.on['click'] = extra.handlers['click' + 3];
    const slot4 = this.constructor.slots[context.__owl__.slotId + '_' + 'default'];
    if (slot4) {
@@ -0,0 +1,45 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`RouteComponent can render simple cases 1`] = `
+"function anonymous(context,extra
+) {
+    let utils = this.constructor.utils;
+    let QWeb = this.constructor;
+    let parent = context;
+    let owner = context;
+    let result;
+    var h = this.h;
+    if (context['routeComponent']) {
+        //COMPONENT
+        let key4 = 'key' + context['env'].router.currentRouteName;
+        let def2;
+        let templateId5 = key4;
+        let w3 = templateId5 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[templateId5]] : false;
+        let vn6 = {};
+        result = vn6;
+        let props3 = Object.assign({}, context['env'].router.currentParams);
+        if (w3 && w3.__owl__.currentFiber && !w3.__owl__.vnode) {
+            if (utils.shallowEqual(props3, w3.__owl__.currentFiber.props)) {
+                def2 = w3.__owl__.currentFiber.promise;
+            } else {
+                w3.destroy();
+                w3 = false;
+            }
+        }
+        if (!w3) {
+            let componentKey3 = \`routeComponent\`;
+            let W3 = context.constructor.components[componentKey3] || QWeb.components[componentKey3]|| context['routeComponent'];
+            if (!W3) {throw new Error('Cannot find the definition of component \\"' + componentKey3 + '\\"')}
+            w3 = new W3(parent, props3);
+            parent.__owl__.cmap[templateId5] = w3.__owl__.id;
+            def2 = w3.__prepare(extra.fiber, undefined, undefined);
+            def2 = def2.then(vnode=>{if (w3.__owl__.isDestroyed){return}let pvnode=h(vnode.sel, {key: templateId5, hook: {insert(vn) {let nvn=w3.__mount(vnode, pvnode.elm);pvnode.elm=nvn.elm;},remove() {},destroy(vn) {w3.destroy();}}});utils.defineProxy(vn6, pvnode);w3.__owl__.pvnode = pvnode;});
+        } else {
+            def2 = def2 || w3.__updateProps(props3, extra.fiber, undefined, undefined);
+            def2 = def2.then(()=>{if (w3.__owl__.isDestroyed) {return};let pvnode=w3.__owl__.pvnode;utils.defineProxy(vn6, pvnode);});
+        }
+        extra.promises.push(def2);
+    }
+    return result;
+}"
+`;
@@ -1,46 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`RouteComponent can render simple cases 1`] = `
-"function anonymous(context,extra
-) {
-    let utils = this.constructor.utils;
-    let QWeb = this.constructor;
-    let parent = context;
-    let owner = context;
-    let sibling = null;
-    let result;
-    var h = this.h;
-    if (context['routeComponent']) {
-        const nodeKey1 = context['env'].router.currentRouteName;
-        //COMPONENT
-        let templateId3 = \`__4__\` + nodeKey1;
-        let w3 = templateId3 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[templateId3]] : false;
-        let vn5 = {};
-        result = vn5;
-        let props3 = Object.assign({}, context['env'].router.currentParams);
-        if (w3 && w3.__owl__.currentFiber && !w3.__owl__.vnode) {
-            w3.destroy();
-            w3 = false;
-        }
-        if (w3) {
-            w3.__updateProps(props3, extra.fiber, undefined, undefined, sibling);
-            let pvnode = w3.__owl__.pvnode;
-            utils.defineProxy(vn5, pvnode);
-        } else {
-            let componentKey3 = \`routeComponent\`;
-            let W3 = context.constructor.components[componentKey3] || QWeb.components[componentKey3]|| context['routeComponent'];
-            if (!W3) {throw new Error('Cannot find the definition of component \\"' + componentKey3 + '\\"')}
-            w3 = new W3(parent, props3);
-            parent.__owl__.cmap[templateId3] = w3.__owl__.id;
-            let def2 = w3.__prepare(extra.fiber, undefined, undefined, sibling);
-            let pvnode = h('dummy', {key: templateId3, hook: {insert(vn) { let nvn=w3.__mount(fiber, pvnode.elm);pvnode.elm=nvn.elm;},remove() {},destroy(vn) {w3.destroy();}}});
-            const fiber = w3.__owl__.currentFiber;
-            def2.then(function () {if (w3.__owl__.isDestroyed) {return;} const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
-            utils.defineProxy(vn5, pvnode);
-            w3.__owl__.pvnode = pvnode;
-        }
-        sibling = w3.__owl__.currentFiber || sibling;
-    }
-    return result;
-}"
-`;
@@ -1,6 +1,6 @@
-import { Destination, RouterEnv, Route } from "../../src/router/router";
+import { Destination, RouterEnv, Route } from "../../src/router/Router";
 import { makeTestEnv, nextTick } from "../helpers";
-import { TestRouter } from "./test_router";
+import { TestRouter } from "./TestRouter";

 let env: RouterEnv;
 let router: TestRouter | null = null;
@@ -52,14 +52,6 @@ describe("router miscellaneous", () => {
    expect(window.location.hash).toBe("#/users/5");
    expect(env.qweb.forceUpdate).toHaveBeenCalledTimes(2);
  });
-
-  test("navigate in hash mode preserve location", async () => {
-    router = new TestRouter(env, [{ name: "users", path: "/users/{{id}}" }], { mode: "hash" });
-    window.history.pushState({}, "title", window.location.origin + "/test.html");
-    expect(window.location.href).toBe("http://localhost/test.html");
-    await router.navigate({ to: "users", params: { id: 3 } });
-    expect(window.location.href).toBe("http://localhost/test.html#/users/3");
-  });
 });

 describe("routeToPath", () => {
@@ -0,0 +1,21 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`connecting a component to store connecting a component to a local store 1`] = `"<div></div>"`;
+
+exports[`connecting a component to store connecting a component to a local store 2`] = `"<div><span>hello</span></div>"`;
+
+exports[`connecting a component to store connecting a component works 1`] = `"<div></div>"`;
+
+exports[`connecting a component to store connecting a component works 2`] = `"<div><span>hello</span></div>"`;
+
+exports[`connecting a component to store deep and shallow connecting a component 1`] = `"<div><span>Kasteel</span></div>"`;
+
+exports[`connecting a component to store deep and shallow connecting a component 2`] = `"<div><span>Kasteel</span></div>"`;
+
+exports[`connecting a component to store deep and shallow connecting a component 3`] = `"<div><span>Bertinchamps</span></div>"`;
+
+exports[`connecting a component to store deep and shallow connecting a component 4`] = `"<div><span>Kasteel</span></div>"`;
+
+exports[`various scenarios scenarios with async store updates and some components events 1`] = `"<div><button>Do stuff</button><div><span>Attachment 100</span><span>Name: text.txt</span></div></div>"`;
+
+exports[`various scenarios scenarios with async store updates and some components events 2`] = `"<div><button>Do stuff</button></div>"`;
@@ -1,6 +1,6 @@
-import { Env } from "../src/component/component";
-import { Store, Getter } from "../src/store";
-import { nextTick, nextMicroTick } from "./helpers";
+import { Env } from "../../src/component/component";
+import { Store, Getter } from "../../src/store/store";
+import { nextTick, nextMicroTick } from "../helpers";

 describe("basic use", () => {
  test("dispatch an action", () => {
@@ -1,994 +0,0 @@
-import { Component, Env } from "../src/component/component";
-import { config } from "../src/config";
-import { Store, useStore, useDispatch, useGetters } from "../src/store";
-import { useState } from "../src/hooks";
-import { xml } from "../src/tags";
-import { shallowEqual } from "../src/utils";
-import { makeTestEnv, makeTestFixture, nextTick, makeDeferred } from "./helpers";
-
-describe("connecting a component to store", () => {
-  let fixture: HTMLElement;
-  let env: Env;
-
-  beforeEach(() => {
-    fixture = makeTestFixture();
-    env = makeTestEnv();
-    config.env = env;
-  });
-
-  afterEach(() => {
-    fixture.remove();
-  });
-
-  test("connecting a component works, with useStore", async () => {
-    let nextId = 1;
-    const state = { todos: [] };
-    const actions = {
-      addTodo({ state }, msg) {
-        state.todos.push({ msg, id: nextId++ });
-      }
-    };
-    const store = new Store({ state, actions });
-
-    class App extends Component<any, any> {
-      static template = xml`
-            <div>
-                <span t-foreach="todos" t-key="todo.id" t-as="todo"><t t-esc="todo.msg"/></span>
-            </div>`;
-      todos = useStore(state => state.todos);
-    }
-
-    (<any>env).store = store;
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div></div>");
-
-    await store.dispatch("addTodo", "hello");
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>hello</span></div>");
-  });
-
-  test("can use useStore twice in a component", async () => {
-    const state = { a: 1, b: 2 };
-    const actions = {
-      doSomething({ state }) {
-        state.a = 2;
-        state.b = 3;
-      }
-    };
-    const store = new Store({ state, actions });
-
-    class App extends Component<any, any> {
-      static template = xml`
-            <div>
-                <span t-esc="a.value"/>
-                <span t-esc="b.value"/>
-            </div>`;
-      a = useStore(state => ({ value: state.a }));
-      b = useStore(state => ({ value: state.b }));
-    }
-    App.prototype.__render = jest.fn(App.prototype.__render);
-
-    (<any>env).store = store;
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>1</span><span>2</span></div>");
-    expect(App.prototype.__render).toBeCalledTimes(1);
-
-    await store.dispatch("doSomething");
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>2</span><span>3</span></div>");
-    expect(App.prototype.__render).toBeCalledTimes(2);
-  });
-
-  test("useStore: do not re-render if not changed", async () => {
-    let nextId = 1;
-    const state = { todos: [], a: 1 };
-    const actions = {
-      addTodo({ state }, msg) {
-        state.todos.push({ msg, id: nextId++ });
-      }
-    };
-    const store = new Store({ state, actions });
-
-    class App extends Component<any, any> {
-      static template = xml`
-            <div>
-                <span t-foreach="todos" t-key="todo.id" t-as="todo"><t t-esc="todo.msg"/></span>
-            </div>`;
-      todos = useStore(state => state.todos);
-    }
-    App.prototype.__render = jest.fn(App.prototype.__render);
-
-    (<any>env).store = store;
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div></div>");
-    expect(App.prototype.__render).toBeCalledTimes(1);
-
-    store.state.todos.push({ id: 3, msg: "hello" });
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>hello</span></div>");
-    expect(App.prototype.__render).toBeCalledTimes(2);
-
-    store.state.a = 2;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>hello</span></div>");
-    expect(App.prototype.__render).toBeCalledTimes(2);
-  });
-
-  test("connecting a component with useStore returning number", async () => {
-    let nextId = 1;
-    const state = { todos: [] };
-    const actions = {
-      addTodo({ state }, msg) {
-        state.todos.push({ msg, id: nextId++ });
-      }
-    };
-    const store = new Store({ state, actions });
-
-    class App extends Component<any, any> {
-      static template = xml`<div><t t-esc="nbrTodos.value"/></div>`;
-      nbrTodos = useStore(state => ({ value: state.todos.length }));
-    }
-
-    (<any>env).store = store;
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div>0</div>");
-
-    await store.dispatch("addTodo", "hello");
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div>1</div>");
-  });
-
-  test("connecting a component with useStore returning number", async () => {
-    let nextId = 1;
-    const state = { todos: [], a: 1 };
-    const actions = {
-      addTodo({ state }, msg) {
-        state.todos.push({ msg, id: nextId++ });
-      },
-      incrementA({ state }) {
-        state.a++;
-      }
-    };
-    const store = new Store({ state, actions });
-    class App extends Component<any, any> {
-      static template = xml`<div><t t-esc="nbrTodos.value"/></div>`;
-      nbrTodos = useStore(state => ({ value: state.todos.length }), { isEqual: shallowEqual });
-    }
-    App.prototype.__render = jest.fn(App.prototype.__render);
-
-    (<any>env).store = store;
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div>0</div>");
-    expect(App.prototype.__render).toBeCalledTimes(1);
-
-    await store.dispatch("addTodo", "hello");
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div>1</div>");
-    expect(App.prototype.__render).toBeCalledTimes(2);
-
-    await store.dispatch("incrementA");
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div>1</div>");
-    expect(App.prototype.__render).toBeCalledTimes(2);
-  });
-
-  test("connecting a component to a local store", async () => {
-    let nextId = 1;
-    const state = { todos: [] };
-    const actions = {
-      addTodo({ state }, msg) {
-        state.todos.push({ msg, id: nextId++ });
-      }
-    };
-    const store = new Store({ state, actions });
-
-    class App extends Component<any, any> {
-      static template = xml`
-            <div>
-                <span t-foreach="todos" t-key="todo.id" t-as="todo"><t t-esc="todo.msg"/></span>
-            </div>`;
-      todos = useStore(state => state.todos, { store });
-    }
-
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div></div>");
-
-    await store.dispatch("addTodo", "hello");
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>hello</span></div>");
-  });
-
-  test("can dispatch actions from a connected component", async () => {
-    const store = new Store({
-      state: { value: 1 },
-      actions: {
-        inc({ state }) {
-          state.value++;
-        }
-      }
-    });
-    (<any>env).store = store;
-
-    class App extends Component<any, any> {
-      static template = xml`
-          <div>
-              <button t-on-click="dispatch('inc')">Inc</button>
-              <span><t t-esc="storeState.value"/></span>
-          </div>`;
-      storeState = useStore(state => state);
-      dispatch = useDispatch();
-    }
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><button>Inc</button><span>1</span></div>");
-
-    fixture.querySelector("button")!.click();
-    await nextTick();
-
-    expect(fixture.innerHTML).toBe("<div><button>Inc</button><span>2</span></div>");
-  });
-
-  test("useStore can use props", async () => {
-    const state = { todos: [{ id: 1, text: "jupiler" }, { id: 2, text: "chimay" }] };
-    const store = new Store({ state, actions: {} });
-
-    class TodoItem extends Component<any, any> {
-      static template = xml`<span><t t-esc="todo.text"/></span>`;
-      todo = useStore((state, props) => {
-        return state.todos.find(t => t.id === props.todoId);
-      });
-    }
-
-    class App extends Component<any, any> {
-      static template = xml`<div><TodoItem todoId="state.currentId"/></div>`;
-      static components = { TodoItem };
-      state = useState({ currentId: 1 });
-    }
-
-    (<any>env).store = store;
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>jupiler</span></div>");
-
-    app.state.currentId = 2;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>chimay</span></div>");
-  });
-
-  test("useStore receives props as second argument", async () => {
-    const state = { todos: [{ id: 1, text: "jupiler" }] };
-    let nextId = 2;
-    const actions = {
-      addTodo({ state }, text) {
-        state.todos.push({ text, id: nextId++ });
-      }
-    };
-    const store = new Store({ state, actions });
-
-    class TodoItem extends Component<any, any> {
-      static template = xml`<span><t t-esc="todo.text"/></span>`;
-      todo = useStore((state, props) => {
-        return state.todos.find(t => t.id === props.id);
-      });
-    }
-
-    class TodoList extends Component<any, any> {
-      static template = xml`
-        <div>
-          <TodoItem t-foreach="todos" t-as="todo" id="todo.id" t-key="todo.id"/>
-        </div>`;
-      static components = { TodoItem };
-      todos = useStore(state => state.todos);
-    }
-
-    (<any>env).store = store;
-    const app = new TodoList();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>jupiler</span></div>");
-
-    store.dispatch("addTodo", "hoegaarden");
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>jupiler</span><span>hoegaarden</span></div>");
-  });
-
-  test("can call useGetters to receive store getters", async () => {
-    const state = {
-      importantID: 1,
-      todos: [{ id: 1, text: "jupiler" }, { id: 2, text: "bertinchamps" }]
-    };
-    const getters = {
-      importantTodoText({ state }) {
-        return state.todos.find(todo => todo.id === state.importantID).text;
-      },
-      text({ state }, id) {
-        return state.todos.find(todo => todo.id === id).text;
-      }
-    };
-    const store = new Store({ state, getters });
-
-    class TodoItem extends Component<any, any> {
-      static template = xml`
-        <div>
-          <span><t t-esc="storeProps.activeTodoText"/></span>
-          <span><t t-esc="storeProps.importantTodoText"/></span>
-        </div>`;
-      getters = useGetters();
-      storeProps = useStore((state, props) => {
-        const todo = state.todos.find(t => t.id === props.id);
-        return {
-          activeTodoText: this.getters.text(todo.id),
-          importantTodoText: this.getters.importantTodoText()
-        };
-      });
-    }
-
-    class TodoList extends Component<any, any> {
-      static components = { TodoItem };
-      static template = xml`
-        <div>
-          <t t-foreach="todos" t-as="todo">
-            <TodoItem id="todo.id" t-key="todo.id"/>
-          </t>
-        </div>`;
-      todos = useStore(state => state.todos);
-    }
-
-    (<any>env).store = store;
-    const app = new TodoList();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe(
-      "<div><div><span>jupiler</span><span>jupiler</span></div><div><span>bertinchamps</span><span>jupiler</span></div></div>"
-    );
-  });
-
-  test("connected component is updated when props are updated", async () => {
-    class Beer extends Component<any, any> {
-      static template = xml`<span><t t-esc="beer.name"/></span>`;
-      beer = useStore((state, props) => state.beers[props.id]);
-    }
-
-    class App extends Component<any, any> {
-      static template = xml`<div><Beer id="state.beerId"/></div>`;
-      static components = { Beer };
-      state = useState({ beerId: 1 });
-    }
-
-    const state = { beers: { 1: { name: "jupiler" }, 2: { name: "kwak" } } };
-    const store = new Store({ state });
-    (<any>env).store = store;
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>jupiler</span></div>");
-
-    app.state.beerId = 2;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>kwak</span></div>");
-  });
-
-  test("connected component is updated when store is changed", async () => {
-    class App extends Component<any, any> {
-      static template = xml`
-        <div>
-            <span t-foreach="data.beers" t-as="beer" t-key="beer.name"><t t-esc="beer.name"/></span>
-        </div>`;
-
-      // we have here a new object
-      data = useStore(state => ({ beers: state.beers, otherKey: 1 }));
-    }
-
-    const actions = {
-      addBeer({ state }, name) {
-        state.beers.push({ name });
-      }
-    };
-
-    const state = { beers: [{ name: "jupiler" }] };
-    const store = new Store({ state, actions });
-    (<any>env).store = store;
-
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>jupiler</span></div>");
-
-    store.dispatch("addBeer", "kwak");
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>jupiler</span><span>kwak</span></div>");
-  });
-
-  test("connected component with undefined, null and string props", async () => {
-    class Beer extends Component<any, any> {
-      static template = xml`
-            <div t-name="Beer">
-                <span>taster:<t t-esc="data.taster"/></span>
-                <span t-if="data.selected">selected:<t t-esc="data.selected.name"/></span>
-                <span t-if="data.consumed">consumed:<t t-esc="data.consumed.name"/></span>
-            </div>`;
-      data = useStore((state, props) => ({
-        selected: state.beers[props.id],
-        consumed: state.beers[state.consumedID] || null,
-        taster: state.taster
-      }));
-    }
-
-    class App extends Component<any, any> {
-      static template = xml`<div><Beer id="state.beerId"/></div>`;
-      static components = { Beer };
-      state = useState({ beerId: 0 });
-    }
-
-    const actions = {
-      consume({ state }, beerId) {
-        state.consumedID = beerId;
-      }
-    };
-    const state = {
-      beers: {
-        1: { name: "jupiler" }
-      },
-      consumedID: null,
-      taster: "aaron"
-    };
-    const store = new Store({ state, actions });
-    (<any>env).store = store;
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><div><span>taster:aaron</span></div></div>");
-
-    app.state.beerId = 1;
-    await nextTick();
-    expect(fixture.innerHTML).toBe(
-      "<div><div><span>taster:aaron</span><span>selected:jupiler</span></div></div>"
-    );
-
-    store.dispatch("consume", 1);
-    await nextTick();
-    expect(fixture.innerHTML).toBe(
-      "<div><div><span>taster:aaron</span><span>selected:jupiler</span><span>consumed:jupiler</span></div></div>"
-    );
-
-    app.state.beerId = 0;
-    await nextTick();
-    expect(fixture.innerHTML).toBe(
-      "<div><div><span>taster:aaron</span><span>consumed:jupiler</span></div></div>"
-    );
-  });
-
-  test("connected component deeply reactive with undefined, null and string props", async () => {
-    class Beer extends Component<any, any> {
-      static template = xml`
-            <div>
-                <span>taster:<t t-esc="info.taster"/></span>
-                <span t-if="info.selected">selected:<t t-esc="info.selected.name"/></span>
-                <span t-if="info.consumed">consumed:<t t-esc="info.consumed.name"/></span>
-            </div>`;
-      info = useStore(function(state, props) {
-        return {
-          selected: state.beers[props.id],
-          consumed: state.beers[state.consumedID] || null,
-          taster: state.taster
-        };
-      });
-    }
-
-    class App extends Component<any, any> {
-      static template = xml`<div><Beer id="state.beerId"/></div>`;
-      static components = { Beer };
-      state = useState({ beerId: 0 });
-    }
-
-    const actions = {
-      changeTaster({ state }, newTaster) {
-        state.taster = newTaster;
-      },
-      consume({ state }, beerId) {
-        state.consumedID = beerId;
-      },
-      renameBeer({ state }, { beerId, name }) {
-        state.beers[beerId].name = name;
-      }
-    };
-    const state = {
-      beers: {
-        1: { name: "jupiler" }
-      },
-      consumedID: null,
-      taster: "aaron"
-    };
-    const store = new Store({ state, actions });
-    (<any>env).store = store;
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><div><span>taster:aaron</span></div></div>");
-
-    app.state.beerId = 1;
-    await nextTick();
-    expect(fixture.innerHTML).toBe(
-      "<div><div><span>taster:aaron</span><span>selected:jupiler</span></div></div>"
-    );
-
-    store.dispatch("renameBeer", { beerId: 1, name: "kwak" });
-    await nextTick();
-    expect(fixture.innerHTML).toBe(
-      "<div><div><span>taster:aaron</span><span>selected:kwak</span></div></div>"
-    );
-
-    store.dispatch("consume", 1);
-    await nextTick();
-    expect(fixture.innerHTML).toBe(
-      "<div><div><span>taster:aaron</span><span>selected:kwak</span><span>consumed:kwak</span></div></div>"
-    );
-
-    app.state.beerId = 0;
-    await nextTick();
-    expect(fixture.innerHTML).toBe(
-      "<div><div><span>taster:aaron</span><span>consumed:kwak</span></div></div>"
-    );
-
-    store.dispatch("renameBeer", { beerId: 1, name: "jupiler" });
-    await nextTick();
-    expect(fixture.innerHTML).toBe(
-      "<div><div><span>taster:aaron</span><span>consumed:jupiler</span></div></div>"
-    );
-
-    store.dispatch("changeTaster", "matthieu");
-    await nextTick();
-    expect(fixture.innerHTML).toBe(
-      "<div><div><span>taster:matthieu</span><span>consumed:jupiler</span></div></div>"
-    );
-  });
-
-  test("correct update order when parent/children are connected", async () => {
-    const steps: string[] = [];
-
-    class Child extends Component<any, any> {
-      static template = xml`<span><t t-esc="state.msg"/></span>`;
-
-      state = useStore((state, props) => {
-        steps.push("child");
-        return { msg: state.msg[props.key] };
-      });
-    }
-    class Parent extends Component<any, any> {
-      static template = xml`<div><Child key="state.current"/></div>`;
-      static components = { Child };
-
-      state = useStore(state => {
-        steps.push("parent");
-        return {
-          current: state.current,
-          isvisible: state.isvisible
-        };
-      });
-    }
-
-    const state = { current: "a", msg: { a: "a", b: "b" } };
-    const actions = {
-      setCurrent({ state }, c) {
-        state.current = c;
-      }
-    };
-
-    const store = new Store({ state, actions });
-    (<any>env).store = store;
-    const app = new Parent();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>a</span></div>");
-    expect(steps).toEqual(["parent", "child"]);
-
-    store.dispatch("setCurrent", "b");
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>b</span></div>");
-    expect(steps).toEqual(["parent", "child", "parent", "child"]);
-  });
-
-  test("correct update order when parent/children are connected, part 2", async () => {
-    const steps: string[] = [];
-    let def = makeDeferred();
-    def.resolve();
-
-    class Child extends Component<any, any> {
-      static template = xml`<span><t t-esc="state.msg"/></span>`;
-      state = useStore((s, props) => {
-        steps.push("child");
-        return { msg: s.messages[props.someId] };
-      });
-    }
-
-    class Parent extends Component<any, any> {
-      static template = xml`
-            <div>
-                <Child t-if="state.flag" someId="state.someId"/>
-            </div>`;
-      static components = { Child };
-      state = useStore(s => {
-        steps.push("parent");
-        return { flag: s.flag, someId: s.someId };
-      });
-
-      async render(force) {
-        await def;
-        return super.render(force);
-      }
-    }
-
-    const state = { someId: 1, flag: true, messages: { 1: "abc" } };
-    const actions = {
-      setFlagToFalse({ state }) {
-        state.flag = false;
-      }
-    };
-
-    const store = new Store({ state, actions });
-    (<any>env).store = store;
-    const app = new Parent();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div><span>abc</span></div>");
-    expect(steps).toEqual(["parent", "child"]);
-
-    def = makeDeferred();
-    store.dispatch("setFlagToFalse");
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div><span>abc</span></div>");
-    expect(steps).toEqual(["parent", "child", "parent"]);
-
-    def.resolve();
-    await nextTick();
-    expect(steps).toEqual(["parent", "child", "parent"]);
-    expect(fixture.innerHTML).toBe("<div></div>");
-  });
-
-  test("connected parent/children: no double rendering", async () => {
-    let steps: string[] = [];
-    const actions = {
-      editTodo({ state }) {
-        state.todos[1].title = "abc";
-      }
-    };
-    const todos = { 1: { id: 1, title: "kikoou" } };
-    const state = {
-      todos
-    };
-    const store = new Store({
-      state,
-      actions
-    });
-
-    class TodoItem extends Component<any, any> {
-      static template = xml`
-            <div class="todo">
-                <t t-esc="state.todo.title"/>
-                <button class="destroy" t-on-click="editTodo">x</button>
-            </div>`;
-      state = useStore((state, props) => {
-        steps.push("item:usestore");
-        return {
-          todo: state.todos[props.id]
-        };
-      });
-
-      editTodo() {
-        this.env.store.dispatch("editTodo");
-      }
-      __render(f) {
-        steps.push("item:render");
-        return super.__render(f);
-      }
-    }
-    class TodoApp extends Component<any, any> {
-      static template = xml`
-            <div class="todoapp">
-                <t t-foreach="Object.values(state.todos)" t-as="todo">
-                    <TodoItem t-key="todo.id" id="todo.id"/>
-                </t>
-            </div>`;
-      static components = { TodoItem };
-      state = useStore(state => {
-        steps.push("app:usestore");
-        return { todos: state.todos };
-      });
-      __render(f) {
-        steps.push("app:render");
-        return super.__render(f);
-      }
-    }
-
-    (<any>env).store = store;
-    const app = new TodoApp();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe(
-      '<div class="todoapp"><div class="todo">kikoou<button class="destroy">x</button></div></div>'
-    );
-
-    expect(steps).toEqual(["app:usestore", "app:render", "item:usestore", "item:render"]);
-    steps = [];
-    fixture.querySelector("button")!.click();
-    await nextTick();
-    expect(steps).toEqual(["app:usestore", "app:render", "item:usestore", "item:render"]);
-    expect(fixture.innerHTML).toBe(
-      '<div class="todoapp"><div class="todo">abc<button class="destroy">x</button></div></div>'
-    );
-  });
-
-  test("connected parent/children: no rendering if child is destroyed", async () => {
-    let steps: string[] = [];
-    const actions = {
-      removeTodo({ state }) {
-        delete state.todos[1];
-      }
-    };
-    const todos = { 1: { id: 1, title: "kikoou" } };
-    const state = {
-      todos
-    };
-    const store = new Store({
-      state,
-      actions
-    });
-
-    class TodoItem extends Component<any, any> {
-      static template = xml`
-            <div class="todo">
-                <t t-esc="state.todo.title"/>
-                <button class="destroy" t-on-click="removeTodo">x</button>
-            </div>`;
-      state = useStore((state, props) => {
-        steps.push("item:usestore");
-        return {
-          todo: state.todos[props.id]
-        };
-      });
-
-      removeTodo() {
-        this.env.store.dispatch("removeTodo");
-      }
-      __render(f) {
-        steps.push("item:render");
-        return super.__render(f);
-      }
-    }
-
-    class TodoApp extends Component<any, any> {
-      static template = xml`
-            <div class="todoapp">
-                <t t-foreach="Object.values(state.todos)" t-as="todo">
-                    <TodoItem t-key="todo.id" id="todo.id"/>
-                </t>
-            </div>`;
-      static components = { TodoItem };
-      state = useStore(state => {
-        steps.push("app:usestore");
-        return { todos: state.todos };
-      });
-      __render(f) {
-        steps.push("app:render");
-        return super.__render(f);
-      }
-    }
-
-    (<any>env).store = store;
-    const app = new TodoApp();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe(
-      '<div class="todoapp"><div class="todo">kikoou<button class="destroy">x</button></div></div>'
-    );
-
-    expect(steps).toEqual(["app:usestore", "app:render", "item:usestore", "item:render"]);
-
-    fixture.querySelector("button")!.click();
-    await nextTick();
-    expect(steps).toEqual([
-      "app:usestore",
-      "app:render",
-      "item:usestore",
-      "item:render",
-      "app:usestore",
-      "app:render"
-    ]);
-    expect(fixture.innerHTML).toBe('<div class="todoapp"></div>');
-  });
-
-  test("connected component willpatch/patch hooks are called on store updates", async () => {
-    const steps: string[] = [];
-
-    class App extends Component<any, any> {
-      static template = xml`<div><t t-esc="store.msg"/></div>`;
-      store = useStore(s => ({ msg: s.msg }));
-
-      willPatch() {
-        steps.push("willpatch");
-      }
-      patched() {
-        steps.push("patched");
-      }
-    }
-
-    const state = { msg: "a" };
-    const actions = {
-      setMsg({ state }, c) {
-        state.msg = c;
-      }
-    };
-
-    const store = new Store({ state, actions });
-    (<any>env).store = store;
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div>a</div>");
-
-    store.dispatch("setMsg", "b");
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div>b</div>");
-    expect(steps).toEqual(["willpatch", "patched"]);
-  });
-
-  test("connected child components stop listening to store when destroyed", async () => {
-    let steps: any = [];
-
-    class Child extends Component<any, any> {
-      static template = xml`<div><t t-esc="store.val"/></div>`;
-      store = useStore(s => s);
-    }
-
-    class Parent extends Component<any, any> {
-      static template = xml`<div><Child t-if="state.child" /></div>`;
-      static components = { Child };
-      state = useState({ child: true });
-    }
-
-    class TestStore extends Store {
-      on(eventType, owner, callback) {
-        steps.push(`on:${eventType}`);
-        super.on(eventType, owner, callback);
-      }
-      off(eventType, owner) {
-        steps.push(`off:${eventType}`);
-        super.off(eventType, owner);
-      }
-    }
-    const store = new TestStore({ state: { val: 1 } });
-    (<any>env).store = store;
-    const parent = new Parent();
-
-    await parent.mount(fixture);
-    expect(steps).toEqual(["on:update"]);
-    expect(fixture.innerHTML).toBe("<div><div>1</div></div>");
-
-    parent.state.child = false;
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div></div>");
-    expect(steps).toEqual(["on:update", "off:update"]);
-  });
-
-  test("dispatch an action", async () => {
-    class App extends Component<any, any> {
-      static template = xml`<div><t t-esc="store.counter"/></div>`;
-      store = useStore(state => state);
-      dispatch = useDispatch();
-    }
-
-    const state = {
-      counter: 0
-    };
-
-    const actions = {
-      inc({ state }) {
-        return ++state.counter;
-      }
-    };
-
-    const store = new Store({ state, actions });
-    (<any>env).store = store;
-    const app = new App();
-
-    await app.mount(fixture);
-    expect(fixture.innerHTML).toBe("<div>0</div>");
-
-    const res = app.dispatch("inc");
-    expect(res).toBe(1);
-    await nextTick();
-    expect(fixture.innerHTML).toBe("<div>1</div>");
-  });
-});
-
-describe("various scenarios", () => {
-  let fixture: HTMLElement;
-  let env: Env;
-
-  beforeEach(() => {
-    fixture = makeTestFixture();
-    env = makeTestEnv();
-    config.env = env;
-  });
-
-  afterEach(() => {
-    fixture.remove();
-  });
-
-  test("scenarios with async store updates and some components events", async () => {
-    const actions = {
-      async deleteAttachment({ state }) {
-        await Promise.resolve();
-        delete state.attachments[100];
-        state.messages[10].attachmentIds = [];
-      }
-    };
-    const state = {
-      attachments: {
-        100: {
-          id: 100,
-          name: "text.txt"
-        }
-      },
-      messages: {
-        10: {
-          attachmentIds: [100],
-          id: 10
-        }
-      }
-    };
-    const store = new Store({ actions, state });
-
-    class Attachment extends Component<any, any> {
-      static template = xml`
-            <div>
-                <span>Attachment <t t-esc="props.id"/></span>
-                <span>Name: <t t-esc="attachment.name"/></span>
-            </div>`;
-
-      attachment = useStore((state, props) => ({ name: state.attachments[props.id].name }));
-    }
-
-    class Message extends Component<any, any> {
-      static template = xml`
-            <div>
-                <button t-on-click="doStuff">Do stuff</button>
-                <Attachment t-foreach="store.attachmentIds" t-key="attachmentId" t-as="attachmentId" id="attachmentId"/>
-            </div>`;
-
-      store = useStore(state => ({ attachmentIds: state.messages[10].attachmentIds }));
-      static components = { Attachment };
-      state = { isAttachmentDeleted: false };
-      dispatch = useDispatch();
-      doStuff() {
-        this.dispatch("deleteAttachment", 100);
-        this.state.isAttachmentDeleted = true;
-      }
-    }
-
-    (<any>env).store = store;
-    const message = new Message();
-
-    await message.mount(fixture);
-
-    expect(fixture.innerHTML).toMatchSnapshot();
-
-    fixture.querySelector("button")!.click();
-    await nextTick();
-    expect(fixture.innerHTML).toMatchSnapshot();
-  });
-});
@@ -1,5 +1,4 @@
 import { h, patch } from "../src/vdom";
-import { htmlToVDOM } from "../src/vdom/html_to_vdom";
 import { init, addNS } from "../src/vdom/vdom";

 function map(list, fn) {
@@ -185,6 +184,20 @@ describe("snabbdom", function() {
      expect(elm.tagName).toBe("DIV");
    });

+    test("has different tag and id", function() {
+      let elm: any = document.createElement("div");
+      vnode0.appendChild(elm);
+      const vnode1 = h("span#id");
+      elm = patch(elm, vnode1).elm;
+      expect(elm.tagName).toBe("SPAN");
+      expect(elm.id).toBe("id");
+    });
+
+    test("has id", function() {
+      elm = patch(vnode0, h("div", [h("div#unique")])).elm;
+      expect(elm.firstChild.id).toBe("unique");
+    });
+
    test("has correct namespace", function() {
      const SVGNamespace = "http://www.w3.org/2000/svg";
      const XHTMLNamespace = "http://www.w3.org/1999/xhtml";
@@ -204,6 +217,20 @@ describe("snabbdom", function() {
      expect(elm.firstChild.firstChild.namespaceURI).toBe(XHTMLNamespace);
    });

+    test("receives classes in selector", function() {
+      elm = patch(vnode0, h("div", [h("i.am.a.class")])).elm;
+      expect(elm.firstChild.classList.contains("am")).toBeTruthy();
+      expect(elm.firstChild.classList.contains("a")).toBeTruthy();
+      expect(elm.firstChild.classList.contains("class")).toBeTruthy();
+    });
+
+    test("receives classes in selector when namespaced", function() {
+      elm = patch(vnode0, h("svg", [h("g.am.a.class.too")])).elm;
+      expect(elm.firstChild.classList.contains("am")).toBeTruthy();
+      expect(elm.firstChild.classList.contains("a")).toBeTruthy();
+      expect(elm.firstChild.classList.contains("class")).toBeTruthy();
+    });
+
    test("can create elements with text content", function() {
      elm = patch(vnode0, h("div", ["I am a string"])).elm;
      expect(elm.innerHTML).toBe("I am a string");
@@ -240,6 +267,26 @@ describe("snabbdom", function() {
  });

  describe("patching an element", function() {
+    test("changes the elements classes", function() {
+      const vnode1 = h("i.i.am.horse");
+      const vnode2 = h("i.i.am");
+      patch(vnode0, vnode1);
+      elm = patch(vnode1, vnode2).elm;
+      expect(elm.classList.contains("i")).toBeTruthy();
+      expect(elm.classList.contains("am")).toBeTruthy();
+      expect(!elm.classList.contains("horse")).toBeTruthy();
+    });
+
+    test("removes missing classes", function() {
+      const vnode1 = h("i.i.am.horse");
+      const vnode2 = h("i.i.am");
+      patch(vnode0, vnode1);
+      elm = patch(vnode1, vnode2).elm;
+      expect(elm.classList.contains("i")).toBeTruthy();
+      expect(elm.classList.contains("am")).toBeTruthy();
+      expect(!elm.classList.contains("horse")).toBeTruthy();
+    });
+
    test("changes an elements props", function() {
      const vnode1 = h("a", { props: { src: "http://other/" } });
      const vnode2 = h("a", { props: { src: "http://localhost/" } });
@@ -1057,52 +1104,3 @@ describe("snabbdom", function() {
    });
  });
 });
-
-//------------------------------------------------------------------------------
-// Html to vdom
-//------------------------------------------------------------------------------
-describe("html to vdom", function() {
-  let elm, vnode0;
-  beforeEach(function() {
-    elm = document.createElement("div");
-    vnode0 = elm;
-  });
-
-  test("empty strings return empty list", function() {
-    expect(htmlToVDOM("")).toEqual([]);
-  });
-
-  test("just text", function() {
-    const nodeList = htmlToVDOM("simple text");
-    expect(nodeList).toHaveLength(1);
-    expect(nodeList[0]).toEqual({ text: "simple text" });
-  });
-
-  test("empty tag", function() {
-    const nodeList = htmlToVDOM("<span></span>");
-    expect(nodeList).toHaveLength(1);
-    elm = patch(vnode0, nodeList[0]).elm;
-    expect(elm.outerHTML).toEqual("<span></span>");
-  });
-
-  test("tag with text", function() {
-    const nodeList = htmlToVDOM("<span>abc</span>");
-    expect(nodeList).toHaveLength(1);
-    elm = patch(vnode0, nodeList[0]).elm;
-    expect(elm.outerHTML).toEqual("<span>abc</span>");
-  });
-
-  test("tag with attribute", function() {
-    const nodeList = htmlToVDOM(`<span a="1" b="2">abc</span>`);
-    expect(nodeList).toHaveLength(1);
-    elm = patch(vnode0, nodeList[0]).elm;
-    expect(elm.outerHTML).toEqual(`<span a="1" b="2">abc</span>`);
-  });
-
-  test("misc", function() {
-    const nodeList = htmlToVDOM(`<span a="1" b="2">abc<div>1</div></span>`);
-    expect(nodeList).toHaveLength(1);
-    elm = patch(vnode0, nodeList[0]).elm;
-    expect(elm.outerHTML).toEqual(`<span a="1" b="2">abc<div>1</div></span>`);
-  });
-});
@@ -1,155 +0,0 @@
-import { buildData, startMeasure, stopMeasure, formatNumber } from "../shared/utils.js";
-
-const { useState, useRef } = owl.hooks;
-//------------------------------------------------------------------------------
-// Likes Counter Widget
-//------------------------------------------------------------------------------
-class Counter extends owl.Component {
-  state = useState({ counter: 0 });
-
-  increment() {
-    this.state.counter++;
-  }
-}
-
-//------------------------------------------------------------------------------
-// Message Widget
-//------------------------------------------------------------------------------
-class Message extends owl.Component {
-  static components = { Counter };
-
-  shouldUpdate(nextProps) {
-    return nextProps.message !== this.props.message;
-  }
-  removeMessage() {
-    this.trigger("remove-message", {
-      id: this.props.message.id
-    });
-  }
-}
-
-//------------------------------------------------------------------------------
-// Root Widget
-//------------------------------------------------------------------------------
-class App extends owl.Component {
-  static components = { Message };
-  state = useState({ messages: [], multipleFlag: false, clearAfterFlag: false });
-  logRef = useRef("log");
-
-  mounted() {
-    this.log(`Benchmarking Owl v${owl.__info__.version} (build date: ${owl.__info__.date})`);
-  }
-
-  benchmark(message, fn, callback) {
-    if (this.state.multipleFlag) {
-      const N = 20;
-      let n = N;
-      let total = 0;
-      let cb = info => {
-        let finalize = () => {
-          n--;
-          total += info.delta;
-          if (n === 0) {
-            const avg = total / N;
-            this.log(`Average: ${formatNumber(avg)}ms`, true);
-            if (callback) {
-              callback();
-            }
-          } else {
-            this._benchmark(message, fn, cb);
-          }
-        };
-
-        if (this.state.clearAfterFlag) {
-          this._benchmark(
-            "clear",
-            () => {
-              this.state.messages = [];
-            },
-            finalize,
-            false
-          );
-        } else {
-          finalize();
-        }
-      };
-      this._benchmark(message, fn, cb);
-    } else {
-      this._benchmark(message, fn, callback);
-    }
-  }
-
-  _benchmark(message, fn, cb, log = true) {
-    setTimeout(() => {
-      startMeasure(message);
-      fn();
-      stopMeasure(info => {
-        if (log) {
-          this.log(info.msg);
-        }
-        if (cb) {
-          cb(info);
-        }
-      });
-    }, 10);
-  }
-
-  addMessages(n) {
-    this.benchmark("add " + n, () => {
-      const newMessages = buildData(n);
-      this.state.messages.push.apply(this.state.messages, newMessages);
-    });
-  }
-
-  clear() {
-    this._benchmark("clear", () => {
-      this.state.messages = [];
-    });
-  }
-
-  updateSomeMessages() {
-    this.benchmark("update every 10th", () => {
-      const messages = this.state.messages;
-      for (let i = 0; i < messages.length; i += 10) {
-        const msg = Object.assign({}, messages[i]);
-        msg.author += "!!!";
-        messages[i] = msg;
-      }
-    });
-  }
-
-  removeMessage(event) {
-    this.benchmark("remove message", () => {
-      const index = this.state.messages.findIndex(m => m.id === event.detail.id);
-      this.state.messages.splice(index, 1);
-    });
-  }
-
-  log(str, isBold) {
-    const div = document.createElement("div");
-    if (isBold) {
-      div.classList.add("bold");
-    }
-    div.textContent = `> ${str}`;
-    this.logRef.el.appendChild(div);
-    this.logRef.el.scrollTop = this.logRef.el.scrollHeight;
-  }
-
-  clearLog() {
-    this.logRef.el.innerHTML = "";
-  }
-}
-
-//------------------------------------------------------------------------------
-// Application initialization
-//------------------------------------------------------------------------------
-async function start() {
-  const templates = await owl.utils.loadFile("templates.xml");
-  const env = {
-    qweb: new owl.QWeb(templates)
-  };
-  const app = new App(env);
-  app.mount(document.body);
-}
-
-start();
@@ -1,12 +0,0 @@
-<!DOCTYPE html>
-<html lang="en">
-<head>
-  <meta charset="UTF-8">
-  <title>OWL v0.24.0 Benchmark</title>
-  <link href="../shared/main.css" rel="stylesheet"/>
-  <script src='../../owl.js'></script>
-</head>
-<body>
-  <script src='app.js' type="module"></script>
-</body>
-</html>
@@ -1,50 +0,0 @@
-<templates>
-  <div t-name="App" class="main">
-      <div class="left-thing">
-        <div class="title">Actions</div>
-        <div class="panel">
-          <button t-on-click="addMessages(100)">Add 100 messages</button>
-          <button t-on-click="addMessages(1000)">Add 1k messages</button>
-          <button t-on-click="addMessages(10000)">Add 10k messages</button>
-          <button t-on-click="addMessages(30000)">Add 30k messages</button>
-          <button t-on-click="updateSomeMessages">Update every 10th messages</button>
-          <button t-on-click="clear">Clear</button>
-        </div>
-        <div class="flags">
-            <div>
-                <input type="checkbox" id="multipleflag" t-model="state.multipleFlag"/>
-                <label for="multipleflag">Do it 20x</label>
-            </div>
-            <div>
-                <input type="checkbox" id="clearFlag" t-model="state.clearAfterFlag" />
-                <label for="clearFlag">Clear after</label>
-            </div>
-        </div>
-        <div class="info">Number of messages: <t t-esc="state.messages.length"/></div>
-        <hr/>
-        <div class="title">Log <span class="clear-log" t-on-click="clearLog">(clear)</span></div>
-        <div class="log">
-            <div class="log-content" t-ref="log"/>
-        </div>
-      </div>
-      <div class="right-thing">
-          <div class="content" t-on-remove-message="removeMessage">
-              <t t-foreach="state.messages" t-as="message">
-                  <Message t-key="message.id" message="message"/>
-              </t>
-          </div>
-      </div>
-  </div>
-
-  <div t-name="Message" class="message">
-    <span class="author"><t t-esc="props.message.author"/></span>
-    <span class="msg"><t t-esc="props.message.msg"/></span>
-    <button class="remove" t-on-click="removeMessage">Remove</button>
-    <Counter/>
-  </div>
-
-  <div t-name="Counter">
-    <button t-on-click="increment">Value: <t t-esc="state.counter"/></button>
-  </div>
-
-</templates>
@@ -144,11 +144,11 @@ class App extends owl.Component {
 // Application initialization
 //------------------------------------------------------------------------------
 async function start() {
-  const templates = await owl.utils.loadFile("templates.xml");
-  owl.config.env = {
-    qweb: new owl.QWeb({ templates })
+  const templates = await owl.utils.loadTemplates("templates.xml");
+  const env = {
+    qweb: new owl.QWeb(templates)
  };
-  const app = new App();
+  const app = new App(env);
  app.mount(document.body);
 }

@@ -44,17 +44,15 @@ export function startMeasure(descr) {
 export function stopMeasure(cb) {
  let last = lastMeasure;
  if (lastMeasure) {
-      window.requestAnimationFrame(() => {
-        window.setTimeout(function() {
-        lastMeasure = null;
-        const stop = performance.now();
-        const delta = stop - startTime;
-        const msg = `[${last}] took  ${formatNumber(delta)}ms`;
-        console.log(msg);
-        if (cb) {
-            cb({ msg, delta });
-        }
-        }, 0);
-      });
+    window.setTimeout(function() {
+      lastMeasure = null;
+      const stop = performance.now();
+      const delta = stop - startTime;
+      const msg = `[${last}] took  ${formatNumber(delta)}ms`;
+      console.log(msg);
+      if (cb) {
+        cb({ msg, delta });
+      }
+    }, 0);
  }
 }
@@ -40,7 +40,6 @@
                <li><a href="benchmarks/owl-0.17.0">OWL 0.17.0</a></li>
                <li><a href="benchmarks/owl-0.18.0">OWL 0.18.0</a></li>
                <li><a href="benchmarks/owl-0.21.0">OWL 0.21.0</a></li>
-                <li><a href="benchmarks/owl-0.24.0">OWL 0.24.0</a></li>
                <li><a href="benchmarks/owl-master">OWL Master</a></li>
            </ul>
            <ul>
@@ -1,5 +1,5 @@
 import { SAMPLES } from "./samples.js";
-const { useState, useRef, onMounted, onWillUnmount } = owl.hooks;
+const {useState, useRef} = owl.hooks;
 //------------------------------------------------------------------------------
 // Constants, helpers, utils
 //------------------------------------------------------------------------------
@@ -90,14 +90,7 @@ function makeCodeIframe(js, css, xml, errorHandler) {
    owlScript.addEventListener("load", () => {
      const script = doc.createElement("script");
      script.type = "text/javascript";
-      const content = `
-        {
-          owl.__info__.mode = 'dev';
-          let templates = \`${sanitizedXML}\`;
-          const qweb = new owl.QWeb({ templates });
-          owl.config.env = { qweb };
-        }
-        ${js}`;
+      const content = `owl.__info__.mode = 'dev';\nwindow.TEMPLATES = \`${sanitizedXML}\`\n${js}`;
      script.innerHTML = content;
      iframe.contentWindow.addEventListener("error", errorHandler);
      iframe.contentWindow.addEventListener("unhandledrejection", errorHandler);
@@ -134,7 +127,7 @@ async function makeApp(js, css, xml) {
  const JS = `
 async function loadTemplates() {
  try {
-    return owl.utils.loadFile('app.xml');
+    return owl.utils.loadTemplates('app.xml');
  } catch(e) {
    console.error(\`This app requires a static server.  If you have python installed, try 'python app.py'\`);
  }
@@ -157,51 +150,6 @@ Promise.all([loadTemplates(), owl.utils.whenReady()]).then(start);
  return zip.generateAsync({ type: "blob" });
 }

-//------------------------------------------------------------------------------
-// SAMPLES
-//------------------------------------------------------------------------------
-function loadSamples() {
-  let result = SAMPLES.slice();
-  const localSample = localStorage.getItem("owl-playground-local-sample");
-  if (localSample) {
-    const { js, css, xml } = JSON.parse(localSample);
-    result.unshift({
-      description: "Local Storage Code",
-      code: js,
-      xml,
-      css
-    });
-  }
-  return result;
-}
-
-function saveLocalSample(js, css, xml) {
-  const str = JSON.stringify({ js, css, xml });
-  localStorage.setItem("owl-playground-local-sample", str);
-}
-
-function deleteLocalSample() {
-  localStorage.removeItem("owl-playground-local-sample");
-}
-
-function useSamples() {
-  const samples = loadSamples();
-  const component = owl.Component.current;
-  let interval;
-
-  onMounted(() => {
-    const state = component.state;
-    interval = setInterval(() => {
-      if (component.isDirty) {
-        saveLocalSample(state.js, state.css, state.xml);
-      }
-    }, 1000);
-  });
-  onWillUnmount(() => {
-    clearInterval(interval);
-  });
-  return samples;
-}
 //------------------------------------------------------------------------------
 // Tabbed editor
 //------------------------------------------------------------------------------
@@ -209,14 +157,13 @@ class TabbedEditor extends owl.Component {
  constructor(parent, props) {
    super(parent, props);
    this.state = useState({
-      currentTab: props.js !== false ? "js" : props.xml ? "xml" : "css"
+      currentTab: props.js ? "js" : props.xml ? "xml" : "css"
    });
    this.setTab = owl.utils.debounce(this.setTab, 250, true);

    this.sessions = {};
    this._setupSessions(props);
    this.editorNode = useRef("editor");
-    this._updateCode = this._updateCode.bind(this);
  }

  mounted() {
@@ -228,14 +175,18 @@ class TabbedEditor extends owl.Component {
    this.editor.setSession(this.sessions[this.state.currentTab]);
    const tabSize = this.state.currentTab === "xml" ? 2 : 4;
    this.editor.session.setOption("tabSize", tabSize);
-    this.editor.on("blur", this._updateCode);
-    this.interval = setInterval(this._updateCode, 3000);
+    this.editor.on("blur", () => {
+      const editorValue = this.editor.getValue();
+      const propsValue = this.props[this.state.currentTab];
+      if (editorValue !== propsValue) {
+        this.trigger("updateCode", {
+          type: this.state.currentTab,
+          value: editorValue
+        });
+      }
+    });
  }

-  willUnmount() {
-    clearInterval(this.interval);
-    this.editor.off("blur", this._updateCode);
-  }
  willUpdateProps(nextProps) {
    this._setupSessions(nextProps);
  }
@@ -244,15 +195,13 @@ class TabbedEditor extends owl.Component {
    const session = this.sessions[this.state.currentTab];
    let content = this.props[this.state.currentTab];
    if (content === false) {
-      const tab = this.props.js !== false ? "js" : this.props.xml ? "xml" : "css";
+      const tab = this.props.js ? "js" : this.props.xml ? "xml" : "css";
      content = this.props[tab];
      this.state.currentTab = tab;
    }
-    if (this.editor.getValue() !== content) {
-      session.setValue(content, -1);
-      this.editor.setSession(session);
-      this.editor.resize();
-    }
+    session.setValue(content, -1);
+    this.editor.setSession(session);
+    this.editor.resize();
  }

  setTab(tab) {
@@ -281,7 +230,7 @@ class TabbedEditor extends owl.Component {

  _setupSessions(props) {
    for (let tab of ["js", "xml", "css"]) {
-      if (props[tab] !== false && !this.sessions[tab]) {
+      if (props[tab] && !this.sessions[tab]) {
        this.sessions[tab] = new ace.EditSession(props[tab], MODES[tab]);
        this.sessions[tab].setOption("useWorker", false);
        const tabSize = tab === "xml" ? 2 : 4;
@@ -290,17 +239,6 @@ class TabbedEditor extends owl.Component {
      }
    }
  }
-
-  _updateCode() {
-    const editorValue = this.editor.getValue();
-    const propsValue = this.props[this.state.currentTab];
-    if (editorValue !== propsValue) {
-      this.trigger("updateCode", {
-        type: this.state.currentTab,
-        value: editorValue
-      });
-    }
-  }
 }

 //------------------------------------------------------------------------------
@@ -310,13 +248,12 @@ class App extends owl.Component {
  constructor(...args) {
    super(...args);
    this.version = owl.__info__.version;
-    this.SAMPLES = useSamples();
-    this.isDirty = false;
+    this.SAMPLES = SAMPLES;

    this.state = useState({
-      js: this.SAMPLES[0].code,
-      css: this.SAMPLES[0].css || "",
-      xml: this.SAMPLES[0].xml || DEFAULT_XML,
+      js: SAMPLES[0].code,
+      css: SAMPLES[0].css || "",
+      xml: SAMPLES[0].xml || DEFAULT_XML,
      error: false,
      displayWelcome: true,
      splitLayout: true,
@@ -365,12 +302,10 @@ class App extends owl.Component {
  }

  setSample(ev) {
-    const sample = this.SAMPLES.find(s => s.description === ev.target.value);
+    const sample = SAMPLES.find(s => s.description === ev.target.value);
    this.state.js = sample.code;
    this.state.css = sample.css || "";
    this.state.xml = sample.xml || DEFAULT_XML;
-    deleteLocalSample();
-    this.isDirty = false;
  }

  get leftPaneStyle() {
@@ -403,10 +338,7 @@ class App extends owl.Component {
    });
  }
  updateCode(ev) {
-    if (this.state[ev.detail.type] !== ev.detail.value) {
-      this.state[ev.detail.type] = ev.detail.value;
-      this.isDirty = true;
-    }
+    this.state[ev.detail.type] = ev.detail.value;
  }
  toggleLayout() {
    this.state.splitLayout = !this.state.splitLayout;
@@ -431,20 +363,18 @@ class App extends owl.Component {
 }
 App.components = { TabbedEditor };

+
 //------------------------------------------------------------------------------
 // Application initialization
 //------------------------------------------------------------------------------
 async function start() {
  document.title = `${document.title} (v${owl.__info__.version})`;
-  const commit = `https://github.com/odoo/owl/commit/${owl.__info__.hash}`;
-  console.info(`This application is using Owl built with the following commit:`, commit);
  const [templates] = await Promise.all([
-    owl.utils.loadFile("templates.xml"),
+    owl.utils.loadTemplates("templates.xml"),
    owl.utils.whenReady()
  ]);
-  const qweb = new owl.QWeb({ templates });
-  owl.config.env = { qweb };
-  const app = new App();
+  const qweb = new owl.QWeb(templates);
+  const app = new App({ qweb });
  app.mount(document.body);
 }

@@ -11,12 +11,14 @@ class Greeter extends Component {

 // Main root component
 class App extends Component {
+    static components = { Greeter };
    state = useState({ name: 'World'});
 }
-App.components = { Greeter };

 // Application setup
-const app = new App();
+// Note that the xml templates are injected into the global TEMPLATES variable.
+const qweb = new owl.QWeb(TEMPLATES);
+const app = new App({ qweb });
 app.mount(document.body);
 `;

@@ -56,6 +58,7 @@ class Counter extends Component {

 class App extends Component {
    state = useState({ flag: false, componentFlag: false, numbers: [] });
+    static components = { Counter };

    toggle(key) {
        this.state[key] = !this.state[key];
@@ -65,10 +68,11 @@ class App extends Component {
        const n = this.state.numbers.length + 1;
        this.state.numbers.push(n);
    }
-}
-App.components = { Counter };

-const app = new App();
+}
+
+const qweb = new owl.QWeb(TEMPLATES);
+const app = new App({qweb});
 app.mount(document.body);
 `;

@@ -213,6 +217,7 @@ class DemoComponent extends Component {
 }

 class App extends Component {
+    static components = { DemoComponent };
    state = useState({ n: 0, flag: true });

    increment() {
@@ -223,9 +228,9 @@ class App extends Component {
        this.state.flag = !this.state.flag;
    }
 }
-App.components = { DemoComponent };

-const app = new App();
+const qweb = new owl.QWeb(TEMPLATES);
+const app = new App({ qweb });
 app.mount(document.body);
 `;

@@ -294,7 +299,8 @@ class App extends owl.Component {
 }

 // Application setup
-const app = new App();
+const qweb = new owl.QWeb(TEMPLATES);
+const app = new App({ qweb });
 app.mount(document.body);
 `;

@@ -312,62 +318,6 @@ const HOOKS_CSS = `button {
    font-size: 16px;
 }`;

-const CONTEXT_JS = `// In this example, we show how components can use the Context and 'useContext'
-// hook to share information between them.
-const { Component, Context } = owl;
-const { useContext } = owl.hooks;
-
-class ToolbarButton extends Component {
-    theme = useContext(this.env.themeContext);
-
-    get style () {
-        const theme = this.theme;
-        return \`background-color: \${theme.background}; color: \${theme.foreground}\`;
-    }
-}
-
-class Toolbar extends Component {}
-Toolbar.components = { ToolbarButton };
-
-// Main root component
-class App extends Component {
-    toggleTheme() {
-        const { background, foreground } = this.env.themeContext.state;
-        this.env.themeContext.state.background = foreground;
-        this.env.themeContext.state.foreground = background;
-    }
-}
-App.components = { Toolbar };
-
-// Application setup
-const themeContext = new Context({
-   background: '#000',
-   foreground: '#fff',
-});
-// Add the themeContext the environment to make it available to all components
-owl.config.env.themeContext = themeContext;
-const app = new App();
-app.mount(document.body);
-`;
-
-const CONTEXT_XML = `<templates>
-  <button t-name="ToolbarButton" t-att-style="style">
-    <t t-esc="props.name"/>
-  </button>
-
-  <div t-name="Toolbar">
-    <ToolbarButton name="'A'"/>
-    <ToolbarButton name="'B'"/>
-    <ToolbarButton name="'C'"/>
-  </div>
-
-  <div t-name="App">
-    <button t-on-click="toggleTheme">Toggle Mode</button>
-    <Toolbar/>
-  </div>
-</templates>
-`;
-
 const TODO_APP_STORE = `// This example is an implementation of the TodoList application, from the
 // www.todomvc.com project.  This is a non trivial application with some
 // interesting user interactions. It uses the local storage for persistence.
@@ -375,88 +325,97 @@ const TODO_APP_STORE = `// This example is an implementation of the TodoList app
 // In this implementation, we use the owl Store class to manage the state.  It
 // is very similar to the VueX store.
 const { Component, useState } = owl;
-const { useRef, useStore, useDispatch, onPatched, onMounted } = owl.hooks;
+const { useRef } = owl.hooks;

-//------------------------------------------------------------------------------
-// Constants, helpers
-//------------------------------------------------------------------------------
 const ENTER_KEY = 13;
 const ESC_KEY = 27;
 const LOCALSTORAGE_KEY = "todomvc";

-function useAutofocus(name) {
-  let ref = useRef(name);
-  let isInDom = false;
-  function updateFocus() {
-    if (!isInDom && ref.el) {
-      isInDom = true;
-      const current = ref.el.value;
-      ref.el.value = "";
-      ref.el.focus();
-      ref.el.value = current;
-    } else if (isInDom && !ref.el) {
-      isInDom = false;
-    }
-  }
-  onPatched(updateFocus);
-  onMounted(updateFocus);
-}
-
 //------------------------------------------------------------------------------
-// Store
+// Store Definition
 //------------------------------------------------------------------------------
-const initialState = { todos: [], nextId: 1};
-
 const actions = {
    addTodo({ state }, title) {
-        const todo = {
+        state.todos.push({
            id: state.nextId++,
            title,
            completed: false
-        }
-        state.todos.push(todo);
+        });
    },
    removeTodo({ state }, id) {
        const index = state.todos.findIndex(t => t.id === id);
        state.todos.splice(index, 1);
    },
-    updateTodo({state, dispatch}, {id, title}) {
-        const value = title.trim();
-        if (!value) {
-            dispatch('removeTodo', id);
-        } else {
-            const todo = state.todos.find(t => t.id === id);
-            todo.title = value;
-        }
-    },
-    toggleTodo({ state }, id) {
+    toggleTodo({ state, dispatch }, id) {
        const todo = state.todos.find(t => t.id === id);
-        todo.completed = !todo.completed;
+        dispatch("editTodo", { id, completed: !todo.completed });
    },
    clearCompleted({ state, dispatch }) {
-        for (let todo of state.todos) {
-            if (todo.completed) {
+        state.todos
+            .filter(todo => todo.completed)
+            .forEach(todo => {
                dispatch("removeTodo", todo.id);
-            }
-        }
+            });
    },
    toggleAll({ state, dispatch }, completed) {
-        for (let todo of state.todos) {
+        state.todos.forEach(todo => {
+            dispatch("editTodo", {
+                id: todo.id,
+                completed
+            });
+        });
+    },
+    editTodo({ state }, { id, title, completed }) {
+        const todo = state.todos.find(t => t.id === id);
+        if (title !== undefined) {
+            todo.title = title;
+        }
+        if (completed !== undefined) {
            todo.completed = completed;
        }
-    },
+    }
 };

+function saveState(state) {
+    const str = JSON.stringify(state);
+    window.localStorage.setItem(LOCALSTORAGE_KEY, str);
+}
+
+function loadState() {
+    const localState = window.localStorage.getItem(LOCALSTORAGE_KEY);
+    return localState ? JSON.parse(localState) : { todos: [], nextId: 1};
+}
+
+function makeStore() {
+    const state = loadState();
+    const store = new owl.store.Store({ state, actions });
+    store.on("update", null, () => saveState(store.state));
+    return store;
+}
+
 //------------------------------------------------------------------------------
 // TodoItem
 //------------------------------------------------------------------------------
 class TodoItem extends Component {
    state = useState({ isEditing: false });
-    dispatch = useDispatch();
+    inputRef = useRef("input");

-    constructor(...args) {
-        super(...args);
-        useAutofocus("input");
+    removeTodo() {
+        this.env.store.dispatch("removeTodo", this.props.id);
+    }
+
+    toggleTodo() {
+        this.env.store.dispatch("toggleTodo", this.props.id);
+    }
+
+    async editTodo() {
+        this.state.isEditing = true;
+    }
+
+    focusInput() {
+        this.inputRef.el.value = "";
+        this.inputRef.el.focus();
+        this.inputRef.el.value = this.props.title;
    }

    handleKeyup(ev) {
@@ -474,33 +433,48 @@ class TodoItem extends Component {
    }

    updateTitle(title) {
-        this.dispatch("updateTodo", {title, id: this.props.id});
-        this.state.isEditing = false;
+        const value = title.trim();
+        if (!value) {
+            this.removeTodo(this.props.id);
+        } else {
+            this.env.store.dispatch("editTodo", {
+                id: this.props.id,
+                title: value
+            });
+            this.state.isEditing = false;
+        }
    }
 }

 //------------------------------------------------------------------------------
 // TodoApp
 //------------------------------------------------------------------------------
-class TodoApp extends Component {
+class TodoApp extends owl.store.ConnectedComponent {
+    static components = { TodoItem };
    state = useState({ filter: "all" });
-    todos = useStore(state => state.todos);
-    dispatch = useDispatch();

+    static mapStoreToProps(state) {
+        return {
+            todos: state.todos
+        };
+    }
    get visibleTodos() {
-        switch (this.state.filter) {
-            case "active": return this.todos.filter(t => !t.completed);
-            case "completed": return this.todos.filter(t => t.completed);
-            case "all": return this.todos;
+        let todos = this.storeProps.todos;
+        if (this.state.filter === "active") {
+            todos = todos.filter(t => !t.completed);
        }
+        if (this.state.filter === "completed") {
+            todos = todos.filter(t => t.completed);
+        }
+        return todos;
    }

    get allChecked() {
-        return this.todos.every(todo => todo.completed);
+        return this.storeProps.todos.every(todo => todo.completed);
    }

    get remaining() {
-        return this.todos.filter(todo => !todo.completed).length;
+        return this.storeProps.todos.filter(todo => !todo.completed).length;
    }

    get remainingText() {
@@ -522,30 +496,17 @@ class TodoApp extends Component {
        this.state.filter = filter;
    }
 }
-TodoApp.components = { TodoItem };

 //------------------------------------------------------------------------------
 // App Initialization
 //------------------------------------------------------------------------------
-
-function makeStore() {
-    function saveState(state) {
-        const str = JSON.stringify(state);
-        window.localStorage.setItem(LOCALSTORAGE_KEY, str);
-    }
-    function loadState() {
-        const localState = window.localStorage.getItem(LOCALSTORAGE_KEY);
-        return localState ? JSON.parse(localState) : initialState;
-    }
-
-    const state = loadState();
-    const store = new owl.Store({ state, actions });
-    store.on("update", null, () => saveState(store.state));
-    return store;
-}
-
-owl.config.env.store = makeStore();
-const app = new TodoApp();
+const store = makeStore();
+const qweb = new owl.QWeb(TEMPLATES);
+const env = {
+    qweb,
+    store,
+};
+const app = new TodoApp(env);
 app.mount(document.body);
 `;

@@ -555,7 +516,7 @@ const TODO_APP_STORE_XML = `<templates>
      <h1>todos</h1>
      <input class="new-todo" autofocus="true" autocomplete="off" placeholder="What needs to be done?" t-on-keyup="addTodo"/>
    </header>
-    <section class="main" t-if="todos.length">
+    <section class="main" t-if="storeProps.todos.length">
      <input class="toggle-all" id="toggle-all" type="checkbox" t-att-checked="allChecked" t-on-click="dispatch('toggleAll', !allChecked)"/>
      <label for="toggle-all"></label>
      <ul class="todo-list">
@@ -564,7 +525,7 @@ const TODO_APP_STORE_XML = `<templates>
        </t>
      </ul>
    </section>
-    <footer class="footer" t-if="todos.length">
+    <footer class="footer" t-if="storeProps.todos.length">
      <span class="todo-count">
        <strong>
            <t t-esc="remaining"/>
@@ -582,7 +543,7 @@ const TODO_APP_STORE_XML = `<templates>
          <a t-on-click="setFilter('completed')" t-att-class="{selected: state.filter === 'completed'}">Completed</a>
        </li>
      </ul>
-      <button class="clear-completed" t-if="todos.length gt remaining" t-on-click="dispatch('clearCompleted')">
+      <button class="clear-completed" t-if="storeProps.todos.length gt remaining" t-on-click="dispatch('clearCompleted')">
        Clear completed
      </button>
    </footer>
@@ -590,13 +551,13 @@ const TODO_APP_STORE_XML = `<templates>

  <li t-name="TodoItem" class="todo" t-att-class="{completed: props.completed, editing: state.isEditing}">
    <div class="view">
-      <input class="toggle" type="checkbox" t-on-change="dispatch('toggleTodo', props.id)" t-att-checked="props.completed"/>
-      <label t-on-dblclick="state.isEditing = true">
+      <input class="toggle" type="checkbox" t-on-change="toggleTodo" t-att-checked="props.completed"/>
+      <label t-on-dblclick="editTodo">
        <t t-esc="props.title"/>
      </label>
-      <button class="destroy" t-on-click="dispatch('removeTodo', props.id)"></button>
+      <button class="destroy" t-on-click="removeTodo"></button>
    </div>
-    <input class="edit" t-ref="input" t-if="state.isEditing" t-att-value="props.title" t-on-keyup="handleKeyup" t-on-blur="handleBlur"/>
+    <input class="edit" t-ref="input" t-if="state.isEditing" t-att-value="props.title" t-on-keyup="handleKeyup" t-mounted="focusInput" t-on-blur="handleBlur"/>
  </li>
 </templates>`;

@@ -999,20 +960,23 @@ class Navbar extends owl.Component {}

 class MobileSearchView extends owl.Component {}

-class ControlPanel extends owl.Component {}
-ControlPanel.components = { MobileSearchView };
+class ControlPanel extends owl.Component {
+    static components = { MobileSearchView };
+}

 class AdvancedComponent extends owl.Component {}

-class FormView extends owl.Component {}
-FormView.components = { AdvancedComponent };
+class FormView extends owl.Component {
+    static components = { AdvancedComponent };
+}

 class Chatter extends owl.Component {
    messages = Array.from(Array(100).keys());
 }

-class App extends owl.Component {}
-App.components = { Navbar, ControlPanel, FormView, Chatter };
+class App extends owl.Component {
+    static components = { Navbar, ControlPanel, FormView, Chatter };
+}

 //------------------------------------------------------------------------------
 // Responsive plugin
@@ -1032,9 +996,12 @@ function setupResponsivePlugin(env) {
 //------------------------------------------------------------------------------
 // Application Startup
 //------------------------------------------------------------------------------
-setupResponsivePlugin(owl.config.env);
+const env = {
+    qweb: new owl.QWeb(TEMPLATES),
+};
+setupResponsivePlugin(env);

-const app = new App();
+const app = new App(env);
 app.mount(document.body);
 `;

@@ -1167,16 +1134,17 @@ class Counter extends Component {

 // Main root component
 class App extends Component {
+    static components = {Card, Counter};
    state = useState({a: 1, b: 3});

    inc(key, delta) {
        this.state[key] += delta;
    }
 }
-App.components = {Card, Counter};

 // Application setup
-const app = new App();
+const qweb = new owl.QWeb(TEMPLATES);
+const app = new App({ qweb });
 app.mount(document.body);`;

 const SLOTS_XML = `<templates>
@@ -1261,10 +1229,9 @@ const ASYNC_COMPONENTS = `// This example will not work if your browser does not

 // In this example, we have 2 sub components, one of them being async (slow).
 // However, we don't want renderings of the other sub component to be delayed
-// because of the slow component. We use the AsyncRoot component for this
+// because of the slow component. We use the 't-asyncroot' directive for this
 // purpose. Try removing it to see the difference.
 const { Component, useState } = owl;
-const { AsyncRoot } = owl.misc;

 class SlowComponent extends Component {
    willUpdateProps() {
@@ -1277,6 +1244,7 @@ class SlowComponent extends Component {
 class NotificationList extends Component {}

 class App extends Component {
+    static components = {SlowComponent, NotificationList};
    state = useState({ value: 0, notifs: [] });

    increment() {
@@ -1289,9 +1257,9 @@ class App extends Component {
        }, 3000);
    }
 }
-App.components = {SlowComponent, NotificationList, AsyncRoot};

-const app = new App();
+const qweb = new owl.QWeb(TEMPLATES);
+const app = new App({ qweb });
 app.mount(document.body);
 `;

@@ -1299,10 +1267,9 @@ const ASYNC_COMPONENTS_XML = `<templates>
  <div t-name="App" class="app">
    <button t-on-click="increment">Increment</button>
    <SlowComponent value="state.value"/>
-    <AsyncRoot>
-      <NotificationList notifications="state.notifs"/>
-    </AsyncRoot>
+    <NotificationList t-asyncroot="1" notifications="state.notifs"/>
  </div>
+
  <div t-name="SlowComponent" class="value" >
    Current value: <t t-esc="props.value"/>
  </div>
@@ -1360,7 +1327,8 @@ class Form extends Component {
 }

 // Application setup
-const form = new Form();
+const qweb = new owl.QWeb(TEMPLATES);
+const form = new Form({ qweb });
 form.mount(document.body);
 `;

@@ -1470,6 +1438,7 @@ class Window extends Component {
 }

 class WindowManager extends Component {
+  static components = { Window };
  windows = [];
  nextId = 1;
  currentZindex = 1;
@@ -1515,17 +1484,17 @@ class WindowManager extends Component {
    ev.target.style["z-index"] = w.zindex;
  }
 }
-WindowManager.components = { Window };

 class App extends Component {
+  static components = { WindowManager };
  wmRef = useRef("wm");

  addWindow(name) {
    this.wmRef.comp.addWindow(name);
  }
 }
-App.components = { WindowManager };

+const qweb = new owl.QWeb(TEMPLATES);
 const windows = [
  {
    name: "Hello",
@@ -1543,8 +1512,8 @@ const windows = [
  }
 ];

-owl.config.env.windows = windows;
-const app = new App();
+const env = { qweb, windows };
+const app = new App(env);
 app.mount(document.body);
 `;

@@ -1656,6 +1625,135 @@ const WMS_CSS = `body {
    font-size: 20px;
 }`;

+const MONKEYPATCH = `
+// In this example, we show a possible way components can be monkey patched.
+// This involves the functions patch/unpatch, which modifies the prototype of a
+// class (not only an owl component). Sadly, the patch code cannot make use of
+// the syntactic sugar that JS engines provides to classes, so it needs to use
+// the "this._super()" syntax instead of the standard "super.someMethod()".
+
+//--------------------------------------------------------------------------
+// Patching Code
+//--------------------------------------------------------------------------
+const patchMap = new WeakMap();
+
+function patch(C, patchName, patch) {
+    let metadata = patchMap.get(C.prototype);
+    if (!metadata) {
+        metadata = {
+          origMethods: {},
+          patches: {},
+          current: []
+        };
+        patchMap.set(C.prototype, metadata);
+    }
+  const proto = C.prototype;
+  if (metadata.patches[patchName]) {
+    throw new Error(\`Patch [\${patchName}] already exists\`);
+  }
+  metadata.patches[patchName] = patch;
+  applyPatch(proto, patch);
+  metadata.current.push(patchName);
+
+  function applyPatch(proto, patch) {
+    Object.keys(patch).forEach(function(methodName) {
+      const method = patch[methodName];
+      if (typeof method === "function") {
+        const original = proto[methodName];
+        if (!(methodName in metadata.origMethods)) {
+          metadata.origMethods[methodName] = original;
+        }
+        proto[methodName] = function(...args) {
+          this._super = original;
+          return method.call(this, ...args);
+        };
+      }
+    });
+  }
+}
+
+// we define here an unpatch function.  This is mostly useful if we want to
+// remove a patch.  For example, for testing purposes
+function unpatch(C, patchName) {
+  const proto = C.prototype;
+  let metadata = patchMap.get(proto);
+  if (!metdata) {
+    return;
+  }
+  patchMap.delete(proto);
+
+  // reset to original
+  for (let k in metadata.origMethods) {
+    proto[k] = metadata.origMethods[k];
+  }
+
+  // apply other patches
+  for (let name of metadata.current) {
+    if (name !== patchName) {
+      patch(C, name, metadata.patches[name]);
+    }
+  }
+}
+
+
+//--------------------------------------------------------------------------
+// Components
+//--------------------------------------------------------------------------
+const { Component, useState } = owl;
+
+class Counter extends Component {
+    state = useState({ value: 0 });
+
+    increment() {
+        this.state.value++;
+    }
+}
+
+// Main root component
+class App extends Component {
+    static components = { Counter };
+}
+
+//--------------------------------------------------------------------------
+// Patching code
+//--------------------------------------------------------------------------
+
+// In an Odoo application, this code would be located in another odoo module,
+// to customize some behaviour in an existing class/component
+patch(Counter, "double_value", {
+    increment() {
+        this._super();
+        this.state.value = 2 * this.state.value;
+    }
+});
+
+//--------------------------------------------------------------------------
+// Application setup
+//--------------------------------------------------------------------------
+const qweb = new owl.QWeb(TEMPLATES);
+const app = new App({ qweb });
+app.mount(document.body);
+`;
+
+const MONKEYPATCH_XML = `
+<templates>
+  <button t-name="Counter"  t-on-click="increment">
+    Click [<t t-esc="state.value"/>]
+  </button>
+
+  <div t-name="App">
+    <Counter />
+  </div>
+</templates>
+`;
+
+const MONKEYPATCH_CSS = `
+button {
+    font-size: 20px;
+    width: 100px;
+    height: 50px;
+}`;
+
 export const SAMPLES = [
  {
    description: "Components",
@@ -1686,11 +1784,6 @@ export const SAMPLES = [
    xml: HOOKS_DEMO_XML,
    css: HOOKS_CSS
  },
-  {
-    description: "Context",
-    code: CONTEXT_JS,
-    xml: CONTEXT_XML,
-  },
  {
    description: "Todo List App (with store)",
    code: TODO_APP_STORE,
@@ -1720,5 +1813,10 @@ export const SAMPLES = [
    code: ASYNC_COMPONENTS,
    xml: ASYNC_COMPONENTS_XML,
    css: ASYNC_COMPONENTS_CSS
+  }, {
+      description: "Monkey patching components",
+      code: MONKEYPATCH,
+      xml: MONKEYPATCH_XML,
+      css: MONKEYPATCH_CSS
  }
 ];
@@ -31,7 +31,7 @@
            t-att-style="topEditorStyle"/>
        <t t-if="state.splitLayout">
          <div class="separator horizontal"/>
-          <TabbedEditor
+          <TabbedEditor t-keepalive="1"
             js="false"
             css="state.css"
             xml="state.xml"