[REL] v1.0.0-alpha4

Before this rev, using t-component on a div (for example) node
would silently ignore the div and replace it by the root node of
the component. A way to improve this was to create an extra div
node and to put the component inside it. However, it raised
questions: what do we do with other attributes set on this tag?
Do we apply them on the div, or on the component? In addition,
some of them only make sense on the component (e.g. props), so we
have to detect them. Whatever we would have decided, it wouldn't
have been obvious from the user point of view, so we chose not to
support it, and we thus now raise an error in this case.

Closes #487.

README.md

@@ -28,7 +28,7 @@ Owl is currently mostly stable.  Possible future changes are explained in the
 Here is a short example to illustrate interactive components:
 
 ```javascript
-const { Component, QWeb, useState } = owl;
+const { Component, useState } = owl;
 const { xml } = owl.tags;
 
 class Counter extends Component {
@@ -50,7 +50,7 @@ class App extends Component {
   static components = { Counter };
 }
 
-const app = new App({ qweb: new QWeb() });
+const app = new App();
 app.mount(document.body);
 ```
 
@@ -92,7 +92,8 @@ A complete documentation for Owl can be found here:
 
 The most important sections are:
 
-- [Quick Start](doc/quick_start.md)
+- [Tutorial: TodoList application](doc/learning/tutorial_todoapp.md)
+- [QWeb templating language](doc/reference/qweb_templating_language.md)
 - [Component](doc/reference/component.md)
 - [Hooks](doc/reference/hooks.md)
 
@@ -103,8 +104,8 @@ Submit a PR!
 
 If you want to use a simple `<script>` tag, the last release can be downloaded here:
 
-- [owl-0.24.1.js](https://github.com/odoo/owl/releases/download/v0.24.1/owl.js)
-- [owl-0.24.1.min.js](https://github.com/odoo/owl/releases/download/v0.24.1/owl.min.js)
+- [owl-1.0.0-alpha4.js](https://github.com/odoo/owl/releases/download/v1.0.0-alpha3/owl.js)
+- [owl-1.0.0-alpha4.min.js](https://github.com/odoo/owl/releases/download/v1.0.0-alpha3/owl.min.js)
 
 Some npm scripts are available:
 
@@ -127,23 +128,6 @@ 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](doc/reference/qweb.md). 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:
 

doc/architecture/rendering.md

@@ -13,7 +13,6 @@ 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
@@ -21,9 +20,9 @@ There are several classes involved in a rendering:
 - 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`:
+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)
@@ -31,4 +30,3 @@ interface.  Whenever a rendering is initiated in a component `C`:
   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).
-

doc/comparison.md

@@ -274,7 +274,8 @@ class Counter extends Component {
   dispatch = useDispatch();
 }
 
-const counter = new Counter({ store, qweb });
+Counter.env.store = store;
+const counter = new Counter();
 ```
 
 ## Hooks

doc/learning/quick_start.md

@@ -2,8 +2,17 @@
 
 ## Static Server
 
-Let us assume that we have a static server running somewhere. We could then
-simply add an html page with a few extra files.
+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
+```
 
 ### HTML and CSS
 
@@ -88,10 +97,8 @@ class ClickCounter extends owl.Component {
 //------------------------------------------------------------------------------
 async function start() {
   const templates = await owl.utils.loadFile("templates.xml");
-  const env = {
-    qweb: new owl.QWeb({ templates })
-  };
-  const counter = new ClickCounter(env);
+  ClickCounter.env = { qweb: new owl.QWeb({ templates }) };
+  const counter = new ClickCounter();
   const target = document.getElementById("main");
   await counter.mount(target);
 }

doc/readme.md

@@ -1,63 +1,19 @@
 # 🦉 OWL Documentation 🦉
 
-## Owl Content
-
-Owl is a javascript library that contains some core classes and function to help
-build applications. Here is a complete representation of its content:
-
-```
-owl
-    Component
-    Context
-    QWeb
-    Store
-    useState
-    core
-        EventBus
-        Observer
-    hooks
-        onWillStart
-        onMounted
-        onWillUpdateProps
-        onWillPatch
-        onPatched
-        onWillUnmount
-        useContext
-        useState
-        useRef
-        useSubEnv
-        useStore
-        useDispatch
-        useGetters
-    misc
-        AsyncRoot
-    router
-        Link
-        RouteComponent
-        Router
-    tags
-        xml
-    utils
-        debounce
-        escape
-        loadJS
-        loadFile
-        shallowEqual
-        whenReady
-```
-
-Note that for convenience, the `useState` hook is also exported at the root of the `owl` object.
-
 ## 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)
+- [Miscellaneous Components](reference/misc.md)
 - [Observer](reference/observer.md)
-- [QWeb](reference/qweb.md)
+- [Props](reference/props.md)
+- [QWeb Templating Language](reference/qweb_templating_language.md)
+- [QWeb Engine](reference/qweb_engine.md)
 - [Router](reference/router.md)
 - [Store](reference/store.md)
 - [Tags](reference/tags.md)
@@ -65,7 +21,8 @@ Note that for convenience, the `useState` hook is also exported at the root of t
 
 ## Learning Resources
 
-- [Quick Start](quick_start.md)
+- [Quick Start: create an (almost) empty Owl application](learning/quick_start.md)
+- [Tutorial: create a TodoList application](learning/tutorial_todoapp.md)
 
 ## Miscellaneous
 
@@ -75,8 +32,43 @@ Note that for convenience, the `useState` hook is also exported at the root of t
 
 ## Architecture
 
-This section explains in more detail the inner workings of Owl. It is more
-useful for people working on Owl code.
+This section explains in more detail the inner workings of Owl. It is targeted
+for developers working on Owl itself.
 
 - [Virtual DOM](architecture/vdom.md)
 - [Rendering](architecture/rendering.md)
+
+## Owl Content
+
+Here is a complete visual representation of everything exported by the `owl`
+global object (so, for example, `Component` is available at `owl.Component`,
+and `EventBus` is exported as `owl.core.EventBus`):
+
+```
+Component                               misc
+Context                                     AsyncRoot
+QWeb                                    router
+Store                                       Link
+useState                                    RouteComponent
+config                                      Router
+    mode                                tags
+core                                        xml
+    EventBus                            utils
+    Observer                                debounce
+hooks                                       escape
+    onWillStart                             loadJS
+    onMounted                               loadFile
+    onWillUpdateProps                       shallowEqual
+    onWillPatch                             whenReady
+    onPatched
+    onWillUnmount
+    useContext
+    useState
+    useRef
+    useSubEnv
+    useStore
+    useDispatch
+    useGetters
+```
+
+Note that for convenience, the `useState` hook is also exported at the root of the `owl` object.

doc/reference/component.md

@@ -11,15 +11,14 @@
   - [Methods](#methods)
   - [Lifecycle](#lifecycle)
   - [Root Component](#root-component)
-  - [Environment](#environment)
   - [Composition](#composition)
   - [Event Handling](#event-handling)
   - [Form Input Bindings](#form-input-bindings)
-  - [`t-key` Directive](#t-key-directive)
   - [Semantics](#semantics)
   - [Props Validation](#props-validation)
   - [References](#references)
   - [Slots](#slots)
+  - [Dynamic sub components](#dynamic-sub-components)
   - [Asynchronous Rendering](#asynchronous-rendering)
   - [Error Handling](#error-handling)
   - [Functional Components](#functional-components)
@@ -43,7 +42,7 @@ OWL components are the building blocks for user interface. They are designed to
    and follow the QWeb specification. This is a requirement for Odoo.
 
 OWL components are defined as a subclass of Component. The rendering is
-exclusively done by a [QWeb](qweb.md) template (which needs to be preloaded in QWeb).
+exclusively done by a [QWeb](qweb_templating_language.md) template (which needs to be preloaded in QWeb).
 Rendering a component generates a virtual dom representation
 of the component, which is then patched to the DOM, in order to apply the changes in an efficient way.
 
@@ -81,8 +80,8 @@ 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 (`env`), which is propagated from a
-parent to its children. The environment needs to have a QWeb instance, which
+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_templating_language.md) 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
@@ -167,7 +166,7 @@ to be called in the constructor.
 - **`el`** (HTMLElement | null): reference to the DOM root node of the element. It is `null` when the
   component is not mounted.
 
-- **`env`** (Object): the component environment, which contains a QWeb instance.
+- **`env`** (Object): the component [environment](environment.md), 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,
@@ -238,16 +237,15 @@ component.
 
 We explain here all the public methods of the `Component` class.
 
-- **`mount(target, renderBeforeRemount=false)`** (async): this is the main way a
+- **`mount(target)`** (async): this is the main way a
   component is added to the DOM: the root component is mounted to a target
   HTMLElement. Obviously, this is asynchronous, since each children need to be
   created as well. Most applications will need to call `mount` exactly once, on
   the root component.
 
-  The `renderBeforeRemount` argument is useful when a component is unmounted and remounted.
-  In that case, we may want to rerender the component _before_ it is remounted, if
-  we know that its state (or something in the environment, or ...) has changed.
-  In that case, it should simply set to `true`.
+  Note that if a component is mounted, unmounted and remounted, it will be
+  automatically re-rendered to ensure that changes in its state (or something
+  in the environment, or in the store, or ...) will be taken into account.
 
 - **`unmount()`**: in case a component needs to be detached/removed from the DOM, this
   method can be used. Most applications should not call `unmount`, this is more
@@ -392,8 +390,7 @@ 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 (this can
-happen with components with `t-keepalive`).
+DOM state. Also, it will not be called if the component is not in the DOM.
 
 #### `patched(snapshot)`
 
@@ -403,7 +400,7 @@ 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 (this can happen with components with `t-keepalive`).
+not in the DOM.
 
 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
@@ -441,49 +438,17 @@ of an Owl application has to be created manually:
 ```js
 class App extends owl.Component { ... }
 
-const qweb = new owl.QWeb({ templates: TEMPLATES });
-const env = { qweb: qweb };
-const app = new App(env);
+const app = new App();
 app.mount(document.body);
 ```
 
-The root component needs an environment.
+The root component does not have a parent nor `props` (see note below). It will be setup with an
+[environment](environment.md) (either the `env` defined on its class, or a
+default empty 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);
-}
-```
+Note: a root component can however be given a `props` object in its constructor,
+like this: `new App(null, {some: 'object'});`. It will not be a true `props`
+object, managed by Owl (so, for example, it will never be updated).
 
 ### Composition
 
@@ -537,66 +502,8 @@ the static `components` key, then fallbacks on the global registry.
 _Props_: In this example, the child component will receive the object `{count: 4}` in its
 constructor. This will be assigned to the `props` variable, which can be accessed
 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
-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,
-the `t-component` directive can also be used to accept dynamic values with string interpolation (like the [`t-attf-`](qweb.md#dynamic-attributes) directive):
-
-```xml
-<div t-name="ParentComponent">
-    <t t-component="ChildComponent{{id}}" />
-</div>
-```
-
-```js
-class ParentComponent {
-  static components = { ChildComponent1, ChildComponent2 };
-  state = { id: 1 };
-}
-```
-
-And the `t-props` directive can be used to specify totally dynamic props:
-
-```xml
-<div t-name="ParentComponent">
-    <Child t-props="some.obj"/>
-</div>
-```
-
-```js
-class ParentComponent {
-  static components = { Child };
-  some = { obj: { a: 1, b: 2 } };
-}
-```
-
-There is an even more dynamic way to use `t-component`: its value can be an
-expression evaluating to an actual component class. In that case, this is the
-class that will be used to create the component:
-
-```js
-class A extends Component<any, any, any> {
-  static template = xml`<span>child a</span>`;
-}
-class B extends Component<any, any, any> {
-  static template = xml`<span>child b</span>`;
-}
-class App extends Component<any, any, any> {
-  static template = xml`<t t-component="myComponent" t-key="state.child"/>`;
-
-  state = { child: "a" };
-
-  get myComponent() {
-    return this.state.child === "a" ? A : B;
-  }
-}
-```
-
-In this example, the component `App` selects dynamically the concrete sub
-component class.
+the sub component will also be updated automatically. See the [props section](props.md)
+for more information.
 
 **CSS and style:** Owl allows 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
@@ -660,11 +567,13 @@ A _business_ DOM event is triggered by a call to `trigger` on a component.
  }
 ```
 
-The call to `trigger` generates a [_CustomEvent_](https://developer.mozilla.org/docs/Web/Guide/Events/Creating_and_triggering_events)
-of type `menu-loaded` and dispatches it on the component's DOM element
-(`this.el`). The event bubbles and is cancelable. The parent component listening
-to event `menu-loaded` will receive the payload in its `someMethod` handler
-(in the `detail` property of the event), whenever the event is triggered.
+The call to `trigger` generates an `OwlEvent`, a subclass of [_CustomEvent_](https://developer.mozilla.org/docs/Web/Guide/Events/Creating_and_triggering_events)
+with an additional attribute `originalComponent` (the component that triggered
+the event). The generated event is of type `menu-loaded` and dispatches it on
+the component's DOM element (`this.el`). The event bubbles and is cancelable.
+The parent component listening to event `menu-loaded` will receive the payload
+in its `someMethod` handler (in the `detail` property of the event), whenever
+the event is triggered.
 
 ```js
  class ParentComponent {
@@ -822,70 +731,6 @@ update a number whenever the change is done.
 
 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.
-
-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.
-
-Consider the following situation: we have a list of two items `[{text: "a"}, {text: "b"}]`
-and we render them in this template:
-
-```xml
-<p t-foreach="items" t-as="item"><t t-esc="item.text"/></p>
-```
-
-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:
-
-- 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>
-```
-
 ### Semantics
 
 We give here an informal description of the way components are created/updated
@@ -980,13 +825,13 @@ As an application becomes complex, it may be quite unsafe to define props in an
 - 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.
 
-A props type system would solve both issues, by describing the types and shapes
+A props type system solves both issues, by describing the types and shapes
 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 [tooling page](../tooling.md#development-mode))
+- props are only validated in `dev` mode (see [config page](config.md#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.
@@ -1180,6 +1025,51 @@ be considered the `default` slot. For example:
 </div>
 ```
 
+### Dynamic sub components
+
+It is not common, but sometimes we need a dynamic component name. In this case,
+the `t-component` directive can also be used to accept dynamic values with string interpolation (like the [`t-attf-`](qweb_templating_language.md#dynamic-attributes) directive):
+
+```xml
+<div t-name="ParentComponent">
+    <t t-component="ChildComponent{{id}}" />
+</div>
+```
+
+```js
+class ParentComponent {
+  static components = { ChildComponent1, ChildComponent2 };
+  state = { id: 1 };
+}
+```
+
+There is an even more dynamic way to use `t-component`: its value can be an
+expression evaluating to an actual component class. In that case, this is the
+class that will be used to create the component:
+
+```js
+class A extends Component<any, any, any> {
+  static template = xml`<span>child a</span>`;
+}
+class B extends Component<any, any, any> {
+  static template = xml`<span>child b</span>`;
+}
+class App extends Component<any, any, any> {
+  static template = xml`<t t-component="myComponent" t-key="state.child"/>`;
+
+  state = { child: "a" };
+
+  get myComponent() {
+    return this.state.child === "a" ? A : B;
+  }
+}
+```
+
+In this example, the component `App` selects dynamically the concrete sub
+component class.
+
+Note that the `t-component` directive can only be used on `<t>` nodes.
+
 ### Asynchronous Rendering
 
 Working with asynchronous code always adds a lot of complexity to a system. Whenever

doc/reference/config.md

@@ -0,0 +1,27 @@
+# 🦉 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 one key:
+
+- [`mode`](#mode).
+
+## 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.

doc/reference/context.md

@@ -28,10 +28,7 @@ context, and add it to the environment:
 
 ```js
 const deviceContext = new Context({ isMobile: true });
-const env = {
-  qweb: new QWeb({ templates: TEMPLATES }),
-  deviceContext
-};
+App.env.deviceContext = deviceContext;
 ```
 
 If we want to make it completely responsive, we need to update its value whenever
@@ -56,14 +53,14 @@ 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>
-    `;
+    <div>
+      <t t-if=device.isMobile>
+          some simplified user interface
+      </t>
+      <t t-else="1">
+          a more advanced user interface
+      </t>
+    </div>`;
   device = useContext(this.env.deviceContext);
 }
 ```

doc/reference/environment.md

@@ -0,0 +1,105 @@
+# 🦉 Environment 🦉
+
+## Content
+
+- [Overview](#overview)
+- [Setting an Environment](#setting-an-environment)
+- [Content of an Environment](#content-of-an-environment)
+
+## Overview
+
+An environment is an object which contains a [`QWeb` instance](qweb_engine.md). Whenever
+a root component is created, it is assigned an environment (see
+[below](#setting-an-environment) for more info on this). 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. Owl internally requires
+that the environment has a `qweb` key which maps to a
+[`QWeb`](qweb_engine.md) instance. This is the QWeb instance that will be used to
+render each templates in this specific component tree. Note that if no `QWeb`
+instance is provided, Owl will simply generate it on the fly.
+
+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.
+
+## Setting an environment
+
+An Owl application needs an [environment](environment.md) to be executed. The
+environment has an important key: the [QWeb](qweb_engine.md) instance, which will render
+all templates.
+
+Whenever a root component `App` is mounted, Owl will setup a valid environment by
+following the next steps:
+
+- take the `env` object defined on `App.env` (if no `env` was explicitely setup,
+  this will be return the empty `env` object defined on `Component`)
+- if `env.qweb` is not set, then Owl will create a `QWeb` instance.
+
+The correct way to customize an environment is to simply set it up on the root
+component class, before the first component is created:
+
+```js
+App.env = {
+    _t: myTranslateFunction,
+    user: {...},
+    services: {
+        ...
+    },
+};
+const app = new App();
+app.mount(document.body);
+```
+
+It is also possible to simply share an environment between all root components,
+by simply doing this:
+
+```js
+Component.env = myEnv; // will be the default env for all components
+```
+
+## Content of an Environment
+
+Some good use cases for additional keys in the environment are:
+
+- 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() {
+  App.env = await myEnv();
+  const app = new App();
+  await app.mount(document.body);
+}
+```

doc/reference/hooks.md

@@ -290,6 +290,7 @@ class Parent extends Component {
     // here, if component is mounted, refs are active:
     // - this.divRef.el is the div HTMLElement
     // - this.subRef.comp is the instance of the sub component
+    // - this.subRef.el is the root HTML node of the sub component (i.e. this.subRef.comp.el)
   }
 }
 ```
@@ -297,11 +298,14 @@ class Parent extends Component {
 As shown by the example above, html elements are accessed by using the `el`
 key, and components references are accessed with `comp`.
 
-Note: if used on a component, the reference will be set in the `refs`
-variable between `willPatch` and `patched`.
+Notes:
+
+- if used on a component, the reference will be set in the `refs`
+  variable between `willPatch` and `patched`,
+- on a component, accessing `ref.el` will get the root node of the component.
 
 The `t-ref` directive also accepts dynamic values with string interpolation
-(like the [`t-attf-`](qweb.md#dynamic-attributes) and
+(like the [`t-attf-`](qweb_templating_language.md#dynamic-attributes) and
 `t-component` directives). For example,
 
 ```xml

doc/reference/props.md

@@ -0,0 +1,97 @@
+# 🦉 Props 🦉
+
+## Content
+
+- [Overview](#overview)
+- [Definition](#definition)
+- [Good Practices](#good-practices)
+- [Dynamic Props](#dynamic-props)
+
+## Overview
+
+In Owl, `props` (short for _properties_) is an object which contains every piece
+of data given to a component by its parent.
+
+```js
+class Child extends Component {
+  static template = xml`<div><t t-esc="props.a"/><t t-esc="props.b"/></div>`;
+}
+
+class Parent extends Component {
+  static template = xml`<div><ComponentA a="state.a" b="'string'"/></div>`;
+  static components = { Child };
+  state = useState({ a: "fromparent" });
+}
+```
+
+In this example, the `Child` component receives two props from its parent: `a`
+and `b`. They are collected into a `props` object by Owl, with each value being
+evaluated in the context of the parent. So, `props.a` is equal to `'fromparent'` and
+`props.b` is equal to `'string'`.
+
+Note that `props` is an object that only makes sense from the perspective of the
+child component.
+
+## Definition
+
+The `props` object is made of every attributes defined on the template, with the
+following exceptions:
+
+- every attribute starting with `t-` are not props (they are QWeb directives),
+- `style` and `class` attributes are excluded as well (they are applied by Owl on
+  the root element of the component).
+
+In the following example:
+
+```xml
+<div>
+    <ComponentA a="state.a" b="'string'"/>
+    <ComponentB t-if="state.flag" model="model"/>
+    <ComponentC style="color:red;" class="left-pane" />
+</div>
+```
+
+the `props` object contains the following keys:
+
+- for `ComponentA`: `a` and `b`,
+- for `ComponentB`: `model`,
+- for `ComponentC`: empty object
+
+## Good Practices
+
+A `props` object is a collection of values that come from the parent. As such,
+they are owned by the parent, and should never be modified by the child:
+
+```js
+class MyComponent extends Component {
+  constructor(parent, props) {
+    super(parent, props);
+    props.a.b = 43; // Never do that!!!
+  }
+}
+```
+
+Props should be considered readonly, from the perspective of the child component.
+If there is a need to modify them, then the request to update them should be
+sent to the parent (for example, with an event).
+
+Any value can go in a props. Strings, objects, classes, or even callbacks could
+be given to a child component (but then, in the case of callbacks, communicating
+with events seems more appropriate).
+
+## Dynamic Props
+
+The `t-props` directive can be used to specify totally dynamic props:
+
+```xml
+<div t-name="ParentComponent">
+    <Child t-props="some.obj"/>
+</div>
+```
+
+```js
+class ParentComponent {
+  static components = { Child };
+  some = { obj: { a: 1, b: 2 } };
+}
+```

doc/reference/qweb_engine.md

@@ -0,0 +1,151 @@
+# 🦉 QWeb Engine 🦉
+
+## Content
+
+- [Overview](#overview)
+- [Reference](#reference)
+
+## Overview
+
+[QWeb](https://www.odoo.com/documentation/13.0/reference/qweb.html) is the primary
+templating engine used by Odoo. The QWeb class in the OWL project is an
+implementation of that specification with a few interesting points:
+
+- it compiles templates into functions that output a virtual DOM instead of a
+  string. This is necessary for the component system.
+- it has a few extra directives: `t-component`, `t-on`, ...
+
+We present in this section the engine, not the templating language.
+
+## Reference
+
+This section is about the javascript code that implements the `QWeb` specification.
+Owl exports a `QWeb` class in `owl.QWeb`. To use it, it just needs to be
+instantiated:
+
+```js
+const qweb = new owl.QWeb();
+```
+
+Its 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)).
+
+  ```js
+  const qweb = new owl.QWeb({ templates: TEMPLATES, translateFn: _t });
+  ```
+
+- **`addTemplate(name, xmlStr, allowDuplicate)`**: add a specific template.
+
+  ```js
+  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.
+
+- **`addTemplates(xmlStr)`**: add a list of templates (identified by `t-name`
+  attribute).
+
+  ```js
+  const TEMPLATES = `
+    <templates>
+      <div t-name="App" class="main">main</div>
+      <div t-name="OtherComponent">other component</div>
+    </templates>`;
+  qweb.addTemplates(TEMPLATES);
+  ```
+
+- **`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)).
+
+  ```js
+  const vnode = qweb.render("App", component);
+  ```
+
+- **`renderToString(name, context)`**: renders a template, but returns an html
+  string.
+
+  ```js
+  const str = qweb.renderToString("someTemplate", somecontext);
+  ```
+
+- **`registerTemplate(name, template)`**: static function to register a 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>`);
+  ```
+
+- **`registerComponent(name, Component)`**: static function to register an OWL Component
+  to QWeb's global registry. Globally registered Components can be used in
+  templates (see the `t-component` directive). This is useful for commonly used
+  components accross the application.
+
+  ```js
+  class Dialog extends owl.Component { ... }
+  QWeb.registerComponent("Dialog", Dialog);
+
+  ...
+
+  class ParentComponent extends owl.Component { ... }
+  qweb.addTemplate("ParentComponent", "<div><Dialog/></div>");
+  ```
+
+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
+between Owl classes. This is the reason why `QWeb` actually extends [EventBus](event_bus.md).
+
+### 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.

doc/reference/qweb_templating_language.md

@@ -1,10 +1,9 @@
-# 🦉 QWeb 🦉
+# 🦉 QWeb Templating Language🦉
 
 ## Content
 
 - [Overview](#overview)
 - [Directives](#directives)
-- [QWeb Engine](#qweb-engine)
 - [Reference](#reference)
   - [White Spaces](#white-spaces)
   - [Root Nodes](#root-nodes)
@@ -21,14 +20,11 @@
 
 ## 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/13.0/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.
 
-Template directives are specified as XML attributes prefixed with `t-`, for instance `t-if` for conditionals, with elements and other attributes being rendered directly.
-
-To avoid element rendering, a placeholder element `<t>` is also available, which executes its directive but doesn’t generate any output in and of itself.
-
 ```xml
 <div>
     <span t-if="somecondition">Some string</span>
@@ -40,135 +36,48 @@ To avoid element rendering, a placeholder element `<t>` is also available, which
 </div>
 ```
 
-The QWeb class in the OWL project is an implementation of that specification
-with a few interesting points:
+Template directives are specified as XML attributes prefixed with `t-`, for
+instance `t-if` for conditionals, with elements and other attributes being
+rendered directly.
 
-- it compiles templates into functions that output a virtual DOM instead of a
-  string. This is necessary for the component system.
-- it has a few extra directives: `t-component`, `t-on`, ...
+To avoid element rendering, a placeholder element `<t>` is also available, which
+executes its directive but doesn’t generate any output in and of itself.
+
+We present in this section the templating language, including its Owl specific
+extensions.
 
 ## Directives
 
-We present here a list of all standard QWeb directives:
+For reference, here is a list of all standard QWeb directives:
 
-| Name                           | Description                                                  |
-| ------------------------------ | ------------------------------------------------------------ |
-| `t-esc`                        | [Outputting safely a value](#outputting-data)                |
-| `t-raw`                        | [Outputting value, without escaping](#outputting-data)       |
-| `t-set`, `t-value`             | [Setting variables](#setting-variables)                      |
-| `t-if`, `t-elif`, `t-else`,    | [conditionally rendering](#conditionals)                     |
-| `t-foreach`, `t-as`            | [Loops](#loops)                                              |
-| `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) |
+| Name                           | Description                                                    |
+| ------------------------------ | -------------------------------------------------------------- |
+| `t-esc`                        | [Outputting safely a value](#outputting-data)                  |
+| `t-raw`                        | [Outputting value, without escaping](#outputting-data)         |
+| `t-set`, `t-value`             | [Setting variables](#setting-variables)                        |
+| `t-if`, `t-elif`, `t-else`,    | [conditionally rendering](#conditionals)                       |
+| `t-foreach`, `t-as`            | [Loops](#loops)                                                |
+| `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.md) |
 
 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`, `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
-
-This section is about the javascript code that implements the `QWeb` specification.
-Owl exports a `QWeb` class in `owl.QWeb`. To use it, it just needs to be
-instantiated:
-
-```js
-const qweb = new owl.QWeb();
-```
-
-Its 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)).
-
-  ```js
-  const qweb = new owl.QWeb({ templates: TEMPLATES, translateFn: _t });
-  ```
-
-- **`addTemplate(name, xmlStr, allowDuplicate)`**: add a specific template.
-
-  ```js
-  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.
-
-- **`addTemplates(xmlStr)`**: add a list of templates (identified by `t-name`
-  attribute).
-
-  ```js
-  const TEMPLATES = `
-    <templates>
-      <div t-name="App" class="main">main</div>
-      <div t-name="OtherComponent">other component</div>
-    </templates>`;
-  qweb.addTemplates(TEMPLATES);
-  ```
-
-- **`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)).
-
-  ```js
-  const vnode = qweb.render("App", component);
-  ```
-
-- **`renderToString(name, context)`**: renders a template, but returns an html
-  string.
-
-  ```js
-  const str = qweb.renderToString("someTemplate", somecontext);
-  ```
-
-- **`registerTemplate(name, template)`**: static function to register a 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>`);
-  ```
-
-- **`registerComponent(name, Component)`**: static function to register an OWL Component
-  to QWeb's global registry. Globally registered Components can be used in
-  templates (see the `t-component` directive). This is useful for commonly used
-  components accross the application.
-
-  ```js
-  class Dialog extends owl.Component { ... }
-  QWeb.registerComponent("Dialog", Dialog);
-
-  ...
-
-  class ParentComponent extends owl.Component { ... }
-  qweb.addTemplate("ParentComponent", "<div><Dialog/></div>");
-  ```
-
-In some way, a `QWeb` instance is the core of an Owl application. It is the only
-mandatory element of an [environment](component.md#environment). As such, it
-has an extra responsibility: 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).
+| 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)](#loops)                   |
+| `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)                         |
 
 ## Reference
 
-We define in this section the specification of how `QWeb` templates should be
-rendered. Note that we only document here the standard QWeb specification. Owl
-specific extensions are documented in various other parts of the documentation.
-
 ### White Spaces
 
 White spaces in a template are handled in a special way:
@@ -479,16 +388,66 @@ into the global context.
 <!-- 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).
+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.
+
+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.
+
+Consider the following situation: we have a list of two items `[{text: "a"}, {text: "b"}]`
+and we render them in this template:
 
 ```xml
-<p t-foreach="state.things" t-as="thing" t-key="thing.id">
-    <t t-esc="thing.content"/>
+<p t-foreach="items" t-as="item"><t t-esc="item.text"/></p>
+```
+
+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:
+
+- 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>
 ```
 
 If there is no `t-key` directive, Owl will use the index as a default key.
@@ -543,23 +502,9 @@ will result in :
 
 ### 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`:
+By default, QWeb specify that templates should be translated. If this behaviour
+is not wanted, there is a `t-translation` directive which can turn off
+translations (if it is set to the `off` value), with the following rules:
 
 - each text node will be replaced with its translation,
 - each of the following attribute values will be translated as well: `title`,
@@ -567,26 +512,8 @@ Once setup, all rendered templates will be translated using `translateFn`:
 - 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.
+See [here](qweb_engine.md#translations) for more information on how to setup a
+translate function in Owl QWeb.
 
 ### Debugging
 

doc/reference/router.md

@@ -67,6 +67,9 @@ function makeEnvironment() {
     await env.router.start();
     return env;
 }
+
+App.env = makeEnvironment();
+// create root component here
 ```
 
 Notice that the router needs to be started. This is an asynchronous operation

doc/reference/store.md

@@ -263,7 +263,7 @@ will perform a strict equality check and will update the component every time th
 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
+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`

doc/tooling.md

@@ -3,7 +3,6 @@
 ## Content
 
 - [Overview](#overview)
-- [Development Mode](#development-mode)
 - [Playground](#playground)
 - [Benchmarks](#benchmarks)
 - [Single File Component](#single-file-component)
@@ -21,26 +20,6 @@ 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
@@ -65,7 +44,7 @@ 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).
+helper. With this, a template is automatically registered to [QWeb](reference/qweb_engine.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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "owl-framework",
-  "version": "0.24.1",
+  "version": "1.0.0-alpha4",
   "description": "Odoo Web Library (OWL)",
   "main": "src/index.ts",
   "engines": {
@@ -18,7 +18,7 @@
     "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,tests/**/*.ts,doc/**/*.md} --write"
+    "prettier": "prettier {src/*.ts,src/**/*.ts,tests/*.ts,tests/**/*.ts,doc/*.md,doc/**/*.md} --write"
   },
   "repository": {
     "type": "git",
@@ -44,7 +44,7 @@
     "sass": "^1.16.1",
     "source-map-support": "^0.5.10",
     "ts-jest": "^23.10.5",
-    "typescript": "^3.6.4",
+    "typescript": "^3.7.2",
     "uglify-es": "^3.3.9"
   },
   "jest": {

roadmap.md

@@ -1,23 +1,25 @@
 # 🦉 OWL Roadmap 🦉
 
-- Current version: 0.24.1
+- Current version: 1.0.0-alpha4
 - Status: mostly stable
 
 This roadmap is only an attempt at predicting Owl's future.  Everything may
 change!
 
-### October 2019
-
-We plan to complete the following tasks:
-
-- improve API for root widgets (issue #306),
-- replace `t-keepalive`, and maybe `t-transition` by components (issue #295).
 
 ### November 2019
 
-Once the previous tasks are done, release version 1.0alpha. This means that the
-API should be stable.  But it could change a little bit if we need it for our
-work on Odoo.
+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
 

src/component/component.ts

@@ -1,10 +1,11 @@
 import { Observer } from "../core/observer";
+import { OwlEvent } from "../core/owl_event";
 import { CompiledTemplate, QWeb } from "../qweb/index";
-import { h, patch, VNode } from "../vdom/index";
+import { patch, VNode } from "../vdom/index";
 import "./directive";
 import { Fiber } from "./fiber";
 import "./props_validation";
-import { Scheduler } from "./scheduler";
+import { Scheduler, scheduler } from "./scheduler";
 
 /**
  * Owl Component System
@@ -20,8 +21,6 @@ import { Scheduler } from "./scheduler";
 //------------------------------------------------------------------------------
 // Types/helpers
 //------------------------------------------------------------------------------
-const raf = window.requestAnimationFrame.bind(window);
-export const scheduler = new Scheduler(raf);
 
 /**
  * An Env (environment) is an object that will be (mostly) shared between all
@@ -46,6 +45,7 @@ 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;
@@ -61,6 +61,9 @@ interface Internal<T extends Env, Props> {
   cmap: { [key: number]: number };
 
   currentFiber: Fiber | null;
+  // parentLastFiberId is there to help the parent component to detect, among
+  // its children, those that are not used anymore and thus can be destroyed
+  parentLastFiberId: number;
 
   boundHandlers: { [key: number]: any };
   observer: Observer | null;
@@ -88,6 +91,9 @@ export class Component<T extends Env, Props extends {}> {
   static components = {};
   static props?: any;
   static defaultProps?: any;
+  static env: any = {};
+  // expose scheduler s.t. it can be mocked for testing purposes
+  static scheduler: Scheduler = scheduler;
 
   /**
    * The `el` is the root element of the component.  Note that it could be null:
@@ -107,44 +113,37 @@ 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> | T, props?: Props) {
-    const defaultProps = (<any>this.constructor).defaultProps;
+  constructor(parent?: Component<T, any> | null, props?: Props) {
     Component.current = this;
+
+    let constr = this.constructor as any;
+    const defaultProps = constr.defaultProps;
     if (defaultProps) {
-      props = this.__applyDefaultProps(props, defaultProps);
+      props = props || ({} as 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>{};
+    this.props = <Props>props;
     if (QWeb.dev) {
-      QWeb.utils.validateProps(this.constructor, this.props);
+      QWeb.utils.validateProps(constr, this.props);
     }
-    let id: number = nextId++;
-    let p: Component<T, any> | null = null;
-    if (parent instanceof Component) {
-      p = parent;
+
+    const id: number = nextId++;
+    let depth;
+    if (parent) {
       this.env = parent.env;
-      parent.__owl__.children[id] = this;
+      const __powl__ = parent.__owl__;
+      __powl__.children[id] = this;
+      depth = __powl__.depth + 1;
     } else {
-      this.env = parent;
+      // we are the root component
+      this.env = (this.constructor as any).env;
+      if (!this.env.qweb) {
+        this.env.qweb = new QWeb();
+      }
       this.env.qweb.on("update", this, () => {
         if (this.__owl__.isMounted) {
           this.render(true);
@@ -158,19 +157,23 @@ export class Component<T extends Env, Props extends {}> {
           this.env.qweb.off("update", this);
         }
       });
+      depth = 0;
     }
-    const qweb = this.env.qweb;
 
+    const qweb = this.env.qweb;
+    const template = constr.template || this.__getTemplate(qweb);
     this.__owl__ = {
       id: id,
+      depth: depth,
       vnode: null,
       pvnode: null,
       isMounted: false,
       isDestroyed: false,
-      parent: p,
+      parent: parent || null,
       children: {},
       cmap: {},
       currentFiber: null,
+      parentLastFiberId: 0,
       boundHandlers: {},
       mountedCB: null,
       willUnmountCB: null,
@@ -179,7 +182,7 @@ export class Component<T extends Env, Props extends {}> {
       willStartCB: null,
       willUpdatePropsCB: null,
       observer: null,
-      renderFn: qweb.render.bind(qweb, this.__getTemplate(qweb)),
+      renderFn: qweb.render.bind(qweb, template),
       classObj: null,
       refs: null
     };
@@ -278,40 +281,23 @@ export class Component<T extends Env, Props extends {}> {
    *
    * Note that a component can be mounted an unmounted several times
    */
-  async mount(target: HTMLElement, renderBeforeRemount: boolean = false): Promise<void> {
+  async mount(target: HTMLElement): 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;
+    if (!(target instanceof HTMLElement)) {
+      let message = `Component '${this.constructor.name}' cannot be mounted: the target is not a valid DOM node.`;
+      message += `\nMaybe the DOM is not ready yet? (in that case, you can use owl.utils.whenReady)`;
+      throw new Error(message);
     }
-    const fiber = new Fiber(null, this, this.props, undefined, undefined, false);
+    const fiber = new Fiber(null, this, undefined, undefined, false, target);
     if (!__owl__.vnode) {
       this.__prepareAndRender(fiber);
     } else {
       this.__render(fiber);
     }
-    return new Promise((resolve, reject) => {
-      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();
-      });
-    });
+    return scheduler.addFiber(fiber);
   }
 
   /**
@@ -336,26 +322,34 @@ 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 && !__owl__.currentFiber) {
+      // if we get here, this means that the component was either never mounted,
+      // or was unmounted and some state change  triggered a render. Either way,
+      // we do not want to actually render anything in this case.
       return;
     }
-    const fiber = new Fiber(null, this, this.props, undefined, undefined, force);
-    this.__render(fiber);
-    return new Promise((resolve, reject) => {
-      scheduler.addFiber(fiber.root, err => {
-        if (err) {
-          reject(err);
-          return;
-        }
-        if (__owl__.isMounted && fiber === fiber.root) {
-          fiber.patchComponents();
-        }
-        resolve();
-      });
+    if (__owl__.currentFiber && !__owl__.currentFiber.isRendered) {
+      return scheduler.addFiber(__owl__.currentFiber.root);
+    }
+    // if we aren't mounted at this point, it implies that there is a
+    // currentFiber that is already rendered (isRendered is true), so we are
+    // about to be mounted
+    const isMounted = __owl__.isMounted;
+    const fiber = new Fiber(null, this, undefined, undefined, force, null);
+    Promise.resolve().then(() => {
+      if (__owl__.isMounted || !isMounted) {
+        // we are mounted (__owl__.isMounted), or if we are currently being
+        // mounted (!isMounted), so we call __render
+        this.__render(fiber);
+      } else {
+        // we were mounted when render was called, but we aren't anymore, so we
+        // were actually about to be unmounted ; we can thus forget about this
+        // fiber
+        fiber.isCompleted = true;
+        __owl__.currentFiber = null;
+      }
     });
+    return scheduler.addFiber(fiber);
   }
 
   /**
@@ -395,7 +389,7 @@ export class Component<T extends Env, Props extends {}> {
    */
   trigger(eventType: string, payload?: any) {
     if (this.el) {
-      const ev = new CustomEvent(eventType, {
+      const ev = new OwlEvent(this, eventType, {
         bubbles: true,
         cancelable: true,
         detail: payload
@@ -440,6 +434,9 @@ export class Component<T extends Env, Props extends {}> {
     }
     __owl__.isDestroyed = true;
     delete __owl__.vnode;
+    if (__owl__.currentFiber) {
+      __owl__.currentFiber.isCompleted = true;
+    }
   }
 
   __callMounted() {
@@ -452,13 +449,10 @@ export class Component<T extends Env, Props extends {}> {
       }
     }
     __owl__.isMounted = true;
-    try {
-      this.mounted();
-      if (__owl__.mountedCB) {
-        __owl__.mountedCB();
-      }
-    } catch (e) {
-      console.error(e); // TODO : add a test
+    __owl__.currentFiber = null;
+    this.mounted();
+    if (__owl__.mountedCB) {
+      __owl__.mountedCB();
     }
   }
 
@@ -492,7 +486,7 @@ export class Component<T extends Env, Props extends {}> {
     const shouldUpdate = parentFiber.force || this.shouldUpdate(nextProps);
     if (shouldUpdate) {
       const __owl__ = this.__owl__;
-      const fiber = new Fiber(parentFiber, this, this.props, scope, vars, parentFiber.force);
+      const fiber = new Fiber(parentFiber, this, scope, vars, parentFiber.force, null);
       if (!parentFiber.child) {
         parentFiber.child = fiber;
       } else {
@@ -501,7 +495,7 @@ export class Component<T extends Env, Props extends {}> {
 
       const defaultProps = (<any>this.constructor).defaultProps;
       if (defaultProps) {
-        nextProps = this.__applyDefaultProps(nextProps, defaultProps);
+        this.__applyDefaultProps(nextProps, defaultProps);
       }
       if (QWeb.dev) {
         QWeb.utils.validateProps(this.constructor, nextProps);
@@ -510,7 +504,7 @@ export class Component<T extends Env, Props extends {}> {
         this.willUpdateProps(nextProps),
         __owl__.willUpdatePropsCB && __owl__.willUpdatePropsCB(nextProps)
       ]);
-      if (fiber.isCancelled) {
+      if (fiber.isCompleted) {
         return;
       }
       this.props = nextProps;
@@ -527,7 +521,6 @@ 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;
   }
 
   /**
@@ -536,7 +529,7 @@ export class Component<T extends Env, Props extends {}> {
    * parent template.
    */
   __prepare(parentFiber: Fiber, scope: any, vars: any, previousSibling?: Fiber | null) {
-    const fiber = new Fiber(parentFiber, this, this.props, scope, vars, parentFiber.force);
+    const fiber = new Fiber(parentFiber, this, scope, vars, parentFiber.force, null);
     fiber.shouldPatch = false;
     if (!parentFiber.child) {
       parentFiber.child = fiber;
@@ -549,22 +542,18 @@ export class Component<T extends Env, Props extends {}> {
   __getTemplate(qweb: QWeb): string {
     let p = (<any>this).constructor;
     if (!p.hasOwnProperty("_template")) {
-      if (p.template) {
-        p._template = p.template;
-      } else {
-        // here, the component and none of its superclasses defines a static `template`
-        // key. So we fall back on looking for a template matching its name (or
-        // one of its subclass).
+      // here, the component and none of its superclasses defines a static `template`
+      // key. So we fall back on looking for a template matching its name (or
+      // one of its subclass).
 
-        let template: string;
-        while ((template = p.name) && !(template in qweb.templates) && p !== Component) {
-          p = p.__proto__;
-        }
-        if (p === Component) {
-          throw new Error(`Could not find template for component "${this.constructor.name}"`);
-        } else {
-          p._template = template;
-        }
+      let template: string;
+      while ((template = p.name) && !(template in qweb.templates) && p !== Component) {
+        p = p.__proto__;
+      }
+      if (p === Component) {
+        throw new Error(`Could not find template for component "${this.constructor.name}"`);
+      } else {
+        p._template = template;
       }
     }
     return p._template;
@@ -574,13 +563,12 @@ export class Component<T extends Env, Props extends {}> {
       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) {
+    if (!fiber.isCompleted) {
       this.__render(fiber);
     }
   }
@@ -590,29 +578,45 @@ export class Component<T extends Env, Props extends {}> {
     if (__owl__.observer) {
       __owl__.observer.allowMutations = false;
     }
-    let vnode;
+    let error;
     try {
-      vnode = __owl__.renderFn!(this, {
+      let vnode = __owl__.renderFn!(this, {
         handlers: __owl__.boundHandlers,
         fiber: fiber
       });
+      // we iterate over the children to detect those that no longer belong to the
+      // current rendering: those ones, if not mounted yet, can (and have to) be
+      // destroyed right now, because they are not in the DOM, and thus we won't
+      // be notified later on (when patching), that they are removed from the DOM
+      for (let childKey in __owl__.children) {
+        let child = __owl__.children[childKey];
+        if (!child.__owl__.isMounted && child.__owl__.parentLastFiberId < fiber.id) {
+          child.destroy();
+        }
+      }
+      if (!vnode) {
+        throw new Error(`Rendering '${this.constructor.name}' did not return anything`);
+      }
+      fiber.vnode = vnode;
+      // we apply here the class information described on the component by the
+      // template (so, something like <MyComponent class="..."/>) to the actual
+      // root vnode
+      if (__owl__.classObj) {
+        const data = vnode.data!;
+        data.class = Object.assign(data.class || {}, __owl__.classObj);
+      }
     } catch (e) {
-      vnode = __owl__.vnode || h("div");
-      fiber.handleError(e);
+      error = e;
     }
-    fiber.vnode = vnode;
     if (__owl__.observer) {
       __owl__.observer.allowMutations = true;
     }
 
-    // we apply 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;
+    if (error) {
+      fiber.handleError(error);
+    }
   }
 
   /**
@@ -649,16 +653,13 @@ export class Component<T extends Env, Props extends {}> {
   /**
    * Apply default props (only top level).
    *
-   * Note that this method does not modify in place the props, it returns a new
-   * prop object
+   * Note that this method does modify in place the props
    */
-  __applyDefaultProps(props: Object | undefined, defaultProps: Object): Props {
-    props = props ? Object.assign({}, props) : {};
+  __applyDefaultProps(props: Object, defaultProps: Object) {
     for (let propName in defaultProps) {
       if (props![propName] === undefined) {
         props![propName] = defaultProps[propName];
       }
     }
-    return <Props>props;
   }
 }

src/component/directive.ts

@@ -186,7 +186,7 @@ QWeb.utils.defineProxy = function defineProxy(target, source) {
 
 QWeb.addDirective({
   name: "component",
-  extraNames: ["props", "keepalive"],
+  extraNames: ["props"],
   priority: 100,
   atNodeEncounter({ ctx, value, node, qweb }): boolean {
     ctx.addLine("//COMPONENT");
@@ -194,7 +194,6 @@ 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;
 
     // t-on- events and t-transition
@@ -230,19 +229,7 @@ QWeb.addDirective({
     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}}__`;
-    }
-    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} = ${locationExpr};`);
-    }
-    const templateId = `templateId${componentID}`;
-
+    const templateKey = ctx.generateTemplateKey();
     let ref = node.getAttribute("t-ref");
     let refExpr = "";
     let refKey: string = "";
@@ -256,8 +243,8 @@ QWeb.addDirective({
     if (transition) {
       transitionsInsertCode = `utils.transitionInsert(vn, '${transition}');`;
     }
-    let finalizeComponentCode = `w${componentID}.${keepAlive ? "unmount" : "destroy"}();`;
-    if (ref && !keepAlive) {
+    let finalizeComponentCode = `w${componentID}.destroy();`;
+    if (ref) {
       finalizeComponentCode += `delete context.__owl__.refs[${refKey}];`;
     }
     if (transition) {
@@ -335,14 +322,9 @@ QWeb.addDirective({
     }
 
     ctx.addLine(
-      `let w${componentID} = ${templateId} in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[${templateId}]] : false;`
+      `let w${componentID} = ${templateKey} in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[${templateKey}]] : false;`
     );
     let shouldProxy = !ctx.parentNode;
-    if (keepAlive) {
-      ctx.addLine(
-        `const fiber${componentID} = Object.assign(Object.create(extra.fiber), {patchQueue: []});`
-      );
-    }
     if (shouldProxy) {
       let id = ctx.generateID();
       ctx.rootContext.rootNode = id;
@@ -393,28 +375,15 @@ QWeb.addDirective({
     ctx.addIf(`w${componentID}`);
 
     // need to update component
-    let patchQueueCode = 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${componentID}`;
-    }
     let styleCode = "";
     if (tattStyle) {
       styleCode = `.then(()=>{if (w${componentID}.__owl__.isDestroyed) {return};w${componentID}.el.style=${tattStyle};});`;
     }
     ctx.addLine(
-      `w${componentID}.__updateProps(props${componentID}, ${patchQueueCode}${scopeVars &&
+      `w${componentID}.__updateProps(props${componentID}, extra.fiber${scopeVars &&
         ", " + scopeVars}, sibling)${styleCode};`
     );
     ctx.addLine(`let pvnode = w${componentID}.__owl__.pvnode;`);
-    let keepAliveCode = "";
-    if (keepAlive) {
-      keepAliveCode = `pvnode.data.hook.insert = vn => {vn.elm.parentNode.replaceChild(w${componentID}.el,vn.elm);vn.elm=w${componentID}.el;w${componentID}.__remount();};`;
-      ctx.addLine(keepAliveCode);
-    }
     if (registerCode) {
       ctx.addLine(registerCode);
     }
@@ -440,7 +409,7 @@ QWeb.addDirective({
       `if (!W${componentID}) {throw new Error('Cannot find the definition of component "' + componentKey${componentID} + '"')}`
     );
     ctx.addLine(`w${componentID} = new W${componentID}(parent, props${componentID});`);
-    ctx.addLine(`parent.__owl__.cmap[${templateId}] = w${componentID}.__owl__.id;`);
+    ctx.addLine(`parent.__owl__.cmap[${templateKey}] = w${componentID}.__owl__.id;`);
 
     if (hasSlots) {
       const clone = <Element>node.cloneNode(true);
@@ -470,11 +439,11 @@ QWeb.addDirective({
     ctx.addLine(`let def${defID} = w${componentID}.__prepare(extra.fiber, ${scopeVars}, sibling);`);
     // 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}}}});`
+      `let pvnode = h('dummy', {key: ${templateKey}, hook: {insert(vn) { let nvn=w${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; ${createHook}});`
+      `def${defID}.then(function () { if (fiber.isCompleted) { return; } const vnode = fiber.vnode; pvnode.sel = vnode.sel; ${createHook}});`
     );
     if (registerCode) {
       ctx.addLine(registerCode);
@@ -490,6 +459,7 @@ QWeb.addDirective({
       ctx.addLine(`w${componentID}.__owl__.classObj=${classObj};`);
     }
 
+    ctx.addLine(`w${componentID}.__owl__.parentLastFiberId = extra.fiber.id;`);
     ctx.addLine(`sibling = w${componentID}.__owl__.currentFiber || sibling;`);
 
     return true;

src/component/fiber.ts

@@ -1,5 +1,6 @@
-import { VNode } from "../vdom/index";
+import { h, VNode } from "../vdom/index";
 import { Component } from "./component";
+import { scheduler } from "./scheduler";
 
 /**
  * Owl Fiber Class
@@ -15,13 +16,17 @@ import { Component } from "./component";
  */
 
 export class Fiber {
+  static nextId: number = 1;
+  id: number = Fiber.nextId++;
+
   // 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;
+  // isCompleted means that the rendering corresponding to this fiber's work is
+  // done, either because the component has been mounted or patched, or because
+  // fiber has been cancelled.
+  isCompleted: boolean = false;
 
   // the fibers corresponding to component updates (updateProps) need to call
   // the willPatch and patched hooks from the corresponding component. However,
@@ -41,9 +46,10 @@ export class Fiber {
   // scheduler.
   counter: number = 0;
 
+  target: HTMLElement | null;
+
   scope: any;
   vars: any;
-  props: any;
 
   component: Component<any, any>;
   vnode: VNode | null = null;
@@ -55,19 +61,25 @@ export class Fiber {
 
   error?: Error;
 
-  constructor(parent: Fiber | null, component: Component<any, any>, props, scope, vars, force) {
+  constructor(parent: Fiber | null, component: Component<any, any>, scope, vars, force, target) {
     this.force = force;
     this.scope = scope;
     this.vars = vars;
-    this.props = props;
     this.component = component;
+    this.target = target;
 
     this.root = parent ? parent.root : this;
     this.parent = parent;
 
     let oldFiber = component.__owl__.currentFiber;
-    if (oldFiber && !oldFiber.isCancelled) {
-      this._remapFiber(oldFiber);
+    if (oldFiber && !oldFiber.isCompleted) {
+      if (oldFiber.root === oldFiber && !parent) {
+        // both oldFiber and this fiber are root fibers
+        this._reuseFiber(oldFiber);
+        return oldFiber;
+      } else {
+        this._remapFiber(oldFiber);
+      }
     }
 
     this.root.counter++;
@@ -75,6 +87,27 @@ export class Fiber {
     component.__owl__.currentFiber = this;
   }
 
+  /**
+   * When the oldFiber is not completed yet, and both oldFiber and this fiber
+   * are root fibers, we want to reuse the oldFiber instead of creating a new
+   * one. Doing so will guarantee that the initiator(s) of those renderings will
+   * be notified (the promise will resolve) when the last rendering will be done.
+   *
+   * This function thus assumes that oldFiber is a root fiber.
+   */
+  _reuseFiber(oldFiber: Fiber) {
+    oldFiber.cancel(); // cancel children fibers
+    oldFiber.isCompleted = false; // keep the root fiber alive
+    oldFiber.isRendered = false; // the fiber has to be re-rendered
+    if (oldFiber.child) {
+      // remove relation to children
+      oldFiber.child.parent = null;
+      oldFiber.child = null;
+    }
+    oldFiber.counter = 1; // re-initialize counter
+    oldFiber.id = Fiber.nextId++;
+  }
+
   /**
    * 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
@@ -84,7 +117,7 @@ export class Fiber {
   _remapFiber(oldFiber: Fiber) {
     oldFiber.cancel();
     if (oldFiber === oldFiber.root) {
-      oldFiber.root.counter++;
+      oldFiber.counter++;
     }
     if (oldFiber.parent && !this.parent) {
       // re-map links
@@ -133,7 +166,26 @@ export class Fiber {
   }
 
   /**
-   * Apply the given patch queue from a fiber.
+   * Successfully complete the work of the fiber: call the mount or patch hooks
+   * and patch the DOM. This function is called once the fiber and its children
+   * are ready, and the scheduler decides to process it.
+   */
+  complete() {
+    const component = this.component;
+    if (this.target) {
+      component.__patch(this.vnode);
+      this.target.appendChild(component.el!);
+      if (document.body.contains(this.target)) {
+        component.__callMounted();
+      }
+    } else if (component.__owl__.isMounted && this === this.root) {
+      this.patchComponents();
+    }
+    this.isCompleted = true;
+  }
+
+  /**
+   * Compute and apply the patch queue of the 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
@@ -143,38 +195,31 @@ export class Fiber {
     const doWork: (Fiber) => Fiber | null = function(f) {
       if (f.shouldPatch) {
         patchQueue.push(f);
+        return f.child;
       }
-      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();
+    for (let i = 0; i < patchLen; i++) {
+      component = patchQueue[i].component;
+      if (component.__owl__.willPatchCB) {
+        component.__owl__.willPatchCB();
       }
-    } catch (e) {
-      console.error(e);
+      component.willPatch();
     }
     for (let i = 0; i < patchLen; i++) {
       const fiber = patchQueue[i];
       component = fiber.component;
       component.__patch(fiber.vnode);
+      component.__owl__.currentFiber = null;
     }
-    try {
-      for (let i = patchLen - 1; i >= 0; i--) {
-        component = patchQueue[i].component;
-        component.patched();
-        if (component.__owl__.patchedCB) {
-          component.__owl__.patchedCB();
-        }
+    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);
     }
   }
 
@@ -186,7 +231,7 @@ export class Fiber {
       if (!f.isRendered) {
         f.root.counter--;
       }
-      f.isCancelled = true;
+      f.isCompleted = true;
       return f.child;
     });
   }
@@ -200,10 +245,12 @@ export class Fiber {
    * being in a corrupted state.
    */
   handleError(error: Error) {
-    let canCatch = false;
     let component = this.component;
-    let qweb = component.env.qweb;
+    this.vnode = component.__owl__.vnode || h("div");
+
+    const qweb = component.env.qweb;
     let root = component;
+    let canCatch = false;
     while (component && !(canCatch = !!component.catchError)) {
       root = component;
       component = component.__owl__.parent!;
@@ -211,12 +258,13 @@ export class Fiber {
     qweb.trigger("error", error);
 
     if (canCatch) {
-      setTimeout(() => {
-        console.error(error);
-        component.catchError!(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();
     }
   }

src/component/props_validation.ts

@@ -40,7 +40,13 @@ QWeb.utils.validateProps = function(Widget, props: Object) {
           break;
         }
       }
-      let isValid = isValidProp(props[propName], propsDef[propName]);
+      let isValid;
+      try {
+        isValid = isValidProp(props[propName], propsDef[propName]);
+      } catch (e) {
+        e.message = `Invalid prop '${propName}' in component ${Widget.name} (${e.message})`;
+        throw e;
+      }
       if (!isValid) {
         throw new Error(`Props '${propName}' of invalid type in component '${Widget.name}'`);
       }
@@ -80,17 +86,27 @@ function isValidProp(prop, propDef): boolean {
     return result;
   }
   // propsDef is an object
+  if (propDef.optional && prop === undefined) {
+    return true;
+  }
   let result = isValidProp(prop, propDef.type);
-  if (propDef.type === Array) {
+  if (propDef.type === Array && propDef.element) {
     for (let i = 0, iLen = prop.length; i < iLen; i++) {
       result = result && isValidProp(prop[i], propDef.element);
     }
   }
-  if (propDef.type === Object) {
+  if (propDef.type === Object && propDef.shape) {
     const shape = propDef.shape;
     for (let key in shape) {
       result = result && isValidProp(prop[key], shape[key]);
     }
+    if (result) {
+      for (let propName in prop) {
+        if (!(propName in shape)) {
+          throw new Error(`unknown prop '${propName}'`);
+        }
+      }
+    }
   }
   return result;
 }

src/component/scheduler.ts

@@ -25,12 +25,24 @@ export class Scheduler {
     this.requestAnimationFrame = requestAnimationFrame;
   }
 
-  addFiber(fiber, callback) {
-    this.tasks.push({ fiber, callback });
-    if (this.isRunning) {
-      return;
-    }
-    this.scheduleTasks();
+  addFiber(fiber): Promise<void> {
+    return new Promise((resolve, reject) => {
+      if (fiber.error) {
+        return reject(fiber.error);
+      }
+      this.tasks.push({
+        fiber,
+        callback: () => {
+          if (fiber.error) {
+            return reject(fiber.error);
+          }
+          resolve();
+        }
+      });
+      if (!this.isRunning) {
+        this.scheduleTasks();
+      }
+    });
   }
 
   /**
@@ -41,11 +53,19 @@ export class Scheduler {
     let tasks = this.tasks;
     this.tasks = [];
     tasks = tasks.filter(task => {
-      if (task.fiber.isCancelled) {
+      if (task.fiber.isCompleted) {
+        task.callback();
         return false;
       }
       if (task.fiber.counter === 0) {
-        task.callback(task.fiber.error);
+        if (!task.fiber.error) {
+          try {
+            task.fiber.complete();
+          } catch (e) {
+            task.fiber.handleError(e);
+          }
+        }
+        task.callback();
         return false;
       }
       return true;
@@ -65,3 +85,6 @@ export class Scheduler {
     });
   }
 }
+
+const raf = window.requestAnimationFrame.bind(window);
+export const scheduler = new Scheduler(raf);

src/config.ts

@@ -0,0 +1,30 @@
+import { QWeb } from "./qweb/index";
+
+/**
+ * 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 {
+  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/reference/config.md#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.`);
+    }
+  }
+});

src/context.ts

@@ -1,7 +1,8 @@
-import { Component, scheduler } from "./component/component";
+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,
@@ -12,6 +13,28 @@ import { onWillUnmount } from "./hooks";
  * 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;
@@ -22,40 +45,52 @@ export class Context extends EventBus {
   constructor(state: Object = {}) {
     super();
     this.observer = new Observer();
-    this.observer.notifyCB = this.__notifyComponents.bind(this);
+    this.observer.notifyCB = () => {
+      // notify components in the next microtask tick to ensure that subscribers
+      // are notified only once for all changes that occur in the same micro tick
+      let rev = this.rev;
+      return Promise.resolve().then(() => {
+        if (rev === this.rev) {
+          this.__notifyComponents();
+        }
+      });
+    };
     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.  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.
+   * 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 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.
+   * 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.
    *
-   * A potential cheap way to improve this situation is to keep track of the
-   * depth of a component in the component tree. A root component has a depth of
-   * 1, then its children of 2 and so on... Then, we can update all components
-   * with the same depth 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 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) {
-        const render = sub.callback.call(sub.owner, rev);
-        scheduler.flush();
-        await render;
-      }
+    const subscriptions = this.subscriptions.update;
+    const groups = partitionBy(subscriptions, s => (s.owner ? s.owner.__owl__.depth : -1));
+    for (let group of groups) {
+      const proms = group.map(sub => 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 Promise.all(proms);
     }
   }
 }
@@ -103,9 +138,11 @@ export function useContextWithCB(ctx: Context, component: Component<any, any>, m
       await method();
     }
   });
-  onWillUnmount(() => {
+  const __destroy = component.__destroy;
+  component.__destroy = (parent) => {
     ctx.off("update", component);
     delete mapping[id];
-  });
+    __destroy.call(component, parent);
+  }
   return ctx.state;
 }

src/core/observer.ts

@@ -24,14 +24,6 @@ export class Observer {
   weakMap: WeakMap<any, any> = new WeakMap();
 
   notifyCB() {}
-  async notifyChange() {
-    this.dirty = true;
-    await Promise.resolve();
-    if (this.dirty) {
-      this.dirty = false;
-      this.notifyCB();
-    }
-  }
 
   observe<T>(value: T, parent?: any): T {
     if (value === null || typeof value !== "object" || value instanceof Date) {
@@ -46,10 +38,6 @@ 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;
@@ -69,7 +57,7 @@ export class Observer {
           }
           self._updateRevNumber(target);
           target[key] = newVal;
-          self.notifyChange();
+          self.notifyCB();
         }
         return true;
       },
@@ -77,7 +65,7 @@ export class Observer {
         if (key in target) {
           delete target[key];
           self._updateRevNumber(target);
-          self.notifyChange();
+          self.notifyCB();
         }
         return true;
       }
@@ -87,7 +75,6 @@ export class Observer {
       value,
       proxy,
       rev: this.rev,
-      deepRev: this.rev,
       parent
     };
 
@@ -99,11 +86,10 @@ 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.deepRev++;
+      metadata.rev++;
     } while ((parent = metadata.parent) && parent !== target);
   }
 }

src/core/owl_event.ts

@@ -0,0 +1,15 @@
+import { Component } from "../component/component";
+
+/**
+ * We define here OwlEvent, a subclass of CustomEvent, with an additional
+ * attribute:
+ *  - originalComponent: the component that triggered the event
+ */
+
+export class OwlEvent<T> extends CustomEvent<T> {
+  originalComponent: Component<any, any>;
+  constructor(component, eventType, options) {
+    super(eventType, options);
+    this.originalComponent = component;
+  }
+}

src/hooks.ts

@@ -104,7 +104,12 @@ export function useRef(name: string): Ref {
   return {
     get el(): HTMLElement | null {
       const val = __owl__.refs && __owl__.refs[name];
-      return val instanceof HTMLElement ? val : null;
+      if (val instanceof HTMLElement) {
+        return val;
+      } else if (val instanceof Component) {
+        return val.el;
+      }
+      return null;
     },
     get comp(): Component<any, any> | null {
       const val = __owl__.refs && __owl__.refs[name];

src/index.ts

@@ -7,6 +7,7 @@
 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 * as _utils from "./utils";
 import * as _tags from "./tags";
@@ -19,6 +20,7 @@ import { Router } from "./router/router";
 
 export { Component } from "./component/component";
 export { QWeb };
+export { config };
 
 export const Context = _context.Context;
 export const useState = _hooks.useState;
@@ -35,20 +37,3 @@ export const hooks = Object.assign({}, _hooks, {
   useStore: _store.useStore
 });
 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.`);
-    }
-  }
-});

src/qweb/base_directives.ts

@@ -1,5 +1,4 @@
 import { CompilationContext } from "./compilation_context";
-import { QWebExprVar } from "./expression_parser";
 import { QWeb } from "./qweb";
 import { htmlToVDOM } from "../vdom/html_to_vdom";
 
@@ -34,7 +33,7 @@ function compileValueNode(value: any, node: Element, qweb: QWeb, ctx: Compilatio
     return;
   }
 
-  if (value.xml instanceof NodeList) {
+  if (value.xml instanceof NodeList && !value.id) {
     for (let node of Array.from(value.xml)) {
       qweb._compileNode(<ChildNode>node, ctx);
     }
@@ -71,6 +70,12 @@ function compileValueNode(value: any, node: Element, qweb: QWeb, ctx: Compilatio
     qweb._compileChildren(node, ctx);
   }
 
+  if (value.xml instanceof NodeList && value.id) {
+    ctx.addElse();
+    for (let node of Array.from(value.xml)) {
+      qweb._compileNode(<ChildNode>node, ctx);
+    }
+  }
   ctx.closeIf();
 }
 
@@ -104,22 +109,21 @@ QWeb.addDirective({
   atNodeEncounter({ node, ctx }): boolean {
     const variable = node.getAttribute("t-set")!;
     let value = node.getAttribute("t-value")!;
+    ctx.variables[variable] = ctx.variables[variable] || {};
+    let qwebvar = ctx.variables[variable];
+
     if (value) {
       const formattedValue = ctx.formatExpression(value);
-      if (ctx.variables.hasOwnProperty(variable)) {
-        ctx.addLine(`${(<QWebExprVar>ctx.variables[variable]).id} = ${formattedValue}`);
+      if (ctx.variables.hasOwnProperty(variable) && qwebvar.id) {
+        ctx.addLine(`${qwebvar.id} = ${formattedValue}`);
       } else {
         const varName = `_${ctx.generateID()}`;
         ctx.addLine(`var ${varName} = ${formattedValue};`);
-        ctx.variables[variable] = {
-          id: varName,
-          expr: formattedValue
-        };
+        qwebvar.id = varName;
+        qwebvar.expr = formattedValue;
       }
     } else {
-      ctx.variables[variable] = {
-        xml: node.childNodes
-      };
+      qwebvar.xml = node.childNodes;
     }
     return true;
   }
@@ -133,7 +137,7 @@ 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(typeof cond === "string" ? ctx.formatExpression(cond) : cond.id!);
     return false;
   },
   finalize({ ctx }) {
@@ -244,8 +248,8 @@ QWeb.addDirective({
       // add new variables, if any
       for (let key in tempCtx.variables) {
         const v = tempCtx.variables[key];
-        if ((<QWebExprVar>v).expr) {
-          ctx.addLine(`let ${(<QWebExprVar>v).id} = ${(<QWebExprVar>v).expr};`);
+        if (v.expr) {
+          ctx.addLine(`let ${v.id} = ${v.expr};`);
         }
         // todo: handle XML variables...
       }

src/qweb/compilation_context.ts

@@ -1,4 +1,4 @@
-import { compileExpr, QWebVar, QWebExprVar } from "./expression_parser";
+import { compileExpr, QWebVar } from "./expression_parser";
 
 export const INTERP_REGEXP = /\{\{.*?\}\}/g;
 //------------------------------------------------------------------------------
@@ -47,6 +47,30 @@ export class CompilationContext {
     return id;
   }
 
+  /**
+   * This method generates a "template key", which is basically a unique key
+   * which depends on the currently set keys, and on the iteration numbers (if
+   * we are in a loop).
+   *
+   * Such a key is necessary when we need to associate an id to some element
+   * generated by a template (for example, a component)
+   */
+  generateTemplateKey(): string {
+    const id = this.generateID();
+    let locationExpr = `\`__${this.generateID()}__`;
+    for (let i = 0; i < this.loopNumber - 1; i++) {
+      locationExpr += `\${i${i + 1}}__`;
+    }
+    if (this.lastNodeKey || this.currentKey) {
+      const k = this.lastNodeKey || this.currentKey;
+      this.addLine(`let k${id} = ${locationExpr}\` + ${k};`);
+    } else {
+      locationExpr += this.loopNumber ? `\${i${this.loopNumber}}__\`` : "`";
+      this.addLine(`let k${id} = ${locationExpr};`);
+    }
+    return `k${id}`;
+  }
+
   generateCode(): string[] {
     const shouldTrackScope = this.shouldTrackScope && this.scopeVars.length;
     if (shouldTrackScope) {
@@ -149,7 +173,7 @@ export class CompilationContext {
     this.addLine("}");
   }
 
-  getValue(val: any): QWebExprVar | string {
+  getValue(val: any): QWebVar | string {
     return val in this.variables ? this.getValue(this.variables[val]) : val;
   }
 

src/qweb/expression_parser.ts

@@ -25,7 +25,7 @@
 // Misc types, constants and helpers
 //------------------------------------------------------------------------------
 
-const RESERVED_WORDS = "true,false,NaN,null,undefined,debugger,console,window,in,instanceof,new,function,return,this,typeof,eval,void,Math,RegExp,Array,Object,Date".split(
+const RESERVED_WORDS = "true,false,NaN,null,undefined,debugger,console,window,in,instanceof,new,function,return,this,eval,void,Math,RegExp,Array,Object,Date".split(
   ","
 );
 
@@ -38,17 +38,12 @@ const WORD_REPLACEMENT = {
   lte: "<="
 };
 
-export interface QWebExprVar {
-  id: string;
-  expr: string;
+export interface QWebVar {
+  id?: string;
+  expr?: string;
+  xml?: NodeList;
 }
 
-export interface QWebXMLVar {
-  xml: NodeList;
-}
-
-export type QWebVar = QWebExprVar | QWebXMLVar;
-
 //------------------------------------------------------------------------------
 // Tokenizer
 //------------------------------------------------------------------------------
@@ -82,7 +77,9 @@ const STATIC_TOKEN_MAP: { [key: string]: TKind } = {
   ")": "RIGHT_PAREN"
 };
 
-const OPERATORS = ".,===,==,+,!==,!=,!,||,&&,>=,>,<=,<,?,-,*,/,%".split(",");
+// note that the space after typeof is relevant. It makes sure that the formatted
+// expression has a space after typeof
+const OPERATORS = ".,===,==,+,!==,!=,!,||,&&,>=,>,<=,<,?,-,*,/,%,typeof ".split(",");
 
 type Tokenizer = (expr: string) => Token | false;
 
@@ -165,9 +162,9 @@ const tokenizeOperator: Tokenizer = function(expr) {
 const TOKENIZERS = [
   tokenizeString,
   tokenizeNumber,
+  tokenizeOperator,
   tokenizeSymbol,
-  tokenizeStatic,
-  tokenizeOperator
+  tokenizeStatic
 ];
 
 /**
@@ -252,7 +249,7 @@ export function compileExpr(expr: string, vars: { [key: string]: QWebVar }): str
       }
       if (isVar) {
         if (token.value in vars && "id" in vars[token.value]) {
-          token.value = (<QWebExprVar>vars[token.value]).id;
+          token.value = vars[token.value].id!;
         } else {
           token.value = `context['${token.value}']`;
         }

src/qweb/extensions.ts

@@ -231,7 +231,17 @@ QWeb.addDirective({
     const type = node.getAttribute("type");
     let handler;
     let event = fullName.includes(".lazy") ? "change" : "input";
-    const expr = ctx.formatExpression(value);
+
+    // we keep here a reference to the "base expression" (if the expression
+    // is `t-model="some.expr.value", then the base expression is "some.expr").
+    // This is necessary so we can capture it in the handler closure.
+    let expr = ctx.formatExpression(value);
+    const index = expr.lastIndexOf(".");
+    const baseExpr = expr.slice(0, index);
+    ctx.addLine(`let expr${nodeID} = ${baseExpr};`);
+
+    expr = `expr${nodeID}.${expr.slice(index + 1)}`;
+    const key = ctx.generateTemplateKey();
     if (node.tagName === "select") {
       ctx.addLine(`p${nodeID}.props = {value: ${expr}};`);
       addNodeHook("create", `n.elm.value=${expr};`);
@@ -255,10 +265,8 @@ QWeb.addDirective({
       }
       handler = `(ev) => {${expr} = ${valueCode}}`;
     }
-    ctx.addLine(
-      `extra.handlers['${event}' + ${nodeID}] = extra.handlers['${event}' + ${nodeID}] || (${handler});`
-    );
-    ctx.addLine(`p${nodeID}.on['${event}'] = extra.handlers['${event}' + ${nodeID}];`);
+    ctx.addLine(`extra.handlers[${key}] = extra.handlers[${key}] || (${handler});`);
+    ctx.addLine(`p${nodeID}.on['${event}'] = extra.handlers[${key}];`);
   }
 });
 

src/qweb/qweb.ts

@@ -460,6 +460,8 @@ export class QWeb extends EventBus {
       // this is a component, we modify in place the xml document to change
       // <SomeComponent ... /> to <t t-component="SomeComponent" ... />
       node.setAttribute("t-component", node.tagName);
+    } else if (node.tagName !== 't' && node.hasAttribute('t-component')) {
+      throw new Error(`Directive 't-component' can only be used on <t> nodes (used on a <${node.tagName}>)`);
     }
     const attributes = (<Element>node).attributes;
 

src/store.ts

@@ -84,8 +84,11 @@ 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);
+  if (!(store instanceof Store)) {
+    throw new Error(`No store found when connecting '${component.constructor.name}'`);
+  }
   let result = selector(store.state, component.props);
-  const hashFn = store.observer.deepRevNumber.bind(store.observer);
+  const hashFn = store.observer.revNumber.bind(store.observer);
   let revNumber = hashFn(result) || result;
   const isEqual = options.isEqual || isStrictEqual;
   if (!store.updateFunctions[component.__owl__.id]) {
@@ -108,15 +111,14 @@ export function useStore(selector, options: SelectorOptions = {}): any {
 
   useContextWithCB(store, component, function(): Promise<void> | void {
     let shouldRender = false;
-    updateFunctions.forEach(function(updateFn) {
-      shouldRender = updateFn() || shouldRender;
-    });
+    for (let fn of updateFunctions) {
+      shouldRender = fn() || shouldRender;
+    }
     if (shouldRender) {
       return component.render();
     }
   });
   onWillUpdateProps(props => {
-    // FIXME: only do that if not keepalive + do it in destroy in that case
     delete store.updateFunctions[component.__owl__.id];
     result = selector(store.state, props);
   });

src/vdom/html_to_vdom.ts

@@ -20,10 +20,8 @@ function htmlToVNode(node: ChildNode): VNode {
     attrs[attr.name] = attr.textContent;
   }
   const children: VNode[] = [];
-  if (node.hasChildNodes) {
-    for (let c of node.childNodes) {
-      children.push(htmlToVNode(c));
-    }
+  for (let c of node.childNodes) {
+    children.push(htmlToVNode(c));
   }
   return h((node as Element).tagName, { attrs }, children);
 }

tests/__snapshots__/animations.test.ts.snap

@@ -12,8 +12,8 @@ exports[`animations t-transition combined with component 1`] = `
     let c1 = [], p1 = {key:1};
     var vn1 = h('div', p1, c1);
     //COMPONENT
-    let templateId3 = \`__4__\`;
-    let w3 = templateId3 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[templateId3]] : false;
+    let k4 = \`__5__\`;
+    let w3 = k4 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k4]] : false;
     let props3 = {};
     if (w3 && w3.__owl__.currentFiber && !w3.__owl__.vnode) {
         w3.destroy();
@@ -28,17 +28,18 @@ exports[`animations t-transition combined with component 1`] = `
         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;
+        parent.__owl__.cmap[k4] = 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 = () => {
+        let pvnode = h('dummy', {key: k4, 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();
         };
         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; });
+        def2.then(function () { if (fiber.isCompleted) { return; } const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
         c1.push(pvnode);
         w3.__owl__.pvnode = pvnode;
     }
+    w3.__owl__.parentLastFiberId = extra.fiber.id;
     sibling = w3.__owl__.currentFiber || sibling;
     return vn1;
 }"
@@ -57,8 +58,8 @@ exports[`animations t-transition combined with t-component and t-if 1`] = `
     var vn1 = h('div', p1, c1);
     if (context['state'].display) {
         //COMPONENT
-        let templateId3 = \`__4__\`;
-        let w3 = templateId3 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[templateId3]] : false;
+        let k4 = \`__5__\`;
+        let w3 = k4 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k4]] : false;
         let props3 = {};
         if (w3 && w3.__owl__.currentFiber && !w3.__owl__.vnode) {
             w3.destroy();
@@ -73,17 +74,18 @@ exports[`animations t-transition combined with t-component and t-if 1`] = `
             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;
+            parent.__owl__.cmap[k4] = 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 = () => {
+            let pvnode = h('dummy', {key: k4, 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();
         };
         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; });
+            def2.then(function () { if (fiber.isCompleted) { return; } const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
             c1.push(pvnode);
             w3.__owl__.pvnode = pvnode;
         }
+        w3.__owl__.parentLastFiberId = extra.fiber.id;
         sibling = w3.__owl__.currentFiber || sibling;
     }
     return vn1;

tests/animations.test.ts

@@ -29,6 +29,7 @@ let cssEl: HTMLElement;
 beforeEach(() => {
   fixture = makeTestFixture();
   env = makeTestEnv();
+  Component.env = env;
   qweb = new QWeb();
 });
 
@@ -108,7 +109,7 @@ describe("animations", () => {
     class TestWidget extends Widget {
       state = useState({ hide: false });
     }
-    const widget = new TestWidget(env);
+    const widget = new TestWidget();
 
     // insert widget into the DOM
     let def = makeDeferred();
@@ -151,7 +152,7 @@ describe("animations", () => {
       state = useState({ hide: false });
       span = useRef("span");
     }
-    const widget = new TestWidget(env);
+    const widget = new TestWidget();
 
     // insert widget into the DOM
     let def = makeDeferred();
@@ -180,7 +181,7 @@ describe("animations", () => {
     class Parent extends Widget {
       static components = { Child: Child };
     }
-    const widget = new Parent(env);
+    const widget = new Parent();
 
     let def = makeDeferred();
     var spanNode;
@@ -220,7 +221,7 @@ describe("animations", () => {
       static components = { Child: Child };
       state = useState({ display: true });
     }
-    const widget = new Parent(env);
+    const widget = new Parent();
 
     let def = makeDeferred();
     var spanNode;
@@ -251,11 +252,11 @@ 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="__5__">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="__5__">blue</span></div>'
       );
       def.resolve();
     });
@@ -283,7 +284,7 @@ describe("animations", () => {
       }
     }
 
-    const widget = new Parent(env);
+    const widget = new Parent();
     await widget.mount(fixture);
     let button = widget.el!.querySelector("button");
 
@@ -341,7 +342,7 @@ describe("animations", () => {
       }
     }
 
-    const widget = new Parent(env);
+    const widget = new Parent();
     await widget.mount(fixture);
     let button = widget.el!.querySelector("button");
 

tests/component/__snapshots__/props_validation.test.ts.snap

@@ -12,8 +12,8 @@ exports[`props validation props are validated in dev mode (code snapshot) 1`] =
     let c1 = [], p1 = {key:1};
     var vn1 = h('div', p1, c1);
     //COMPONENT
-    let templateId3 = \`__4__\`;
-    let w3 = templateId3 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[templateId3]] : false;
+    let k4 = \`__5__\`;
+    let w3 = k4 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k4]] : false;
     let props3 = {message:1};
     if (w3 && w3.__owl__.currentFiber && !w3.__owl__.vnode) {
         w3.destroy();
@@ -28,14 +28,15 @@ exports[`props validation props are validated in dev mode (code snapshot) 1`] =
         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;
+        parent.__owl__.cmap[k4] = 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();}}});
+        let pvnode = h('dummy', {key: k4, 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; });
+        def2.then(function () { if (fiber.isCompleted) { return; } const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
         c1.push(pvnode);
         w3.__owl__.pvnode = pvnode;
     }
+    w3.__owl__.parentLastFiberId = extra.fiber.id;
     sibling = w3.__owl__.currentFiber || sibling;
     return vn1;
 }"

tests/component/props_validation.test.ts

@@ -15,6 +15,7 @@ let dev: boolean = false;
 beforeEach(() => {
   fixture = makeTestFixture();
   env = makeTestEnv();
+  Component.env = env;
   dev = QWeb.dev;
   QWeb.dev = true;
 });
@@ -35,17 +36,32 @@ describe("props validation", () => {
       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;
-    expect(() => {
-      new TestWidget(env);
-    }).toThrow();
+    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;
 
     QWeb.dev = false;
-
-    expect(() => {
-      new TestWidget(env);
-    }).not.toThrow();
+    try {
+      const p = new Parent();
+      await p.mount(fixture);
+    } catch (e) {
+      error = e;
+    }
+    expect(error).toBeUndefined();
   });
 
   test("props: list of strings", async () => {
@@ -53,10 +69,20 @@ describe("props validation", () => {
       static props = ["message"];
       static template = xml`<div>hey</div>`;
     }
+    class Parent extends Widget {
+      static components = { TestWidget };
+      static template = xml`<div><TestWidget /></div>`;
+    }
 
-    expect(() => {
-      new TestWidget(env);
-    }).toThrow("Missing props 'message' (component 'TestWidget')");
+    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')`);
   });
 
   test("validate simple types", async () => {
@@ -69,23 +95,50 @@ 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 };
 
-      expect(() => {
-        new TestWidget(env);
-      }).toThrow("Missing props 'p'");
+      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, { p: test.ok });
-      }).not.toThrow();
+      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.ko });
-      }).toThrow("Props 'p' of invalid type in component");
+      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'`);
     }
   });
 
@@ -99,119 +152,306 @@ 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>`;
+      let TestWidget = class extends Component<any, any> {
         static props = { p: { type: test.type } };
+        static template = xml`<div>hey</div>`;
       };
+      Parent.components = { TestWidget };
 
-      expect(() => {
-        new TestWidget(env);
-      }).toThrow("Missing props 'p'");
+      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, { p: test.ok });
-      }).not.toThrow();
+      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.ko });
-      }).toThrow("Props 'p' of invalid type in component");
+      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'`);
     }
   });
 
   test("can validate a prop with multiple types", async () => {
-    let TestWidget = class extends Widget {
+    class TestWidget extends Component<any, any> {
       static template = xml`<div>hey</div>`;
       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;
+      }
+    }
 
-    expect(() => {
-      new TestWidget(env, { p: "string" });
-      new TestWidget(env, { p: true });
-    }).not.toThrow();
+    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: 1 });
-    }).toThrow("Props 'p' of invalid type in component");
+    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'");
   });
 
   test("can validate an optional props", async () => {
-    let TestWidget = class extends Widget {
+    class TestWidget extends Component<any, any> {
       static template = xml`<div>hey</div>`;
       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;
+      }
+    }
 
-    expect(() => {
-      new TestWidget(env, { p: "hey" });
-      new TestWidget(env, {});
-    }).not.toThrow();
+    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: 1 });
-    }).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'`);
   });
 
   test("can validate an array with given primitive type", async () => {
-    let TestWidget = class extends Widget {
+    class TestWidget extends Component<any, any> {
       static template = xml`<div>hey</div>`;
       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;
+      }
+    }
 
-    expect(() => {
-      new TestWidget(env, { p: [] });
-      new TestWidget(env, { p: ["string"] });
-    }).not.toThrow();
+    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: [1] });
-    }).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: ["string", 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;
+    }
   });
 
   test("can validate an array with multiple sub element types", async () => {
-    let TestWidget = class extends Widget {
+    class TestWidget extends Component<any, any> {
       static template = xml`<div>hey</div>`;
       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;
+      }
+    }
 
-    expect(() => {
-      new TestWidget(env, { p: [] });
-      new TestWidget(env, { p: ["string"] });
-      new TestWidget(env, { p: [false, true, "string"] });
-    }).not.toThrow();
+    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: [true, 1] });
-    }).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'`);
   });
 
   test("can validate an object with simple shape", async () => {
-    let TestWidget = class extends Widget {
+    class TestWidget extends Component<any, any> {
       static template = xml`<div>hey</div>`;
       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;
+      }
+    }
 
-    expect(() => {
-      new TestWidget(env, { p: { id: 1, url: "url" } });
-      new TestWidget(env, { p: { id: 1, url: "url", extra: true } });
-    }).not.toThrow();
+    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" } });
-    }).toThrow();
+    try {
+      props = { p: { id: 1, url: "url", extra: true } };
+      const p = new Parent();
+      await p.mount(fixture);
+    } catch (e) {
+      error = e;
+    }
+    expect(error).toBeDefined();
+    expect(error.message).toBe("Invalid prop 'p' in component TestWidget (unknown prop 'extra')");
 
-    expect(() => {
-      new TestWidget(env, { p: { id: 1 } });
-    }).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'`);
   });
 
   test("can validate recursively complicated prop def", async () => {
-    let TestWidget = class extends Widget {
+    class TestWidget extends Component<any, any> {
       static template = xml`<div>hey</div>`;
       static props = {
         p: {
@@ -222,16 +462,77 @@ 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;
+      }
+    }
 
-    expect(() => {
-      new TestWidget(env, { p: { id: 1, url: true } });
-      new TestWidget(env, { p: { id: 1, url: [12] } });
-    }).not.toThrow();
+    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: [12, true] } });
-    }).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'`);
+  });
+
+  test("can validate optional attributes in nested sub props", () => {
+    class TestComponent extends Component<any, any> {
+      static props = {
+        myprop: {
+          type: Array,
+          element: {
+            type: Object,
+            shape: {
+              num: { type: Number, optional: true }
+            }
+          }
+        }
+      };
+    }
+    let error;
+    try {
+      QWeb.utils.validateProps(TestComponent, { myprop: [{}] });
+    } catch (e) {
+      error = e;
+    }
+    expect(error).toBeUndefined();
+
+    try {
+      QWeb.utils.validateProps(TestComponent, { myprop: [{ a: 1 }] });
+    } catch (e) {
+      error = e;
+    }
+    expect(error).toBeDefined();
+    expect(error.message).toBe(
+      "Invalid prop 'myprop' in component TestComponent (unknown prop 'a')"
+    );
   });
 
   test("props are validated in dev mode (code snapshot)", async () => {
@@ -249,7 +550,7 @@ describe("props validation", () => {
     class App extends Widget {
       static components = { Child };
     }
-    const app = new App(env);
+    const app = new App();
     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
@@ -280,6 +581,32 @@ describe("props validation", () => {
     }).toThrow();
   });
 
+  test("props with type array, and no element", async () => {
+    class TestWidget extends Widget {
+      static props = { myprop: { type: Array } };
+    }
+
+    expect(() => {
+      QWeb.utils.validateProps(TestWidget, { myprop: [1] });
+    }).not.toThrow();
+    expect(() => {
+      QWeb.utils.validateProps(TestWidget, { myprop: 1 });
+    }).toThrow(`Props 'myprop' of invalid type in component 'TestWidget'`);
+  });
+
+  test("props with type object, and no shape", async () => {
+    class TestWidget extends Widget {
+      static props = { myprop: { type: Object } };
+    }
+
+    expect(() => {
+      QWeb.utils.validateProps(TestWidget, { myprop: { a: 3 } });
+    }).not.toThrow();
+    expect(() => {
+      QWeb.utils.validateProps(TestWidget, { myprop: false });
+    }).toThrow(`Props 'myprop' of invalid type in component 'TestWidget'`);
+  });
+
   test("props: extra props cause an error", async () => {
     class TestWidget extends Widget {
       static props = ["message"];
@@ -334,7 +661,7 @@ describe("props validation", () => {
       static components = { TestWidget };
     }
 
-    const w = new App(env, {});
+    const w = new App(undefined, {});
     let error;
     try {
       await w.mount(fixture);
@@ -354,7 +681,7 @@ describe("props validation", () => {
       async __updateProps() {
         try {
           await Component.prototype.__updateProps.apply(this, arguments);
-        } catch(e) {
+        } catch (e) {
           error = e;
         }
       }
@@ -365,7 +692,7 @@ describe("props validation", () => {
       state: any = useState({ p: 1 });
     }
 
-    const w = new Parent(env);
+    const w = new Parent();
     await w.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><div>1</div></div>");
 
@@ -387,7 +714,7 @@ describe("props validation", () => {
       state: any = useState({ p: 1 });
     }
 
-    const w = new Parent(env);
+    const w = new Parent();
     await w.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><div>1</div></div>");
 
@@ -399,13 +726,18 @@ describe("props validation", () => {
 
 describe("default props", () => {
   test("can set default values", async () => {
-    class TestWidget extends Widget {
+    class TestWidget extends Component<any, any> {
       static defaultProps = { p: 4 };
-      static template = xml`<div>hey</div>`;
+      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 TestWidget(env, {});
-    expect(w.props.p).toBe(4);
+    const w = new Parent();
+    await w.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div><div>4</div></div>");
   });
 
   test("default values are also set whenever component is updated", async () => {
@@ -419,7 +751,7 @@ describe("default props", () => {
       state: any = useState({ p: 1 });
     }
 
-    const w = new Parent(env);
+    const w = new Parent();
     await w.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><div>1</div></div>");
 
@@ -440,7 +772,7 @@ describe("default props", () => {
       static components = { TestWidget };
     }
 
-    const w = new App(env, {});
+    const w = new App(undefined, {});
     await w.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>heyhey</span></div>");
   });

tests/context.test.ts

@@ -1,5 +1,5 @@
 import { makeDeferred, makeTestEnv, makeTestFixture, nextTick } from "./helpers";
-import { Component, Env } from "../src/component/component";
+import { Component } from "../src/component/component";
 import { Context, useContext } from "../src/context";
 import { xml } from "../src/tags";
 import { useState } from "../src/hooks";
@@ -11,14 +11,13 @@ import { useState } from "../src/hooks";
 // 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.
-// - env: a WEnv, necessary to create new components
+// - a test env, necessary to create components, that is set as env
 
 let fixture: HTMLElement;
-let env: Env;
 
 beforeEach(() => {
   fixture = makeTestFixture();
-  env = makeTestEnv();
+  Component.env = makeTestEnv();
 });
 
 afterEach(() => {
@@ -37,7 +36,7 @@ describe("Context", () => {
       static template = xml`<div><t t-esc="contextObj.value"/></div>`;
       contextObj = useContext(testContext);
     }
-    const test = new Test(env);
+    const test = new Test();
     await test.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>123</div>");
   });
@@ -49,7 +48,7 @@ describe("Context", () => {
       static template = xml`<div><t t-esc="contextObj.value"/></div>`;
       contextObj = useContext(testContext);
     }
-    const test = new Test(env);
+    const test = new Test();
     await test.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>123</div>");
     test.contextObj.value = 321;
@@ -68,7 +67,7 @@ describe("Context", () => {
       static template = xml`<div><Child /><Child /></div>`;
       static components = { Child };
     }
-    const parent = new Parent(env);
+    const parent = new Parent();
     await parent.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>123</span><span>123</span></div>");
     testContext.state.value = 321;
@@ -76,6 +75,93 @@ describe("Context", () => {
     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 (mostly) 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();
+    // we need to wait for an extra tick because it could happen (even though it
+    // is rare) that the second batch of renderings is not done yet, because
+    // the initial promise has been given to the macrotask queue, so a small
+    // delay happens.
+    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[] = [];
@@ -93,7 +179,7 @@ describe("Context", () => {
       static template = xml`<div><Child /></div>`;
       static components = { Child };
     }
-    const parent = new Parent(env);
+    const parent = new Parent();
     await parent.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>12</span></div>");
     expect(steps).toEqual(["child"]);
@@ -124,7 +210,7 @@ describe("Context", () => {
         return super.__render(fiber);
       }
     }
-    const parent = new Parent(env);
+    const parent = new Parent();
     await parent.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>123</span>321</div>");
     expect(steps).toEqual(["parent", "child"]);
@@ -158,7 +244,7 @@ describe("Context", () => {
         return super.__render(fiber);
       }
     }
-    const parent = new Parent(env);
+    const parent = new Parent();
     await parent.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>123</span></div>");
     expect(steps).toEqual(["parent", "child"]);
@@ -174,6 +260,35 @@ describe("Context", () => {
     expect(testContext.subscriptions.update.length).toBe(0);
   });
 
+  test("destroyed component before being mounted is inactive", async () => {
+    const testContext = new Context({ a: 123 });
+
+    class Child extends Component<any, any> {
+      static template = xml`<span><t t-esc="contextObj.a"/></span>`;
+      contextObj = useContext(testContext);
+      willStart() {
+        return makeDeferred();
+      }
+    }
+    class Parent extends Component<any, any> {
+      static template = xml`<div><Child t-if="state.flag"/></div>`;
+      static components = { Child };
+      state = useState({ flag: true });
+    }
+
+    const parent = new Parent();
+    const prom = parent.mount(fixture);
+    await nextTick(); // wait for Child to be instantiated
+    expect(testContext.subscriptions.update.length).toBe(1);
+    parent.state.flag = false;
+    await prom;
+    expect(fixture.innerHTML).toBe("<div></div>");
+    // 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();
@@ -202,7 +317,7 @@ describe("Context", () => {
       context = useContext(testContext);
     }
 
-    const component = new ComponentA(env);
+    const component = new ComponentA();
     await component.mount(fixture);
 
     expect(fixture.innerHTML).toBe("<div><p><span>1a</span></p></div>");

tests/core/observer.test.ts

@@ -8,13 +8,11 @@ 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;
@@ -33,23 +31,19 @@ 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,
@@ -63,7 +57,6 @@ 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);
@@ -71,7 +64,6 @@ 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);
   });
@@ -82,14 +74,11 @@ 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.deepRevNumber(obj.arr)).toBe(2);
-    expect(observer.revNumber(obj)).toBe(1);
-    expect(observer.deepRevNumber(obj)).toBe(2);
+    expect(observer.revNumber(obj)).toBe(2);
     expect(observer.rev).toBe(2);
   });
 
@@ -98,24 +87,20 @@ 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);
   });
 
@@ -126,19 +111,16 @@ 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);
@@ -146,7 +128,6 @@ 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);
@@ -154,21 +135,18 @@ 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);
@@ -187,8 +165,7 @@ describe("observer", () => {
     arr[0].kriek = 6;
 
     expect(observer.rev).toBe(3);
-    expect(observer.revNumber(arr)).toBe(2);
-    expect(observer.deepRevNumber(arr)).toBe(3);
+    expect(observer.revNumber(arr)).toBe(3);
     expect(observer.revNumber(arr[0])).toBe(3);
   });
 
@@ -238,7 +215,6 @@ 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";
@@ -247,7 +223,6 @@ 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"]);
@@ -259,13 +234,11 @@ 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);
   });
 
@@ -280,7 +253,7 @@ describe("observer", () => {
 
     state.arr[0].something = 2;
     expect(observer.rev).toBe(2);
-    expect(observer.revNumber(state.arr)).toBe(1);
+    expect(observer.revNumber(state.arr)).toBe(2);
     expect(observer.revNumber(state.arr[0])).toBe(2);
   });
 
@@ -294,7 +267,7 @@ describe("observer", () => {
 
     state.a.b = 2;
     expect(observer.rev).toBe(2);
-    expect(observer.revNumber(state)).toBe(1);
+    expect(observer.revNumber(state)).toBe(2);
     expect(observer.revNumber(state.a)).toBe(2);
   });
 
@@ -312,7 +285,7 @@ describe("observer", () => {
     expect(observer.revNumber(obj.a)).toBe(2);
     obj.a.b = 3;
     expect(observer.rev).toBe(3);
-    expect(observer.revNumber(obj)).toBe(2);
+    expect(observer.revNumber(obj)).toBe(3);
     expect(observer.revNumber(obj.a)).toBe(3);
   });
 
@@ -320,22 +293,18 @@ 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(1);
-    expect(observer.deepRevNumber(state)).toBe(2);
+    expect(observer.revNumber(state)).toBe(2);
 
     state.arr.push(2);
     expect(observer.rev).toBe(3);
-    expect(observer.revNumber(state)).toBe(1);
-    expect(observer.deepRevNumber(state)).toBe(3);
+    expect(observer.revNumber(state)).toBe(3);
 
     state.n = 155;
     expect(observer.rev).toBe(4);
-    expect(observer.revNumber(state)).toBe(2);
-    expect(observer.deepRevNumber(state)).toBe(4);
+    expect(observer.revNumber(state)).toBe(4);
   });
 
   test("properly handle already observed state", () => {
@@ -361,18 +330,15 @@ 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);
   });
 
@@ -416,7 +382,7 @@ describe("observer", () => {
     expect(observer.revNumber(obj2)).toBe(1);
 
     obj2.key = 3;
-    expect(observer.revNumber(obj1)).toBe(1);
+    expect(observer.revNumber(obj1)).toBe(2);
     expect(observer.revNumber(obj2)).toBe(2);
   });
 
@@ -442,7 +408,7 @@ describe("observer", () => {
     obj.a = 111;
     obj.f = 222;
     await nextMicroTick();
-    expect(observer.notifyCB).toBeCalledTimes(4);
+    expect(observer.notifyCB).toBeCalledTimes(5);
   });
 
   test("throw error when state is mutated in object if allowMutation=false", async () => {

tests/doc_link_checker.test.ts

@@ -23,7 +23,7 @@ interface MarkDownSection {
 interface FileData {
   name: string;
   path: string[];
-  fullName: string
+  fullName: string;
   links: MarkDownLink[];
   sections: MarkDownSection[];
 }
@@ -31,30 +31,27 @@ interface FileData {
 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);
+  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.
@@ -74,7 +71,7 @@ function getFiles(path: string[] = []): FileData[] {
     if (f.isDirectory()) {
       return getFiles(path.concat(f.name));
     }
-    const fullName = path.join('/') + (path.length > 0 ? '/' : '') + f.name;
+    const fullName = path.join("/") + (path.length > 0 ? "/" : "") + f.name;
     return [
       {
         name: f.name,
@@ -88,62 +85,62 @@ function getFiles(path: string[] = []): FileData[] {
   return Array.prototype.concat(...files);
 }
 
-const LOCAL_FILES = ['LICENSE'];
+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)
+  // Step 1: extract path, name, hash
+  //      path = ['doc', 'architecture]
+  //      name = 'rendering.md'
+  //      hash = 'blabla' (or '' if no hash)
 
-    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);
-             }
-        }
-    } else {
-        // there are no file name, so this is a relative link to the current file
-        name = current.name;
-        path = current.path;
+  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);
+      }
     }
+  } 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)) {
-            return false;
-        }
-    }
+  // 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)) {
+      return false;
+    }
+  }
+
+  return true;
 }
 
 // adapted from https://medium.com/@mhagemann/the-ultimate-way-to-slugify-a-url-string-in-javascript-b8e4a0d849e1
@@ -164,25 +161,23 @@ function slugify(str) {
     .replace(/-+$/, ""); // Trim - from end of text
 }
 
-
-
 //--------------------------------------------------------------------------
 // Test
 //--------------------------------------------------------------------------
 
 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++;
-        }
+  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++;
+      }
     }
-    }
-    expect(invalidLinkNumber).toBe(0);
-    expect(linkNumber).toBeGreaterThan(10);
+  }
+  expect(invalidLinkNumber).toBe(0);
+  expect(linkNumber).toBeGreaterThan(10);
 });

tests/helpers.ts

@@ -1,4 +1,5 @@
-import { Env, scheduler } from "../src/component/component";
+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";

tests/hooks.test.ts

@@ -28,6 +28,7 @@ let env: Env;
 beforeEach(() => {
   fixture = makeTestFixture();
   env = makeTestEnv();
+  Component.env = env;
 });
 
 afterEach(() => {
@@ -44,7 +45,7 @@ describe("hooks", () => {
       static template = xml`<div><t t-esc="counter.value"/></div>`;
       counter = useState({ value: 42 });
     }
-    const counter = new Counter(env);
+    const counter = new Counter();
     await counter.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>42</div>");
     counter.counter.value = 3;
@@ -64,12 +65,12 @@ describe("hooks", () => {
     }
     class MyComponent extends Component<any, any> {
       static template = xml`<div>hey</div>`;
-      constructor(env) {
-        super(env);
+      constructor() {
+        super();
         useMyHook();
       }
     }
-    const component = new MyComponent(env);
+    const component = new MyComponent();
     await component.mount(fixture);
     expect(component).not.toHaveProperty("mounted");
     expect(component).not.toHaveProperty("willUnmount");
@@ -92,8 +93,8 @@ describe("hooks", () => {
     }
     class MyComponent extends Component<any, any> {
       static template = xml`<div>hey</div>`;
-      constructor(env) {
-        super(env);
+      constructor(parent, props) {
+        super(parent, props);
         useMyHook();
       }
     }
@@ -103,7 +104,7 @@ describe("hooks", () => {
       static components = { MyComponent };
       state = useState({ flag: true });
     }
-    const parent = new Parent(env);
+    const parent = new Parent();
     await parent.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><div>hey</div></div>");
     expect(steps).toEqual(["mounted"]);
@@ -126,8 +127,8 @@ describe("hooks", () => {
     }
     class MyComponent extends Component<any, any> {
       static template = xml`<div>hey</div>`;
-      constructor(env) {
-        super(env);
+      constructor() {
+        super();
         useMyHook();
       }
       mounted() {
@@ -137,7 +138,7 @@ describe("hooks", () => {
         steps.push("comp:willunmount");
       }
     }
-    const component = new MyComponent(env);
+    const component = new MyComponent();
     await component.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>hey</div>");
     component.unmount();
@@ -157,8 +158,8 @@ describe("hooks", () => {
     }
     class MyComponent extends Component<any, any> {
       static template = xml`<div>hey</div>`;
-      constructor(env) {
-        super(env);
+      constructor(parent, props) {
+        super(parent, props);
         useMyHook();
       }
       mounted() {
@@ -175,7 +176,7 @@ describe("hooks", () => {
       state = useState({ flag: true });
     }
 
-    const parent = new Parent(env);
+    const parent = new Parent();
     await parent.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><div>hey</div></div>");
     parent.state.flag = false;
@@ -197,13 +198,13 @@ describe("hooks", () => {
     }
     class MyComponent extends Component<any, any> {
       static template = xml`<div>hey</div>`;
-      constructor(env) {
-        super(env);
+      constructor() {
+        super();
         useMyHook(1);
         useMyHook(2);
       }
     }
-    const component = new MyComponent(env);
+    const component = new MyComponent();
     await component.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>hey</div>");
     component.unmount();
@@ -226,9 +227,12 @@ describe("hooks", () => {
         (this.button.el as HTMLButtonElement).innerHTML = String(this.value);
       }
     }
-    const counter = new Counter(env);
+    const counter = new Counter();
+    expect(counter.button.el).toBe(null);
     await counter.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><button>0</button></div>");
+    expect(counter.button.el).not.toBe(null);
+    expect(counter.button.el).toBe(fixture.querySelector("button"));
     counter.increment();
     await nextTick();
     expect(fixture.innerHTML).toBe("<div><button>1</button></div>");
@@ -247,7 +251,7 @@ describe("hooks", () => {
         expect(this.spanRef.el).toBeNull();
       }
     }
-    const component = new TestRef(env);
+    const component = new TestRef();
     await component.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>owl</span></div>");
     component.state.flag = false;
@@ -255,6 +259,104 @@ describe("hooks", () => {
     expect(fixture.innerHTML).toBe("<div></div>");
   });
 
+  test("t-refs on widget are components", async () => {
+    class WidgetB extends Component<any, any> {
+      static template = xml`<div>b</div>`;
+    }
+    class WidgetC extends Component<any, any> {
+      static template = xml`<div class="outer-div">Hello<WidgetB t-ref="mywidgetb" /></div>`;
+      static components = { WidgetB };
+      ref = useRef("mywidgetb");
+    }
+
+    const widget = new WidgetC();
+    expect(widget.ref.comp).toBe(null);
+    expect(widget.ref.el).toBe(null);
+    await widget.mount(fixture);
+    expect(widget.ref.comp).toBeInstanceOf(WidgetB);
+    expect(widget.ref.el).toEqual(fixture.querySelector(".outer-div > div"));
+  });
+
+  test("t-refs are bound at proper timing", async () => {
+    expect.assertions(2);
+    class Widget extends Component<any, any> {
+      static template = xml`<div>widget</div>`;
+    }
+
+    class ParentWidget extends Component<any, any> {
+      static template = xml`
+        <div>
+          <t t-foreach="state.list" t-as="elem" t-ref="child" t-key="elem" t-component="Widget"/>
+        </div>
+      `;
+      static components = { Widget };
+      state = useState({ list: <any>[] });
+      child = useRef("child");
+      willPatch() {
+        expect(this.child.comp).toBeNull();
+      }
+      patched() {
+        expect(this.child.comp).not.toBeNull();
+      }
+    }
+
+    const parent = new ParentWidget();
+    await parent.mount(fixture);
+    parent.state.list.push(1);
+    await nextTick();
+  });
+
+  test("t-refs are bound at proper timing (2)", async () => {
+    expect.assertions(10);
+    class Widget extends Component<any, any> {
+      static template = xml`<div>widget</div>`;
+    }
+    class ParentWidget extends Component<any, any> {
+      static template = xml`
+        <div>
+          <t t-if="state.child1" t-ref="child1" t-component="Widget"/>
+          <t t-if="state.child2" t-ref="child2" t-component="Widget"/>
+        </div>`;
+      static components = { Widget };
+      state = useState({ child1: true, child2: false });
+      child1 = useRef("child1");
+      child2 = useRef("child2");
+      count = 0;
+      mounted() {
+        expect(this.child1.comp).toBeDefined();
+        expect(this.child2.comp).toBeNull();
+      }
+      willPatch() {
+        if (this.count === 0) {
+          expect(this.child1.comp).toBeDefined();
+          expect(this.child2.comp).toBeNull();
+        }
+        if (this.count === 1) {
+          expect(this.child1.comp).toBeDefined();
+          expect(this.child2.comp).toBeDefined();
+        }
+      }
+      patched() {
+        if (this.count === 0) {
+          expect(this.child1.comp).toBeDefined();
+          expect(this.child2.comp).toBeDefined();
+        }
+        if (this.count === 1) {
+          expect(this.child1.comp).toBeNull();
+          expect(this.child2.comp).toBeDefined();
+        }
+        this.count++;
+      }
+    }
+
+    const parent = new ParentWidget();
+    await parent.mount(fixture);
+    parent.state.child2 = true;
+    await nextTick();
+    parent.state.child1 = false;
+    await nextTick();
+  });
+
   test("can use onPatched, onWillPatch", async () => {
     const steps: string[] = [];
     function useMyHook() {
@@ -270,13 +372,13 @@ describe("hooks", () => {
       static template = xml`<div><t t-if="state.flag">hey</t></div>`;
       state = useState({ flag: true });
 
-      constructor(env) {
-        super(env);
+      constructor() {
+        super();
         useMyHook();
       }
     }
 
-    const component = new MyComponent(env);
+    const component = new MyComponent();
     await component.mount(fixture);
     expect(component).not.toHaveProperty("patched");
     expect(component).not.toHaveProperty("willPatch");
@@ -304,8 +406,8 @@ describe("hooks", () => {
       static template = xml`<div><t t-if="state.flag">hey</t></div>`;
       state = useState({ flag: true });
 
-      constructor(env) {
-        super(env);
+      constructor() {
+        super();
         useMyHook();
       }
       willPatch() {
@@ -315,7 +417,7 @@ describe("hooks", () => {
         steps.push("comp:patched");
       }
     }
-    const component = new MyComponent(env);
+    const component = new MyComponent();
     await component.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>hey</div>");
     component.state.flag = false;
@@ -337,13 +439,13 @@ describe("hooks", () => {
     class MyComponent extends Component<any, any> {
       static template = xml`<div>hey<t t-esc="state.value"/></div>`;
       state = useState({ value: 1 });
-      constructor(env) {
-        super(env);
+      constructor() {
+        super();
         useMyHook(1);
         useMyHook(2);
       }
     }
-    const component = new MyComponent(env);
+    const component = new MyComponent();
     await component.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>hey1</div>");
     component.state.value++;
@@ -377,13 +479,13 @@ describe("hooks", () => {
                 <input t-ref="input2"/>
             </div>`;
 
-        constructor(env) {
-          super(env);
+        constructor() {
+          super();
           useAutofocus("input2");
         }
       }
 
-      const component = new SomeComponent(env);
+      const component = new SomeComponent();
       await component.mount(fixture);
       expect(fixture.innerHTML).toBe("<div><input><input></div>");
       const input2 = fixture.querySelectorAll("input")[1];
@@ -399,13 +501,13 @@ describe("hooks", () => {
             </div>`;
 
         state = useState({ flag: false });
-        constructor(env) {
-          super(env);
+        constructor() {
+          super();
           useAutofocus("input2");
         }
       }
 
-      const component = new SomeComponent(env);
+      const component = new SomeComponent();
       await component.mount(fixture);
       expect(fixture.innerHTML).toBe("<div><input></div>");
       expect(document.activeElement).toBe(document.body);
@@ -420,12 +522,12 @@ 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(env) {
-        super(env);
+      constructor() {
+        super();
         useSubEnv({ val: 3 });
       }
     }
-    const component = new TestComponent(env);
+    const component = new TestComponent();
     await component.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>3</div>");
     expect(env).not.toHaveProperty("val");
@@ -435,8 +537,8 @@ 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(env) {
-        super(env);
+      constructor(parent, props) {
+        super(parent, props);
         useSubEnv({ val: 5 });
       }
     }
@@ -444,12 +546,12 @@ describe("hooks", () => {
     class Parent extends Component<any, any> {
       static template = xml`<div><t t-esc="env.val"/><Child/></div>`;
       static components = { Child };
-      constructor(env) {
-        super(env);
+      constructor() {
+        super();
         useSubEnv({ val: 3 });
       }
     }
-    const component = new Parent(env);
+    const component = new Parent();
     await component.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>3<div>5</div></div>");
   });
@@ -478,7 +580,7 @@ describe("hooks", () => {
       state = useState({ value: 1 });
     }
 
-    const app = new App(env);
+    const app = new App();
     await app.mount(fixture);
     expect(app).not.toHaveProperty("willStart");
     expect(app).not.toHaveProperty("willUpdateProps");

tests/misc/async_root.test.ts

@@ -2,7 +2,7 @@ import { AsyncRoot } from "../../src/misc/async_root";
 import { useState } from "../../src/hooks";
 import { xml } from "../../src/tags";
 import { makeDeferred, makeTestFixture, makeTestEnv, nextTick } from "../helpers";
-import { Env, Component } from "../../src/component/component";
+import { Component } from "../../src/component/component";
 
 //------------------------------------------------------------------------------
 // Setup and helpers
@@ -11,14 +11,13 @@ import { Env, Component } from "../../src/component/component";
 // 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.
-// - env: a WEnv, necessary to create new components
+// - a test env, necessary to create components, that is set as env
 
 let fixture: HTMLElement;
-let env: Env;
 
 beforeEach(() => {
   fixture = makeTestFixture();
-  env = makeTestEnv();
+  Component.env = makeTestEnv();
 });
 
 afterEach(() => {
@@ -55,7 +54,7 @@ describe("Asyncroot", () => {
       }
     }
 
-    const parent = new Parent(env);
+    const parent = new Parent();
     await parent.mount(fixture);
 
     expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>0</span><span>0</span>");
@@ -103,7 +102,7 @@ describe("Asyncroot", () => {
       }
     }
 
-    const parent = new Parent(env);
+    const parent = new Parent();
     await parent.mount(fixture);
 
     expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>0</span><span>0</span>");
@@ -158,7 +157,7 @@ describe("Asyncroot", () => {
       }
     }
 
-    const parent = new Parent(env);
+    const parent = new Parent();
     await parent.mount(fixture);
 
     expect(fixture.querySelector(".children")!.innerHTML).toBe("<span>0/0</span><span>0/0</span>");

tests/qweb/__snapshots__/qweb.test.ts.snap

@@ -699,25 +699,25 @@ exports[`misc global 1`] = `
             } else {
                 c17.push({text: \`foo default\`});
             }
-            var _19 = 'bbb';
-            let c20 = [], p20 = {key:20};
-            var vn20 = h('span', p20, c20);
-            c14.push(vn20);
-            if (_19 || _19 === 0) {
-                c20.push({text: _19});
+            _11 = 'bbb'
+            let c19 = [], p19 = {key:19};
+            var vn19 = h('span', p19, c19);
+            c14.push(vn19);
+            if (_11 || _11 === 0) {
+                c19.push({text: _11});
             } else {
-                c20.push({text: \`foo default\`});
+                c19.push({text: \`foo default\`});
             }
         }
     }
-    let c21 = [], p21 = {key:21};
-    var vn21 = h('div', p21, c21);
-    c1.push(vn21);
-    var _22 = context['toto'];
-    if (_22 || _22 === 0) {
-        c21.push(...utils.htmlToVDOM(_22));
+    let c20 = [], p20 = {key:20};
+    var vn20 = h('div', p20, c20);
+    c1.push(vn20);
+    var _21 = context['toto'];
+    if (_21 || _21 === 0) {
+        c20.push(...utils.htmlToVDOM(_21));
     } else {
-        c21.push({text: \`toto default\`});
+        c20.push({text: \`toto default\`});
     }
     return vn1;
 }"
@@ -2400,6 +2400,90 @@ exports[`t-set t-set should reuse variable if possible 1`] = `
 }"
 `;
 
+exports[`t-set t-set, t-if, and mix of expression/body lookup, 1 1`] = `
+"function anonymous(context,extra
+) {
+    let sibling = null;
+    var h = this.h;
+    let c1 = [], p1 = {key:1};
+    var vn1 = h('div', p1, c1);
+    if (context['flag']) {
+    }
+    else {
+        var _2 = 0;
+    }
+    if (_2 || _2 === 0) {
+        c1.push({text: _2});
+    } else {
+        c1.push({text: \`1\`});
+    }
+    return vn1;
+}"
+`;
+
+exports[`t-set t-set, t-if, and mix of expression/body lookup, 1 2`] = `
+"function anonymous(context,extra
+) {
+    let sibling = null;
+    var h = this.h;
+    let c1 = [], p1 = {key:1};
+    var vn1 = h('div', p1, c1);
+    if (context['flag']) {
+    }
+    else {
+        var _2 = 0;
+    }
+    if (_2 || _2 === 0) {
+        c1.push({text: _2});
+    } else {
+        c1.push({text: \`1\`});
+    }
+    return vn1;
+}"
+`;
+
+exports[`t-set t-set, t-if, and mix of expression/body lookup, 2 1`] = `
+"function anonymous(context,extra
+) {
+    let sibling = null;
+    var h = this.h;
+    let c1 = [], p1 = {key:1};
+    var vn1 = h('div', p1, c1);
+    if (context['flag']) {
+        var _2 = 1;
+    }
+    else {
+    }
+    if (_2 || _2 === 0) {
+        c1.push({text: _2});
+    } else {
+        c1.push({text: \`0\`});
+    }
+    return vn1;
+}"
+`;
+
+exports[`t-set t-set, t-if, and mix of expression/body lookup, 2 2`] = `
+"function anonymous(context,extra
+) {
+    let sibling = null;
+    var h = this.h;
+    let c1 = [], p1 = {key:1};
+    var vn1 = h('div', p1, c1);
+    if (context['flag']) {
+        var _2 = 1;
+    }
+    else {
+    }
+    if (_2 || _2 === 0) {
+        c1.push({text: _2});
+    } else {
+        c1.push({text: \`0\`});
+    }
+    return vn1;
+}"
+`;
+
 exports[`t-set value priority 1`] = `
 "function anonymous(context,extra
 ) {

tests/qweb/qweb.test.ts

@@ -242,6 +242,32 @@ describe("t-set", () => {
     );
     expect(renderToString(qweb, "test", { somevariable: 43 })).toBe("<div>45</div>");
   });
+
+  test("t-set, t-if, and mix of expression/body lookup, 1", () => {
+    qweb.addTemplate(
+      "test",
+      `<div>
+        <t t-if="flag" t-set="ourvar">1</t>
+        <t t-else="" t-set="ourvar" t-value="0"></t>
+        <t t-esc="ourvar"/>
+      </div>`
+    );
+    expect(renderToString(qweb, "test", { flag: true })).toBe("<div>1</div>");
+    expect(renderToString(qweb, "test", { flag: false })).toBe("<div>0</div>");
+  });
+
+  test("t-set, t-if, and mix of expression/body lookup, 2", () => {
+    qweb.addTemplate(
+      "test",
+      `<div>
+        <t t-if="flag" t-set="ourvar" t-value="1"></t>
+        <t t-else="" t-set="ourvar">0</t>
+        <t t-esc="ourvar"/>
+      </div>`
+    );
+    expect(renderToString(qweb, "test", { flag: true })).toBe("<div>1</div>");
+    expect(renderToString(qweb, "test", { flag: false })).toBe("<div>0</div>");
+  });
 });
 
 describe("t-if", () => {

tests/qweb/qweb_expressions.test.ts

@@ -43,6 +43,10 @@ describe("tokenizer", () => {
       { type: "OPERATOR", value: "!==" },
       { type: "OPERATOR", value: "!=" }
     ]);
+    expect(tokenize("typeof a")).toEqual([
+      { type: "OPERATOR", value: "typeof " },
+      { type: "SYMBOL", value: "a" }
+    ]);
   });
 
   test("strings", () => {
@@ -112,6 +116,7 @@ describe("expression evaluation", () => {
     expect(compileExpr("!flag", {})).toBe("!context['flag']");
     expect(compileExpr("-3", {})).toBe("-3");
     expect(compileExpr("-a", {})).toBe("-context['a']");
+    expect(compileExpr("typeof a", {})).toBe("typeof context['a']");
   });
 
   test("various binary operators", () => {

tests/router/__snapshots__/route_component.test.ts.snap

@@ -13,10 +13,10 @@ exports[`RouteComponent can render simple cases 1`] = `
     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 k4 = \`__5__\` + nodeKey1;
+        let w3 = k4 in parent.__owl__.cmap ? parent.__owl__.children[parent.__owl__.cmap[k4]] : false;
+        let vn6 = {};
+        result = vn6;
         let props3 = Object.assign({}, context['env'].router.currentParams);
         if (w3 && w3.__owl__.currentFiber && !w3.__owl__.vnode) {
             w3.destroy();
@@ -25,20 +25,21 @@ exports[`RouteComponent can render simple cases 1`] = `
         if (w3) {
             w3.__updateProps(props3, extra.fiber, undefined, undefined, sibling);
             let pvnode = w3.__owl__.pvnode;
-            utils.defineProxy(vn5, pvnode);
+            utils.defineProxy(vn6, 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;
+            parent.__owl__.cmap[k4] = 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();}}});
+            let pvnode = h('dummy', {key: k4, 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);
+            def2.then(function () { if (fiber.isCompleted) { return; } const vnode = fiber.vnode; pvnode.sel = vnode.sel; });
+            utils.defineProxy(vn6, pvnode);
             w3.__owl__.pvnode = pvnode;
         }
+        w3.__owl__.parentLastFiberId = extra.fiber.id;
         sibling = w3.__owl__.currentFiber || sibling;
     }
     return result;

tests/router/link.test.ts

@@ -12,6 +12,7 @@ describe("Link component", () => {
   beforeEach(() => {
     fixture = makeTestFixture();
     env = <RouterEnv>makeTestEnv();
+    Component.env = env;
   });
 
   afterEach(() => {
@@ -38,7 +39,7 @@ describe("Link component", () => {
 
     router = new TestRouter(env, routes, { mode: "history" });
     router.navigate({ to: "users" });
-    const app = new App(env);
+    const app = new App();
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe('<div><a href="/about">About</a></div>');
 
@@ -69,7 +70,7 @@ describe("Link component", () => {
 
     router = new TestRouter(env, routes, { mode: "history" });
     router.navigate({ to: "users" });
-    const app = new App(env);
+    const app = new App();
     await app.mount(fixture);
 
     expect(window.location.pathname).toBe("/users");

tests/router/route_component.test.ts

@@ -12,6 +12,7 @@ describe("RouteComponent", () => {
   beforeEach(() => {
     fixture = makeTestFixture();
     env = <RouterEnv>makeTestEnv();
+    Component.env = env;
   });
 
   afterEach(() => {
@@ -45,7 +46,7 @@ describe("RouteComponent", () => {
 
     router = new TestRouter(env, routes, { mode: "history" });
     await router.navigate({ to: "about" });
-    const app = new App(env);
+    const app = new App();
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>About</span></div>");
 
@@ -72,7 +73,7 @@ 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(env);
+    const app = new App();
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>Book 1984</span></div>");
   });
@@ -98,7 +99,7 @@ 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(env);
+    const app = new App();
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>Book 1984|124</span></div>");
   });

tests/router/router.test.ts

@@ -54,13 +54,12 @@ describe("router miscellaneous", () => {
   });
 
   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');
+    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", () => {

tests/store_hooks.test.ts

@@ -12,6 +12,7 @@ describe("connecting a component to store", () => {
   beforeEach(() => {
     fixture = makeTestFixture();
     env = makeTestEnv();
+    Component.env = env;
   });
 
   afterEach(() => {
@@ -37,7 +38,7 @@ describe("connecting a component to store", () => {
     }
 
     (<any>env).store = store;
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div></div>");
@@ -47,6 +48,22 @@ describe("connecting a component to store", () => {
     expect(fixture.innerHTML).toBe("<div><span>hello</span></div>");
   });
 
+  test("throw error if no store is found", async () => {
+    class App extends Component<any, any> {
+      static template = xml`<div></div>`;
+      todos = useStore(state => state.todos);
+    }
+
+    let error;
+    try {
+      new App();
+    } catch (e) {
+      error = e;
+    }
+    expect(error).toBeDefined();
+    expect(error.message).toBe("No store found when connecting 'App'");
+  });
+
   test("can use useStore twice in a component", async () => {
     const state = { a: 1, b: 2 };
     const actions = {
@@ -69,7 +86,7 @@ describe("connecting a component to store", () => {
     App.prototype.__render = jest.fn(App.prototype.__render);
 
     (<any>env).store = store;
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>1</span><span>2</span></div>");
@@ -101,7 +118,7 @@ describe("connecting a component to store", () => {
     App.prototype.__render = jest.fn(App.prototype.__render);
 
     (<any>env).store = store;
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div></div>");
@@ -134,7 +151,7 @@ describe("connecting a component to store", () => {
     }
 
     (<any>env).store = store;
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>0</div>");
@@ -163,7 +180,7 @@ describe("connecting a component to store", () => {
     App.prototype.__render = jest.fn(App.prototype.__render);
 
     (<any>env).store = store;
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>0</div>");
@@ -198,7 +215,7 @@ describe("connecting a component to store", () => {
       todos = useStore(state => state.todos, { store });
     }
 
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div></div>");
@@ -228,7 +245,7 @@ describe("connecting a component to store", () => {
       storeState = useStore(state => state);
       dispatch = useDispatch();
     }
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><button>Inc</button><span>1</span></div>");
@@ -257,7 +274,7 @@ describe("connecting a component to store", () => {
     }
 
     (<any>env).store = store;
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>jupiler</span></div>");
@@ -294,7 +311,7 @@ describe("connecting a component to store", () => {
     }
 
     (<any>env).store = store;
-    const app = new TodoList(env);
+    const app = new TodoList();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>jupiler</span></div>");
@@ -347,7 +364,7 @@ describe("connecting a component to store", () => {
     }
 
     (<any>env).store = store;
-    const app = new TodoList(env);
+    const app = new TodoList();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe(
@@ -370,7 +387,7 @@ describe("connecting a component to store", () => {
     const state = { beers: { 1: { name: "jupiler" }, 2: { name: "kwak" } } };
     const store = new Store({ state });
     (<any>env).store = store;
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>jupiler</span></div>");
@@ -401,7 +418,7 @@ describe("connecting a component to store", () => {
     const store = new Store({ state, actions });
     (<any>env).store = store;
 
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>jupiler</span></div>");
@@ -446,7 +463,7 @@ describe("connecting a component to store", () => {
     };
     const store = new Store({ state, actions });
     (<any>env).store = store;
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><div><span>taster:aaron</span></div></div>");
@@ -513,7 +530,7 @@ describe("connecting a component to store", () => {
     };
     const store = new Store({ state, actions });
     (<any>env).store = store;
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><div><span>taster:aaron</span></div></div>");
@@ -555,6 +572,31 @@ describe("connecting a component to store", () => {
     );
   });
 
+  test("store changes occuring when mounting a component are notified", async () => {
+    const initialState = { x: { val: 1 } };
+    const actions = {
+      setValue({ state }, val) {
+        state.x.val = val;
+      }
+    };
+    class Parent extends Component<any, any> {
+      static template = xml`<div><t t-esc="x.val"/></div>`;
+      x = useStore(state => {
+        return Object.assign({}, state.x);
+      });
+      dispatch = useDispatch();
+    }
+    Parent.prototype.__render = jest.fn(Parent.prototype.__render);
+    Parent.env.store = new Store({ state: initialState, actions });
+
+    const parent = new Parent();
+    const prom = parent.mount(fixture);
+    parent.dispatch("setValue", 2);
+    await prom;
+    expect(fixture.innerHTML).toBe("<div>2</div>");
+    expect(Parent.prototype.__render).toHaveBeenCalledTimes(1);
+  });
+
   test("correct update order when parent/children are connected", async () => {
     const steps: string[] = [];
 
@@ -588,7 +630,7 @@ describe("connecting a component to store", () => {
 
     const store = new Store({ state, actions });
     (<any>env).store = store;
-    const app = new Parent(env);
+    const app = new Parent();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>a</span></div>");
@@ -639,7 +681,7 @@ describe("connecting a component to store", () => {
 
     const store = new Store({ state, actions });
     (<any>env).store = store;
-    const app = new Parent(env);
+    const app = new Parent();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>abc</span></div>");
@@ -713,7 +755,7 @@ describe("connecting a component to store", () => {
     }
 
     (<any>env).store = store;
-    const app = new TodoApp(env);
+    const app = new TodoApp();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe(
@@ -787,7 +829,7 @@ describe("connecting a component to store", () => {
     }
 
     (<any>env).store = store;
-    const app = new TodoApp(env);
+    const app = new TodoApp();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe(
@@ -833,7 +875,7 @@ describe("connecting a component to store", () => {
 
     const store = new Store({ state, actions });
     (<any>env).store = store;
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>a</div>");
@@ -870,7 +912,7 @@ describe("connecting a component to store", () => {
     }
     const store = new TestStore({ state: { val: 1 } });
     (<any>env).store = store;
-    const parent = new Parent(env);
+    const parent = new Parent();
 
     await parent.mount(fixture);
     expect(steps).toEqual(["on:update"]);
@@ -882,6 +924,46 @@ describe("connecting a component to store", () => {
     expect(steps).toEqual(["on:update", "off:update"]);
   });
 
+  test("connected child component destroyed by dispatched action", async () => {
+    let steps: any = [];
+
+    class Child extends Component<any, any> {
+      static template = xml`<div><t t-esc="store.val"/></div>`;
+      store = useStore(s => {
+        steps.push("child selector");
+        return s;
+      });
+    }
+    class Parent extends Component<any, any> {
+      static template = xml`<div><Child t-if="store.child" /></div>`;
+      static components = { Child };
+      store = useStore(s => {
+        steps.push("parent selector");
+        return s;
+      });
+      dispatch = useDispatch();
+    }
+
+    const state = { child: true, val: 1 };
+    const actions = {
+      toggleChild({ state }) {
+        state.child = !state.child;
+      }
+    };
+    const store = new Store({ state, actions });
+    (<any>env).store = store;
+    const parent = new Parent();
+
+    await parent.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div><div>1</div></div>");
+    expect(steps).toEqual(["parent selector", "child selector"]);
+
+    parent.dispatch("toggleChild");
+    await nextTick();
+    expect(fixture.innerHTML).toBe("<div></div>");
+    expect(steps).toEqual(["parent selector", "child selector", "parent selector"]);
+  });
+
   test("dispatch an action", async () => {
     class App extends Component<any, any> {
       static template = xml`<div><t t-esc="store.counter"/></div>`;
@@ -901,7 +983,7 @@ describe("connecting a component to store", () => {
 
     const store = new Store({ state, actions });
     (<any>env).store = store;
-    const app = new App(env);
+    const app = new App();
 
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div>0</div>");
@@ -920,6 +1002,7 @@ describe("various scenarios", () => {
   beforeEach(() => {
     fixture = makeTestFixture();
     env = makeTestEnv();
+    Component.env = env;
   });
 
   afterEach(() => {
@@ -978,7 +1061,8 @@ describe("various scenarios", () => {
     }
 
     (<any>env).store = store;
-    const message = new Message(env);
+    const message = new Message();
+
     await message.mount(fixture);
 
     expect(fixture.innerHTML).toMatchSnapshot();

tools/benchmarks/owl-0.21.0/app.js

@@ -15,8 +15,6 @@ class Counter extends owl.Component {
 // Message Widget
 //------------------------------------------------------------------------------
 class Message extends owl.Component {
-  static components = { Counter };
-
   shouldUpdate(nextProps) {
     return nextProps.message !== this.props.message;
   }
@@ -26,12 +24,11 @@ class Message extends owl.Component {
     });
   }
 }
-
+Message.components = { Counter };
 //------------------------------------------------------------------------------
 // Root Widget
 //------------------------------------------------------------------------------
 class App extends owl.Component {
-  static components = { Message };
   state = { messages: [], multipleFlag: false, clearAfterFlag: false };
 
   mounted() {
@@ -137,6 +134,7 @@ class App extends owl.Component {
     this.refs.log.innerHTML = "";
   }
 }
+App.components = { Message };
 
 //------------------------------------------------------------------------------
 // Application initialization

tools/benchmarks/owl-0.24.0/index.html

@@ -4,7 +4,7 @@
   <meta charset="UTF-8">
   <title>OWL v0.24.0 Benchmark</title>
   <link href="../shared/main.css" rel="stylesheet"/>
-  <script src='../../owl.js'></script>
+  <script src='owl.js'></script>
 </head>
 <body>
   <script src='app.js' type="module"></script>

tools/benchmarks/owl-master/app.js

@@ -16,8 +16,6 @@ class Counter extends owl.Component {
 // Message Widget
 //------------------------------------------------------------------------------
 class Message extends owl.Component {
-  static components = { Counter };
-
   shouldUpdate(nextProps) {
     return nextProps.message !== this.props.message;
   }
@@ -27,12 +25,12 @@ class Message extends owl.Component {
     });
   }
 }
+Message.components = { Counter };
 
 //------------------------------------------------------------------------------
 // Root Widget
 //------------------------------------------------------------------------------
 class App extends owl.Component {
-  static components = { Message };
   state = useState({ messages: [], multipleFlag: false, clearAfterFlag: false });
   logRef = useRef("log");
 
@@ -139,16 +137,17 @@ class App extends owl.Component {
     this.logRef.el.innerHTML = "";
   }
 }
+App.components = { Message };
 
 //------------------------------------------------------------------------------
 // Application initialization
 //------------------------------------------------------------------------------
 async function start() {
   const templates = await owl.utils.loadFile("templates.xml");
-  const env = {
+  App.env = {
     qweb: new owl.QWeb({ templates })
   };
-  const app = new App(env);
+  const app = new App();
   app.mount(document.body);
 }
 

tools/playground/app.js

@@ -70,13 +70,9 @@ if __name__ == "__main__":
 /**
  * Make an iframe, with all the js, css and xml properly injected.
  */
-function makeCodeIframe(js, css, xml, errorHandler) {
-  // check templates
-  var qweb = new owl.QWeb();
+function makeCodeIframe(js, css, xml) {
   const sanitizedXML = xml.replace(/<!--[\s\S]*?-->/g, "");
 
-  // will throw error if there is something wrong with xml
-  qweb.addTemplates(sanitizedXML);
 
   // create iframe
   const iframe = document.createElement("iframe");
@@ -90,16 +86,15 @@ function makeCodeIframe(js, css, xml, errorHandler) {
     owlScript.addEventListener("load", () => {
       const script = doc.createElement("script");
       script.type = "text/javascript";
-      const content = `owl.__info__.mode = 'dev';\nwindow.TEMPLATES = \`${sanitizedXML}\`;\n${js}`;
-      script.innerHTML = content;
-      iframe.contentWindow.addEventListener("error", errorHandler);
-      iframe.contentWindow.addEventListener("unhandledrejection", errorHandler);
-      setTimeout(function() {
-        if (iframe.contentWindow) {
-          iframe.contentWindow.removeEventListener("error", errorHandler);
-          iframe.contentWindow.removeEventListener("unhandledrejection", errorHandler);
+      const content = `
+        {
+          owl.config.mode = 'dev';
+          let templates = \`${sanitizedXML}\`;
+          const qweb = new owl.QWeb({ templates });
+          owl.Component.env = { qweb };
         }
-      }, 200);
+        ${js}`;
+      script.innerHTML = content;
       doc.body.appendChild(script);
     });
     doc.head.appendChild(owlScript);
@@ -125,20 +120,34 @@ async function makeApp(js, css, xml) {
     .join("\n");
 
   const JS = `
-async function loadTemplates() {
-  try {
-    return owl.utils.loadFile('app.xml');
-  } catch(e) {
-    console.error(\`This app requires a static server.  If you have python installed, try 'python app.py'\`);
-  }
-}
-
-function start([TEMPLATES]) {
-  // Application code
+/**
+ * This is the javascript code defined in the playground.
+ * In a larger application, this code should probably be moved in different
+ * sub files.
+ */
+function app() {
 ${processedJS}
 }
 
-Promise.all([loadTemplates(), owl.utils.whenReady()]).then(start);
+/**
+ * Initialization code
+ * This code load templates, and make sure everything is properly connected.
+ */
+async function start() {
+  let templates;
+  try {
+    templates = await owl.utils.loadFile('app.xml');
+  } catch(e) {
+    console.error(\`This app requires a static server.  If you have python installed, try 'python app.py'\`);
+    return;
+  }
+  const env = { qweb: new owl.QWeb({templates})};
+  owl.Component.env = env;
+  await owl.utils.whenReady();
+  app();
+}
+
+start();
 `;
 
   zip.file("app.js", JS);
@@ -310,7 +319,6 @@ class App extends owl.Component {
       js: this.SAMPLES[0].code,
       css: this.SAMPLES[0].css || "",
       xml: this.SAMPLES[0].xml || DEFAULT_XML,
-      error: false,
       displayWelcome: true,
       splitLayout: true,
       leftPaneWidth: Math.ceil(window.innerWidth / 2),
@@ -323,37 +331,12 @@ class App extends owl.Component {
     this.content = useRef("content");
   }
 
-  displayError(error) {
-    this.state.error = error;
-    if (error) {
-      setTimeout(() => {
-        this.content.el.innerHTML = "";
-      });
-      return;
-    }
-  }
-
   runCode() {
-    this.state.displayWelcome = false;
-    let subiframe;
-    let error = false;
-    const errorHandler = e => this.displayError(e.message || e.reason.message);
-    try {
-      const { js, css, xml } = this.state;
-      subiframe = makeCodeIframe(js, css, xml, errorHandler);
-    } catch (e) {
-      //probably problem with the templates
-      error = e;
-      // we still log the error, always useful to have it available
-      console.error(e);
-    }
-    if (error) {
-      this.displayError(error.message);
-      return;
-    } else {
-      this.state.error = false;
-    }
     this.content.el.innerHTML = "";
+    this.state.displayWelcome = false;
+
+    const { js, css, xml } = this.state;
+    const subiframe = makeCodeIframe(js, css, xml);
     this.content.el.appendChild(subiframe);
   }
 
@@ -436,7 +419,8 @@ async function start() {
     owl.utils.whenReady()
   ]);
   const qweb = new owl.QWeb({ templates });
-  const app = new App({ qweb });
+  owl.Component.env = { qweb };
+  const app = new App();
   app.mount(document.body);
 }
 

tools/playground/playground.css

@@ -179,16 +179,3 @@ body {
   padding: 5%;
 }
 
-.right-pane .error {
-  height: 100%;
-  width: 90%;
-  padding-top: 30%;
-  font-size: 18px;
-  color: darkred;
-  margin-left: 5%;
-}
-
-.right-pane .error pre {
-    overflow: auto;
-    width: 100%;
-}

tools/playground/samples.js

@@ -16,9 +16,7 @@ class App extends Component {
 App.components = { Greeter };
 
 // Application setup
-// Note that the xml templates are injected into the global TEMPLATES variable.
-const qweb = new owl.QWeb({ templates: TEMPLATES});
-const app = new App({ qweb });
+const app = new App();
 app.mount(document.body);
 `;
 
@@ -70,8 +68,7 @@ class App extends Component {
 }
 App.components = { Counter };
 
-const qweb = new owl.QWeb({ templates: TEMPLATES});
-const app = new App({qweb});
+const app = new App();
 app.mount(document.body);
 `;
 
@@ -228,8 +225,7 @@ class App extends Component {
 }
 App.components = { DemoComponent };
 
-const qweb = new owl.QWeb({ templates: TEMPLATES});
-const app = new App({ qweb });
+const app = new App();
 app.mount(document.body);
 `;
 
@@ -298,8 +294,7 @@ class App extends owl.Component {
 }
 
 // Application setup
-const qweb = new owl.QWeb({ templates: TEMPLATES});
-const app = new App({ qweb });
+const app = new App();
 app.mount(document.body);
 `;
 
@@ -349,11 +344,9 @@ const themeContext = new Context({
    background: '#000',
    foreground: '#fff',
 });
-const env = {
-    qweb: new owl.QWeb({ templates: TEMPLATES}),
-    themeContext: themeContext,
-};
-const app = new App(env);
+// Add the themeContext the environment to make it available to all components
+App.env.themeContext = themeContext;
+const app = new App();
 app.mount(document.body);
 `;
 
@@ -534,26 +527,25 @@ TodoApp.components = { TodoItem };
 //------------------------------------------------------------------------------
 // App Initialization
 //------------------------------------------------------------------------------
-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;
-}
+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;
+    }
 
-function makeEnv() {
     const state = loadState();
     const store = new owl.Store({ state, actions });
     store.on("update", null, () => saveState(store.state));
-    const qweb = new owl.QWeb({ templates: TEMPLATES});
-    return { qweb, store };
+    return store;
 }
 
-const env = makeEnv();
-const app = new TodoApp(env);
+TodoApp.env.store = makeStore();
+const app = new TodoApp();
 app.mount(document.body);
 `;
 
@@ -1040,12 +1032,9 @@ function setupResponsivePlugin(env) {
 //------------------------------------------------------------------------------
 // Application Startup
 //------------------------------------------------------------------------------
-const env = {
-    qweb: new owl.QWeb({ templates: TEMPLATES}),
-};
-setupResponsivePlugin(env);
+setupResponsivePlugin(App.env);
 
-const app = new App(env);
+const app = new App();
 app.mount(document.body);
 `;
 
@@ -1187,8 +1176,7 @@ class App extends Component {
 App.components = {Card, Counter};
 
 // Application setup
-const qweb = new owl.QWeb({ templates: TEMPLATES});
-const app = new App({ qweb });
+const app = new App();
 app.mount(document.body);`;
 
 const SLOTS_XML = `<templates>
@@ -1301,10 +1289,9 @@ class App extends Component {
         }, 3000);
     }
 }
-App.components = {SlowComponent, NotificationList};
+App.components = {SlowComponent, NotificationList, AsyncRoot};
 
-const qweb = new owl.QWeb({ templates: TEMPLATES});
-const app = new App({ qweb });
+const app = new App();
 app.mount(document.body);
 `;
 
@@ -1373,8 +1360,7 @@ class Form extends Component {
 }
 
 // Application setup
-const qweb = new owl.QWeb({ templates: TEMPLATES});
-const form = new Form({ qweb });
+const form = new Form();
 form.mount(document.body);
 `;
 
@@ -1540,7 +1526,6 @@ class App extends Component {
 }
 App.components = { WindowManager };
 
-const qweb = new owl.QWeb({ templates: TEMPLATES});
 const windows = [
   {
     name: "Hello",
@@ -1558,8 +1543,8 @@ const windows = [
   }
 ];
 
-const env = { qweb, windows };
-const app = new App(env);
+App.env.windows = windows;
+const app = new App();
 app.mount(document.body);
 `;
 

tools/playground/templates.xml

@@ -31,7 +31,7 @@
             t-att-style="topEditorStyle"/>
         <t t-if="state.splitLayout">
           <div class="separator horizontal"/>
-          <TabbedEditor t-keepalive="1"
+          <TabbedEditor
              js="false"
              css="state.css"
              xml="state.xml"
@@ -51,10 +51,6 @@
             </p>
           </div>
         </div>
-        <div t-if="state.error" class="error">
-          <h3>Error</h3>
-          <pre t-esc="state.error"/>
-        </div>
         <div class="content" t-ref="content"/>
       </div>
   </div>