[FIX] component: various issues while mounting manually components

The initial problem solved by this commit is that it was possible to get
into a situation where a mounting/rendering was started, then the component was
updated, but then another mounting operation begins, and it tries to
reuse the previous rendering operation, which is no longer uptodate.

The underlying issue is that Owl did not track properly the various
internal state change of a component.  These issue should be solved by
the introduction of the status enum, which currently tracks 6 possible
states:

- CREATED
- WILLSTARTED
- RENDERED
- MOUNTED
- UNMOUNTED
- DESTROYED

This status number replaces the isMounted and isDestroyed boolean flags.
It has the advantage of making sure that the component is in a
consistent state (it is no longer possible to be destroyed and mounted,
for example)

Another advantage is that it gives us an easy way to track the fact that
a component has been rendered, but is not in the DOM.  This is a subtle
situation where some various events can happen, and we need to be able
to react to that case.

Note that there is a change of behaviour: if a component is mounted in a
specific target, then before the mounting is complete, the component is
mounted in another target, we no longer reject the first mounting
operation.

README.md

@@ -120,7 +120,7 @@ npm install @odoo/owl
 
 If you want to use a simple `<script>` tag, the last release can be downloaded here:
 
-- [owl-1.1.1](https://github.com/odoo/owl/releases/tag/v1.1.1)
+- [owl-1.2.3](https://github.com/odoo/owl/releases/tag/v1.2.3)
 
 ## License
 

doc/learning/tutorial_todoapp.md

@@ -545,7 +545,7 @@ application), since it involves extracting all task related code out of the
 components. Here is the new content of the `app.js` file:
 
 ```js
-const { Component, Store } = owl;
+const { Component, Store, mount } = owl;
 const { xml } = owl.tags;
 const { whenReady } = owl.utils;
 const { useRef, useDispatch, useStore } = owl.hooks;
@@ -663,7 +663,7 @@ function makeStore() {
 
 function setup() {
   owl.config.mode = "dev";
-  const env = {store = makeStore()};
+  const env = { store: makeStore() };
   mount(App, { target: document.body, env });
 }
 ```
@@ -808,7 +808,7 @@ For reference, here is the final code:
 
 ```js
 (function () {
-  const { Component, Store } = owl;
+  const { Component, Store, mount } = owl;
   const { xml } = owl.tags;
   const { whenReady } = owl.utils;
   const { useRef, useDispatch, useState, useStore } = owl.hooks;
@@ -939,7 +939,7 @@ For reference, here is the final code:
 
   function setup() {
     owl.config.mode = "dev";
-    const env = {store = makeStore()};
+    const env = { store: makeStore() };
     mount(App, { target: document.body, env });
   }
 

doc/reference/component.md

@@ -10,13 +10,22 @@
   - [Static Properties](#static-properties)
   - [Methods](#methods)
   - [Lifecycle](#lifecycle)
+    - [`constructor(parent, props)`](#constructorparent-props)
+    - [`setup()`](#setup)
+    - [`willStart()`](#willstart)
+    - [`mounted()`](#mounted)
+    - [`willUpdateProps(nextProps)`](#willupdatepropsnextprops)
+    - [`willPatch()`](#willpatch)
+    - [`patched(snapshot)`](#patchedsnapshot)
+    - [`willUnmount()`](#willunmount)
+    - [`catchError(error)`](#catcherrorerror)
   - [Root Component](#root-component)
   - [Composition](#composition)
   - [Form Input Bindings](#form-input-bindings)
   - [References](#references)
   - [Dynamic sub components](#dynamic-sub-components)
   - [Functional Components](#functional-components)
-  - [SVG components](#svg-components)
+  - [SVG Components](#svg-components)
 
 ## Overview
 
@@ -289,8 +298,13 @@ We explain here all the public methods of the `Component` class.
   are updated. It returns a boolean, which indicates if the component should
   ignore a props update. If it returns false, then `willUpdateProps` will not
   be called, and no rendering will occur. Its default implementation is to
-  always return true. This is an optimization, similar to React's `shouldComponentUpdate`. Most of the time, this should not be used, but it
-  can be useful if we are handling large number of components.
+  always return true. Note that this is an optimization, similar to React's `shouldComponentUpdate`. Most of the time, this should not be used, but it
+  can be useful if we are handling large number of components. Since this is an
+  optimization, Owl has the freedom to ignore the result of `shouldUpdate` in
+  some cases (for example, if a component is remounted, or if we want to force
+  a full rerender of the UI). However, if `shouldUpdate` returns true, then Owl
+  provides the guarantee that the component will be rendered at some point in
+  the future (except if the component is destroyed or if some part of the UI crashes).
 
 * **`destroy()`**. As its name suggests, this method will remove the component,
   and perform all necessary cleanup, such as unmounting the component, its children,
@@ -311,7 +325,7 @@ a owl component:
 
 | Method                                           | Description                                                 |
 | ------------------------------------------------ | ----------------------------------------------------------- |
-| **[constructor](#constructorparent-props)**      | constructor                                                 |
+| **[setup](#setup)**                              | setup                                                       |
 | **[willStart](#willstart)**                      | async, before first rendering                               |
 | **[mounted](#mounted)**                          | just after component is rendered and added to the DOM       |
 | **[willUpdateProps](#willupdatepropsnextprops)** | async, before props update                                  |
@@ -356,6 +370,23 @@ class ClickCounter extends owl.Component {
 }
 ```
 
+Hook functions can be called in the constructor.
+
+#### `setup()`
+
+_setup_ is run just after the component is constructed. It is a lifecycle method,
+very similar to the _constructor_, except that it does not receive any argument.
+
+It is a valid method to call hook functions. Note that one of the main reason to
+have the `setup` hook in the component lifecycle is to make it possible to
+monkey patch it. It is a common need in the Odoo ecosystem.
+
+```javascript
+setup() {
+  useSetupAutofocus();
+}
+```
+
 #### `willStart()`
 
 willStart is an asynchronous hook that can be implemented to
@@ -758,7 +789,7 @@ template rendered with `props`. In Owl, this can be done by
 simply defining a template, that will access the `props` object:
 
 ```js
-const Welcome = xml`<h1>Hello, {props.name}</h1>`;
+const Welcome = xml`<h1>Hello, <t t-esc="props.name"/></h1>`;
 
 class MyComponent extends Component {
   static template = xml`

doc/reference/content.md

@@ -29,6 +29,8 @@ hooks                                   utils
     useContext
     useState
     useRef
+    useComponent
+    useEnv
     useSubEnv
     useStore
     useDispatch

doc/reference/hooks.md

@@ -21,6 +21,8 @@
   - [`useStore`](#usestore)
   - [`useDispatch`](#usedispatch)
   - [`useGetters`](#usegetters)
+  - [`useComponent`](#usecomponent)
+  - [`useEnv`](#useenv)
   - [Making customized hooks](#making-customized-hooks)
 
 ## Overview
@@ -129,7 +131,7 @@ class SomeComponent extends Component {
 ### One rule
 
 There is only one rule: every hook for a component has to be called in the
-constructor (or in class fields):
+constructor, in the _setup_ method, or in class fields:
 
 ```js
 // ok
@@ -145,6 +147,13 @@ class SomeComponent extends Component {
   }
 }
 
+// also ok
+class SomeComponent extends Component {
+  setup() {
+    this.state = useState({ value: 0 });
+  }
+}
+
 // not ok: this is executed after the constructor is called
 class SomeComponent extends Component {
   async willStart() {
@@ -381,6 +390,16 @@ The `useDispatch` hook is the way for components to get a reference to the store
 The `useGetters` hook is the way for components to get a reference to the store
 getters. See the [store documentation](store.md) for more information.
 
+### `useComponent`
+
+The `useComponent` hook is useful as a building block for some customized hooks,
+that may need a reference to the component calling them.
+
+### `useEnv`
+
+The `useEnv` hook is useful as a building block for some customized hooks,
+that may need a reference to the env of the component calling them.
+
 ### Making customized hooks
 
 Hooks are a wonderful way to organize the code of a complex component by feature
@@ -435,13 +454,11 @@ not the solution to every problem.
 
   ```js
   function useRouter() {
-    return Component.current.env.router;
+    const env = useEnv();
+    return env.router;
   }
   ```
 
   This means that we give control to the application developer to create the
   router, which is good, so they can set it up, subclass it, ... And then, to
   test our components, we can just add a mock router in the environment.
-
-Note: the code above makes use of the `Component.current` property. This is the
-way hooks are able to get a reference to the component currently being created.

doc/reference/observer.md

@@ -15,7 +15,7 @@ use cases, there is no need to directly instantiate an observer.
 For example, this code will display `update` in the console:
 
 ```javascript
-const observer = new owl.Observer();
+const observer = new owl.core.Observer();
 observer.notifyCB = () => console.log("update");
 const obj = observer.observe({ a: { b: 1 } });
 
@@ -39,14 +39,14 @@ is incremented every time the value is observed. Sometimes, it can be useful
 to obtain that number:
 
 ```js
-const observer = new owl.Observer();
+const observer = new owl.core.Observer();
 const obj = observer.observe({ a: { b: 1 } });
 
-observer.deepRevNumber(obj.a); // 1
+observer.revNumber(obj.a); // 1
 obj.a.b = 2;
 
-observer.deepRevNumber(obj.a); // 2
+observer.revNumber(obj.a); // 2
 ```
 
-The `deepRevNumber` can also return 0, which indicates that the value is not
+The `revNumber` can also return 0, which indicates that the value is not
 observed.

doc/reference/slots.md

@@ -44,7 +44,7 @@ Slots are defined by the caller, with the `t-set-slot` directive:
 ```xml
 <div t-name="SomeComponent">
   <div>some component</div>
-  <Dialog title="Some Dialog">
+  <Dialog title="'Some Dialog'">
     <t t-set-slot="content">
       <div>hey</div>
     </t>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@odoo/owl",
-  "version": "1.1.1",
+  "version": "1.2.3",
   "description": "Odoo Web Library (OWL)",
   "main": "dist/owl.cjs.js",
   "browser": "dist/owl.iife.js",

roadmap.md

@@ -1,6 +1,6 @@
 # 🦉 OWL Roadmap 🦉
 
-- Current version: 1.1.1
+- Current version: 1.2.3
 - Status: stable
 
 This roadmap is only an attempt at predicting Owl's future.  Everything may

src/component/component.ts

@@ -44,6 +44,15 @@ interface MountOptions {
   position?: MountPosition;
 }
 
+export const enum STATUS {
+  CREATED,
+  WILLSTARTED, // willstart has been called
+  RENDERED, // first render is completed (so, vnode is now defined)
+  MOUNTED, // is ready, and in DOM. It has a valid el
+  UNMOUNTED, // has a valid el, but is not in DOM
+  DESTROYED,
+}
+
 /**
  * This is mostly an internal detail of implementation. The Meta interface is
  * useful to typecheck and describe the internal keys used by Owl to manage the
@@ -56,8 +65,7 @@ interface Internal<T extends Env> {
   depth: number;
   vnode: VNode | null;
   pvnode: VNode | null;
-  isMounted: boolean;
-  isDestroyed: boolean;
+  status: STATUS;
 
   // parent and children keys are obviously useful to setup the parent-children
   // relationship.
@@ -164,16 +172,18 @@ export class Component<Props extends {} = any, T extends Env = Env> {
         this.env.browser = browser;
       }
       this.env.qweb.on("update", this, () => {
-        if (this.__owl__.isMounted) {
-          this.render(true);
-        }
-        if (this.__owl__.isDestroyed) {
-          // this is unlikely to happen, but if a root widget is destroyed,
-          // we want to remove our subscription.  The usual way to do that
-          // would be to perform some check in the destroy method, but since
-          // it is very performance sensitive, and since this is a rare event,
-          // we simply do it lazily
-          this.env.qweb.off("update", this);
+        switch (this.__owl__.status) {
+          case STATUS.MOUNTED:
+            this.render(true);
+            break;
+          case STATUS.DESTROYED:
+            // this is unlikely to happen, but if a root widget is destroyed,
+            // we want to remove our subscription.  The usual way to do that
+            // would be to perform some check in the destroy method, but since
+            // it is very performance sensitive, and since this is a rare event,
+            // we simply do it lazily
+            this.env.qweb.off("update", this);
+            break;
         }
       });
       depth = 0;
@@ -186,8 +196,7 @@ export class Component<Props extends {} = any, T extends Env = Env> {
       depth: depth,
       vnode: null,
       pvnode: null,
-      isMounted: false,
-      isDestroyed: false,
+      status: STATUS.CREATED,
       parent: parent || null,
       children: {},
       cmap: {},
@@ -209,8 +218,20 @@ export class Component<Props extends {} = any, T extends Env = Env> {
     if (constr.style) {
       this.__applyStyles(constr);
     }
+    this.setup();
   }
 
+  /**
+   * setup is run just after the component is constructed. This is the standard
+   * location where the component can setup its hooks. It has some advantages
+   * over the constructor:
+   *  - it can be patched (useful in odoo ecosystem)
+   *  - it does not need to propagate the arguments to the super call
+   *
+   * Note: this method should not be called manually.
+   */
+  setup() {}
+
   /**
    * willStart is an asynchronous hook that can be implemented to perform some
    * action before the initial rendering of a component.
@@ -305,42 +326,49 @@ export class Component<Props extends {} = any, T extends Env = Env> {
    * Note that a component can be mounted an unmounted several times
    */
   async mount(target: HTMLElement | DocumentFragment, options: MountOptions = {}): Promise<void> {
-    const position = options.position || "last-child";
-    const __owl__ = this.__owl__;
-    if (__owl__.isMounted) {
-      if (position !== "self" && this.el!.parentNode !== target) {
-        // in this situation, we are trying to mount a component on a different
-        // target. In this case, we need to unmount first, otherwise it will
-        // not work.
-        this.unmount();
-      } else {
-        return Promise.resolve();
-      }
-    }
-    if (__owl__.isDestroyed) {
-      throw new Error("Cannot mount a destroyed component");
-    }
-    if (__owl__.currentFiber) {
-      const currentFiber = __owl__.currentFiber;
-      if (currentFiber.target === target && currentFiber.position === position) {
-        return scheduler.addFiber(currentFiber);
-      } else {
-        scheduler.rejectFiber(currentFiber, "Mounting operation cancelled");
-      }
-    }
     if (!(target instanceof HTMLElement || target instanceof DocumentFragment)) {
       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, false, target, position);
-    fiber.shouldPatch = false;
-    if (!__owl__.vnode) {
-      this.__prepareAndRender(fiber, () => {});
-    } else {
-      this.__render(fiber);
+    const position = options.position || "last-child";
+    const __owl__ = this.__owl__;
+    const currentFiber = __owl__.currentFiber;
+
+    switch (__owl__.status) {
+      case STATUS.CREATED: {
+        const fiber = new Fiber(null, this, true, target, position);
+        fiber.shouldPatch = false;
+        this.__prepareAndRender(fiber, () => {});
+        return scheduler.addFiber(fiber);
+      }
+      case STATUS.WILLSTARTED:
+      case STATUS.RENDERED:
+        currentFiber.target = target;
+        currentFiber.position = position;
+        return scheduler.addFiber(currentFiber);
+
+      case STATUS.UNMOUNTED: {
+        const fiber = new Fiber(null, this, true, target, position);
+        fiber.shouldPatch = false;
+        this.__render(fiber);
+        return scheduler.addFiber(fiber);
+      }
+
+      case STATUS.MOUNTED: {
+        if (position !== "self" && this.el!.parentNode !== target) {
+          const fiber = new Fiber(null, this, true, target, position);
+          fiber.shouldPatch = false;
+          this.__render(fiber);
+          return scheduler.addFiber(fiber);
+        } else {
+          return Promise.resolve();
+        }
+      }
+
+      case STATUS.DESTROYED:
+        throw new Error("Cannot mount a destroyed component");
     }
-    return scheduler.addFiber(fiber);
   }
 
   /**
@@ -348,7 +376,7 @@ export class Component<Props extends {} = any, T extends Env = Env> {
    * to call willUnmount calls and remove the component from the DOM.
    */
   unmount() {
-    if (this.__owl__.isMounted) {
+    if (this.__owl__.status === STATUS.MOUNTED) {
       this.__callWillUnmount();
       this.el!.remove();
     }
@@ -366,10 +394,7 @@ export class Component<Props extends {} = any, T extends Env = Env> {
   async render(force: boolean = false): Promise<void> {
     const __owl__ = this.__owl__;
     const currentFiber = __owl__.currentFiber;
-    if (!__owl__.isMounted && !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.
+    if (!__owl__.vnode && !currentFiber) {
       return;
     }
     if (currentFiber && !currentFiber.isRendered && !currentFiber.isCompleted) {
@@ -378,15 +403,13 @@ export class Component<Props extends {} = any, T extends Env = Env> {
     // 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 status = __owl__.status;
     const fiber = new Fiber(null, this, force, null, null);
     Promise.resolve().then(() => {
-      if (__owl__.isMounted || !isMounted) {
-        if (fiber.isCompleted) {
+      if (__owl__.status === STATUS.MOUNTED || status !== STATUS.MOUNTED) {
+        if (fiber.isCompleted || fiber.isRendered) {
           return;
         }
-        // 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
@@ -410,7 +433,7 @@ export class Component<Props extends {} = any, T extends Env = Env> {
    */
   destroy() {
     const __owl__ = this.__owl__;
-    if (!__owl__.isDestroyed) {
+    if (__owl__.status !== STATUS.DESTROYED) {
       const el = this.el;
       this.__destroy(__owl__.parent);
       if (el) {
@@ -455,13 +478,12 @@ export class Component<Props extends {} = any, T extends Env = Env> {
    */
   __destroy(parent: Component | null) {
     const __owl__ = this.__owl__;
-    const isMounted = __owl__.isMounted;
-    if (isMounted) {
+    if (__owl__.status === STATUS.MOUNTED) {
       if (__owl__.willUnmountCB) {
         __owl__.willUnmountCB();
       }
       this.willUnmount();
-      __owl__.isMounted = false;
+      __owl__.status = STATUS.UNMOUNTED;
     }
     const children = __owl__.children;
     for (let key in children) {
@@ -472,7 +494,7 @@ export class Component<Props extends {} = any, T extends Env = Env> {
       delete parent.__owl__.children[id];
       __owl__.parent = null;
     }
-    __owl__.isDestroyed = true;
+    __owl__.status = STATUS.DESTROYED;
     delete __owl__.vnode;
     if (__owl__.currentFiber) {
       __owl__.currentFiber.isCompleted = true;
@@ -482,7 +504,7 @@ export class Component<Props extends {} = any, T extends Env = Env> {
   __callMounted() {
     const __owl__ = this.__owl__;
 
-    __owl__.isMounted = true;
+    __owl__.status = STATUS.MOUNTED;
     __owl__.currentFiber = null;
     this.mounted();
     if (__owl__.mountedCB) {
@@ -496,7 +518,7 @@ export class Component<Props extends {} = any, T extends Env = Env> {
       __owl__.willUnmountCB();
     }
     this.willUnmount();
-    __owl__.isMounted = false;
+    __owl__.status = STATUS.UNMOUNTED;
     if (__owl__.currentFiber) {
       __owl__.currentFiber.isCompleted = true;
       __owl__.currentFiber.root.counter = 0;
@@ -504,7 +526,7 @@ export class Component<Props extends {} = any, T extends Env = Env> {
     const children = __owl__.children;
     for (let id in children) {
       const comp = children[id];
-      if (comp.__owl__.isMounted) {
+      if (comp.__owl__.status === STATUS.MOUNTED) {
         comp.__callWillUnmount();
       }
     }
@@ -625,18 +647,25 @@ export class Component<Props extends {} = any, T extends Env = Env> {
     }
     return p._template;
   }
+
   async __prepareAndRender(fiber: Fiber, cb: CallableFunction) {
     try {
-      await Promise.all([this.willStart(), this.__owl__.willStartCB && this.__owl__.willStartCB()]);
+      const proms = Promise.all([
+        this.willStart(),
+        this.__owl__.willStartCB && this.__owl__.willStartCB(),
+      ]);
+      this.__owl__.status = STATUS.WILLSTARTED;
+      await proms;
+      if (this.__owl__.status === <any>STATUS.DESTROYED) {
+        return Promise.resolve();
+      }
     } catch (e) {
       fiber.handleError(e);
       return Promise.resolve();
     }
-    if (this.__owl__.isDestroyed) {
-      return Promise.resolve();
-    }
     if (!fiber.isCompleted) {
       this.__render(fiber);
+      this.__owl__.status = STATUS.RENDERED;
       cb();
     }
   }
@@ -659,7 +688,7 @@ export class Component<Props extends {} = any, T extends Env = Env> {
       for (let childKey in __owl__.children) {
         const child = __owl__.children[childKey];
         const childOwl = child.__owl__;
-        if (!childOwl.isMounted && childOwl.parentLastFiberId < fiber.id) {
+        if (childOwl.status !== STATUS.MOUNTED && childOwl.parentLastFiberId < fiber.id) {
           // we only do here a "soft" destroy, meaning that we leave the child
           // dom node alone, without removing it.  Most of the time, it does not
           // matter, because the child component is already unmounted.  However,
@@ -706,17 +735,6 @@ export class Component<Props extends {} = any, T extends Env = Env> {
     }
   }
 
-  /**
-   * Only called by qweb t-component directive (when t-keepalive is set)
-   */
-  __remount() {
-    const __owl__ = this.__owl__;
-    if (!__owl__.isMounted) {
-      __owl__.isMounted = true;
-      this.mounted();
-    }
-  }
-
   /**
    * Apply default props (only top level).
    *

src/component/directive.ts

@@ -1,6 +1,7 @@
 import { QWeb } from "../qweb/index";
 import { INTERP_REGEXP } from "../qweb/compilation_context";
 import { makeHandlerCode, MODS_CODE } from "../qweb/extensions";
+import { STATUS } from "./component";
 
 //------------------------------------------------------------------------------
 // t-component
@@ -361,7 +362,7 @@ QWeb.addDirective({
     // need to update component
     let styleCode = "";
     if (tattStyle) {
-      styleCode = `.then(()=>{if (w${componentID}.__owl__.isDestroyed) {return};w${componentID}.el.style=${tattStyle};});`;
+      styleCode = `.then(()=>{if (w${componentID}.__owl__.status === ${STATUS.DESTROYED}) {return};w${componentID}.el.style=${tattStyle};});`;
     }
     ctx.addLine(
       `w${componentID}.__updateProps(props${componentID}, extra.fiber, ${scope})${styleCode};`

src/component/fiber.ts

@@ -1,5 +1,5 @@
 import { h, VNode } from "../vdom/index";
-import { Component, MountPosition } from "./component";
+import { Component, MountPosition, STATUS } from "./component";
 import { scheduler } from "./scheduler";
 
 /**
@@ -82,6 +82,7 @@ export class Fiber {
 
     let oldFiber = __owl__.currentFiber;
     if (oldFiber && !oldFiber.isCompleted) {
+      this.force = true;
       if (oldFiber.root === oldFiber && !parent) {
         // both oldFiber and this fiber are root fibers
         this._reuseFiber(oldFiber);
@@ -106,6 +107,8 @@ export class Fiber {
    */
   _reuseFiber(oldFiber: Fiber) {
     oldFiber.cancel(); // cancel children fibers
+    oldFiber.target = this.target || oldFiber.target;
+    oldFiber.position = this.position || oldFiber.position;
     oldFiber.isCompleted = false; // keep the root fiber alive
     oldFiber.isRendered = false; // the fiber has to be re-rendered
     if (oldFiber.child) {
@@ -187,7 +190,8 @@ export class Fiber {
   complete() {
     let component = this.component;
     this.isCompleted = true;
-    if (!this.target && !component.__owl__.isMounted) {
+    const status = component.__owl__.status;
+    if (status === STATUS.DESTROYED) {
       return;
     }
 
@@ -201,14 +205,16 @@ export class Fiber {
     const patchLen = patchQueue.length;
 
     // call willPatch hook on each fiber of patchQueue
-    for (let i = 0; i < patchLen; i++) {
-      const fiber = patchQueue[i];
-      if (fiber.shouldPatch) {
-        component = fiber.component;
-        if (component.__owl__.willPatchCB) {
-          component.__owl__.willPatchCB();
+    if (status === STATUS.MOUNTED) {
+      for (let i = 0; i < patchLen; i++) {
+        const fiber = patchQueue[i];
+        if (fiber.shouldPatch) {
+          component = fiber.component;
+          if (component.__owl__.willPatchCB) {
+            component.__owl__.willPatchCB();
+          }
+          component.willPatch();
         }
-        component.willPatch();
       }
     }
 
@@ -249,8 +255,9 @@ export class Fiber {
           component.__owl__.pvnode!.elm = component.__owl__.vnode!.elm;
         }
       }
-      if (fiber === component.__owl__.currentFiber) {
-        component.__owl__.currentFiber = null;
+      const compOwl = component.__owl__;
+      if (fiber === compOwl.currentFiber) {
+        compOwl.currentFiber = null;
       }
     }
 
@@ -270,16 +277,24 @@ export class Fiber {
     }
 
     // call patched/mounted hook on each fiber of (reversed) patchQueue
-    for (let i = patchLen - 1; i >= 0; i--) {
-      const fiber = patchQueue[i];
-      component = fiber.component;
-      if (fiber.shouldPatch && !this.target) {
-        component.patched();
-        if (component.__owl__.patchedCB) {
-          component.__owl__.patchedCB();
+    if (status === STATUS.MOUNTED || inDOM) {
+      for (let i = patchLen - 1; i >= 0; i--) {
+        const fiber = patchQueue[i];
+        component = fiber.component;
+        if (fiber.shouldPatch && !this.target) {
+          component.patched();
+          if (component.__owl__.patchedCB) {
+            component.__owl__.patchedCB();
+          }
+        } else {
+          component.__callMounted();
         }
-      } else if (this.target ? inDOM : true) {
-        component.__callMounted();
+      }
+    } else {
+      for (let i = patchLen - 1; i >= 0; i--) {
+        const fiber = patchQueue[i];
+        component = fiber.component;
+        component.__owl__.status = STATUS.UNMOUNTED;
       }
     }
   }

src/context.ts

@@ -115,16 +115,6 @@ export function useContextWithCB(ctx: Context, component: Component, method): an
     __owl__.observer = new Observer();
     __owl__.observer.notifyCB = component.render.bind(component);
   }
-  const currentCB = __owl__.observer.notifyCB;
-  __owl__.observer.notifyCB = function () {
-    if (ctx.rev > mapping[id]) {
-      // in this case, the context has been updated since we were rendering
-      // last, and we do not need to render here with the observer. A
-      // rendering is coming anyway, with the correct props.
-      return;
-    }
-    currentCB();
-  };
 
   mapping[id] = 0;
   const renderFn = __owl__.renderFn;

src/hooks.ts

@@ -1,4 +1,4 @@
-import { Component } from "./component/component";
+import { Component, Env } from "./component/component";
 import { Observer } from "./core/observer";
 
 /**
@@ -118,6 +118,26 @@ export function useRef<C extends Component = Component>(name: string): Ref<C> {
   };
 }
 
+// -----------------------------------------------------------------------------
+// "Builder" hooks
+// -----------------------------------------------------------------------------
+
+/**
+ * This hook is useful as a building block for some customized hooks, that may
+ * need a reference to the component calling them.
+ */
+export function useComponent<P, E extends Env>(): Component<P, E> {
+  return Component.current as any;
+}
+
+/**
+ * This hook is useful as a building block for some customized hooks, that may
+ * need a reference to the env of the component calling them.
+ */
+export function useEnv<E extends Env>(): E {
+  return Component.current.env as any;
+}
+
 // -----------------------------------------------------------------------------
 // useSubEnv
 // -----------------------------------------------------------------------------

src/qweb/expression_parser.ts

@@ -29,14 +29,14 @@ const RESERVED_WORDS = "true,false,NaN,null,undefined,debugger,console,window,in
   ","
 );
 
-const WORD_REPLACEMENT = {
+const WORD_REPLACEMENT = Object.assign(Object.create(null), {
   and: "&&",
   or: "||",
   gt: ">",
   gte: ">=",
   lt: "<",
   lte: "<=",
-};
+});
 
 export interface QWebVar {
   id: string; // foo
@@ -69,7 +69,7 @@ interface Token {
   varName?: string;
 }
 
-const STATIC_TOKEN_MAP: { [key: string]: TKind } = {
+const STATIC_TOKEN_MAP: { [key: string]: TKind } = Object.assign(Object.create(null), {
   "{": "LEFT_BRACE",
   "}": "RIGHT_BRACE",
   "[": "LEFT_BRACKET",
@@ -78,7 +78,7 @@ const STATIC_TOKEN_MAP: { [key: string]: TKind } = {
   ",": "COMMA",
   "(": "LEFT_PAREN",
   ")": "RIGHT_PAREN",
-};
+});
 
 // note that the space after typeof is relevant. It makes sure that the formatted
 // expression has a space after typeof

src/qweb/extensions.ts

@@ -1,3 +1,4 @@
+import { STATUS } from "../component/component";
 import { VNode } from "../vdom/index";
 import { INTERP_REGEXP } from "./compilation_context";
 import { QWeb } from "./qweb";
@@ -76,7 +77,7 @@ export function makeHandlerCode(
     code = ctx.captureExpression(value);
   }
   const modCode = mods.map((mod) => modcodes[mod]).join("");
-  let handler = `function (e) {if (!context.__owl__.isMounted){return}${modCode}${code}}`;
+  let handler = `function (e) {if (context.__owl__.status === ${STATUS.DESTROYED}){return}${modCode}${code}}`;
   if (putInCache) {
     const key = ctx.generateTemplateKey(event);
     ctx.addLine(`extra.handlers[${key}] = extra.handlers[${key}] || ${handler};`);

src/qweb/qweb.ts

@@ -70,6 +70,7 @@ const TRANSLATABLE_ATTRS = ["label", "title", "placeholder", "alt"];
 
 const lineBreakRE = /[\r\n]/;
 const whitespaceRE = /\s+/g;
+const translationRE = /^(\s*)([\s\S]+?)(\s*)$/;
 
 const NODE_HOOKS_PARAMS = {
   create: "(_, n)",
@@ -496,7 +497,8 @@ export class QWeb extends EventBus {
       }
       if (this.translateFn) {
         if ((node.parentNode as any).getAttribute("t-translation") !== "off") {
-          text = this.translateFn(text);
+          const match = translationRE.exec(text);
+          text = match[1] + this.translateFn(match[2]) + match[3];
         }
       }
       if (ctx.parentNode) {

src/store.ts

@@ -1,5 +1,4 @@
-import { Component } from "./component/component";
-import { Env } from "./component/component";
+import { Component, Env } from "./component/component";
 import { Context, useContextWithCB } from "./context";
 import { onWillUpdateProps } from "./hooks";
 
@@ -76,6 +75,11 @@ export class Store extends Context {
     );
     return result;
   }
+
+  __notifyComponents(): Promise<void> {
+    this.trigger("before-update");
+    return super.__notifyComponents();
+  }
 }
 
 interface SelectorOptions {
@@ -106,13 +110,16 @@ export function useStore(selector, options: SelectorOptions = {}): any {
     const newRevNumber = hashFn(result);
     if ((newRevNumber > 0 && revNumber !== newRevNumber) || !isEqual(oldResult, result)) {
       revNumber = newRevNumber;
-      if (options.onUpdate) {
-        options.onUpdate(result);
-      }
       return true;
     }
     return false;
   }
+  if (options.onUpdate) {
+    store.on("before-update", component, () => {
+      const newValue = selector(store!.state, component.props!);
+      options.onUpdate(newValue);
+    });
+  }
   store.updateFunctions[componentId].push(function (): boolean {
     return selectCompareUpdate(store!.state, component.props);
   });
@@ -133,6 +140,9 @@ export function useStore(selector, options: SelectorOptions = {}): any {
   const __destroy = component.__destroy;
   component.__destroy = (parent) => {
     delete store.updateFunctions[componentId];
+    if (options.onUpdate) {
+      store.off("before-update", component);
+    }
     __destroy.call(component, parent);
   };
 

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

@@ -20,7 +20,7 @@ exports[`class and style attributes with t-component dynamic t-att-style is prop
         w2 = false;
     }
     if (w2) {
-        w2.__updateProps(props2, extra.fiber, undefined).then(()=>{if (w2.__owl__.isDestroyed) {return};w2.el.style=_4;});;
+        w2.__updateProps(props2, extra.fiber, undefined).then(()=>{if (w2.__owl__.status === 5) {return};w2.el.style=_4;});;
         let pvnode = w2.__owl__.pvnode;
         c1.push(pvnode);
     } else {

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

@@ -444,7 +444,7 @@ exports[`composition t-ref on a node, and t-on-click 2`] = `
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
         parent.__owl__.cmap['__3__'] = w2.__owl__.id;
-        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('click', function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['doSomething'](e);});}});});
+        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('click', function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['doSomething'](e);});}});});
         let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
@@ -579,7 +579,7 @@ exports[`other directives with t-component t-on expression captured in t-foreach
         c6.push(vn7);
         const otherState_8 = scope['otherState'];
         const iter_8 = scope.iter;
-        p7.on['click'] = function (e) {if (!context.__owl__.isMounted){return}otherState_8.vals.push(iter_8+'_'+iter_8)};
+        p7.on['click'] = function (e) {if (context.__owl__.status === 5){return}otherState_8.vals.push(iter_8+'_'+iter_8)};
         c7.push({text: \`expr\`});
         utils.getScope(scope, 'iter').iter = scope.iter+1;
     }
@@ -630,7 +630,7 @@ exports[`other directives with t-component t-on expression in t-foreach 1`] = `
         c6.push(vn9);
         const otherState_10 = scope['otherState'];
         const val_10 = scope['val'];
-        p9.on['click'] = function (e) {if (!context.__owl__.isMounted){return}otherState_10.vals.push(val_10)};
+        p9.on['click'] = function (e) {if (context.__owl__.status === 5){return}otherState_10.vals.push(val_10)};
         c9.push({text: \`Expr\`});
     }
     scope = _origScope5;
@@ -684,7 +684,7 @@ exports[`other directives with t-component t-on expression in t-foreach with t-s
         const otherState_10 = scope['otherState'];
         const val_10 = scope['val'];
         const bossa_10 = scope.bossa;
-        p9.on['click'] = function (e) {if (!context.__owl__.isMounted){return}otherState_10.vals.push(val_10+'_'+bossa_10)};
+        p9.on['click'] = function (e) {if (context.__owl__.status === 5){return}otherState_10.vals.push(val_10+'_'+bossa_10)};
         c9.push({text: \`Expr\`});
     }
     scope = _origScope5;
@@ -734,7 +734,7 @@ exports[`other directives with t-component t-on method call in t-foreach 1`] = `
         let vn9 = h('button', p9, c9);
         c6.push(vn9);
         let args10 = [scope['val']];
-        p9.on['click'] = function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['addVal'](...args10, e);};
+        p9.on['click'] = function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['addVal'](...args10, e);};
         c9.push({text: \`meth call\`});
     }
     scope = _origScope5;
@@ -770,7 +770,7 @@ exports[`other directives with t-component t-on with .capture modifier 1`] = `
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
         parent.__owl__.cmap['__3__'] = w2.__owl__.id;
-        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('click', function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['capture'](e);}, true);}});});
+        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('click', function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['capture'](e);}, true);}});});
         let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
@@ -812,7 +812,7 @@ exports[`other directives with t-component t-on with getter as handler 1`] = `
         if (!W3) {throw new Error('Cannot find the definition of component \\"' + componentKey3 + '\\"')}
         w3 = new W3(parent, props3);
         parent.__owl__.cmap['__4__'] = w3.__owl__.id;
-        let fiber = w3.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['handler'](e);});}});});
+        let fiber = w3.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['handler'](e);});}});});
         let pvnode = h('dummy', {key: '__4__', hook: {remove() {},destroy(vn) {w3.destroy();}}});
         c1.push(pvnode);
         w3.__owl__.pvnode = pvnode;
@@ -851,7 +851,7 @@ exports[`other directives with t-component t-on with handler bound to argument 1
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
         parent.__owl__.cmap['__3__'] = w2.__owl__.id;
-        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['onEv'](...args4, e);});}});});
+        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['onEv'](...args4, e);});}});});
         let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
@@ -890,7 +890,7 @@ exports[`other directives with t-component t-on with handler bound to empty obje
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
         parent.__owl__.cmap['__3__'] = w2.__owl__.id;
-        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['onEv'](...args4, e);});}});});
+        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['onEv'](...args4, e);});}});});
         let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
@@ -929,7 +929,7 @@ exports[`other directives with t-component t-on with handler bound to empty obje
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
         parent.__owl__.cmap['__3__'] = w2.__owl__.id;
-        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['onEv'](...args4, e);});}});});
+        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['onEv'](...args4, e);});}});});
         let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
@@ -968,7 +968,7 @@ exports[`other directives with t-component t-on with handler bound to object 1`]
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
         parent.__owl__.cmap['__3__'] = w2.__owl__.id;
-        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['onEv'](...args4, e);});}});});
+        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['onEv'](...args4, e);});}});});
         let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
@@ -1011,7 +1011,7 @@ exports[`other directives with t-component t-on with inline statement 1`] = `
         if (!W3) {throw new Error('Cannot find the definition of component \\"' + componentKey3 + '\\"')}
         w3 = new W3(parent, props3);
         parent.__owl__.cmap['__4__'] = w3.__owl__.id;
-        let fiber = w3.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (!context.__owl__.isMounted){return}state_5.counter++});}});});
+        let fiber = w3.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (context.__owl__.status === 5){return}state_5.counter++});}});});
         let pvnode = h('dummy', {key: '__4__', hook: {remove() {},destroy(vn) {w3.destroy();}}});
         c1.push(pvnode);
         w3.__owl__.pvnode = pvnode;
@@ -1049,7 +1049,7 @@ exports[`other directives with t-component t-on with no handler (only modifiers)
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
         parent.__owl__.cmap['__3__'] = w2.__owl__.id;
-        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['onEv'](e);});}});});
+        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['onEv'](e);});}});});
         let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
@@ -1087,7 +1087,7 @@ exports[`other directives with t-component t-on with prevent and self modifiers
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
         parent.__owl__.cmap['__3__'] = w2.__owl__.id;
-        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (!context.__owl__.isMounted){return}e.preventDefault();if (e.target !== vn.elm) {return}utils.getComponent(context)['onEv'](e);});}});});
+        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (context.__owl__.status === 5){return}e.preventDefault();if (e.target !== vn.elm) {return}utils.getComponent(context)['onEv'](e);});}});});
         let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
@@ -1125,7 +1125,7 @@ exports[`other directives with t-component t-on with self and prevent modifiers
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
         parent.__owl__.cmap['__3__'] = w2.__owl__.id;
-        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (!context.__owl__.isMounted){return}if (e.target !== vn.elm) {return}e.preventDefault();utils.getComponent(context)['onEv'](e);});}});});
+        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (context.__owl__.status === 5){return}if (e.target !== vn.elm) {return}e.preventDefault();utils.getComponent(context)['onEv'](e);});}});});
         let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
@@ -1163,7 +1163,7 @@ exports[`other directives with t-component t-on with self modifier 1`] = `
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
         parent.__owl__.cmap['__3__'] = w2.__owl__.id;
-        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev-1', function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['onEv1'](e);});vn.elm.addEventListener('ev-2', function (e) {if (!context.__owl__.isMounted){return}if (e.target !== vn.elm) {return}utils.getComponent(context)['onEv2'](e);});}});});
+        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev-1', function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['onEv1'](e);});vn.elm.addEventListener('ev-2', function (e) {if (context.__owl__.status === 5){return}if (e.target !== vn.elm) {return}utils.getComponent(context)['onEv2'](e);});}});});
         let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
@@ -1201,7 +1201,7 @@ exports[`other directives with t-component t-on with stop and/or prevent modifie
         if (!W2) {throw new Error('Cannot find the definition of component \\"' + componentKey2 + '\\"')}
         w2 = new W2(parent, props2);
         parent.__owl__.cmap['__3__'] = w2.__owl__.id;
-        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev-1', function (e) {if (!context.__owl__.isMounted){return}e.stopPropagation();utils.getComponent(context)['onEv1'](e);});vn.elm.addEventListener('ev-2', function (e) {if (!context.__owl__.isMounted){return}e.preventDefault();utils.getComponent(context)['onEv2'](e);});vn.elm.addEventListener('ev-3', function (e) {if (!context.__owl__.isMounted){return}e.stopPropagation();e.preventDefault();utils.getComponent(context)['onEv3'](e);});}});});
+        let fiber = w2.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev-1', function (e) {if (context.__owl__.status === 5){return}e.stopPropagation();utils.getComponent(context)['onEv1'](e);});vn.elm.addEventListener('ev-2', function (e) {if (context.__owl__.status === 5){return}e.preventDefault();utils.getComponent(context)['onEv2'](e);});vn.elm.addEventListener('ev-3', function (e) {if (context.__owl__.status === 5){return}e.stopPropagation();e.preventDefault();utils.getComponent(context)['onEv3'](e);});}});});
         let pvnode = h('dummy', {key: '__3__', hook: {remove() {},destroy(vn) {w2.destroy();}}});
         c1.push(pvnode);
         w2.__owl__.pvnode = pvnode;
@@ -1555,7 +1555,7 @@ exports[`random stuff/miscellaneous t-on with handler bound to dynamic argument
                 if (!W6) {throw new Error('Cannot find the definition of component \\"' + componentKey6 + '\\"')}
                 w6 = new W6(parent, props6);
                 parent.__owl__.cmap[k7] = w6.__owl__.id;
-                let fiber = w6.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['onEv'](...args8, e);});}});});
+                let fiber = w6.__prepare(extra.fiber, undefined, () => { const vnode = fiber.vnode; pvnode.sel = vnode.sel; utils.assignHooks(vnode.data, {create(_, vn){vn.elm.addEventListener('ev', function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['onEv'](...args8, e);});}});});
                 let pvnode = h('dummy', {key: k7, hook: {remove() {},destroy(vn) {w6.destroy();}}});
                 c1.push(pvnode);
                 w6.__owl__.pvnode = pvnode;
@@ -1580,7 +1580,7 @@ exports[`t-call handlers are properly bound through a t-call 1`] = `
     let vn3 = h('p', p3, c3);
     c2.push(vn3);
     let k4 = \`click__4__\${key0}__\`;
-    extra.handlers[k4] = extra.handlers[k4] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['update'](e);};
+    extra.handlers[k4] = extra.handlers[k4] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['update'](e);};
     p3.on['click'] = extra.handlers[k4];
     c3.push({text: \`lucas\`});
 }"
@@ -1599,7 +1599,7 @@ exports[`t-call handlers with arguments are properly bound through a t-call 1`]
     let vn3 = h('p', p3, c3);
     c2.push(vn3);
     let args4 = [scope['a']];
-    p3.on['click'] = function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['update'](...args4, e);};
+    p3.on['click'] = function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['update'](...args4, e);};
     c3.push({text: \`lucas\`});
 }"
 `;

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

@@ -229,7 +229,7 @@ exports[`t-slot directive dynamic t-slot call 1`] = `
     let h = this.h;
     let c10 = [], p10 = {key:10,on:{}};
     let vn10 = h('button', p10, c10);
-    extra.handlers['click__11__'] = extra.handlers['click__11__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['toggle'](e);};
+    extra.handlers['click__11__'] = extra.handlers['click__11__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['toggle'](e);};
     p10.on['click'] = extra.handlers['click__11__'];
     const slot12 = this.constructor.slots[context.__owl__.slotId + '_' + (scope['current'].slot)];
     if (slot12) {
@@ -301,7 +301,7 @@ exports[`t-slot directive refs are properly bound in slots 1`] = `
     let c9 = [], p9 = {key:9,on:{}};
     let vn9 = h('button', p9, c9);
     c8.push(vn9);
-    extra.handlers['click__10__'] = extra.handlers['click__10__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['doSomething'](e);};
+    extra.handlers['click__10__'] = extra.handlers['click__10__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['doSomething'](e);};
     p9.on['click'] = extra.handlers['click__10__'];
     const ref11 = \`myButton\`;
     p9.hook = {
@@ -326,7 +326,7 @@ exports[`t-slot directive slots are rendered with proper context 1`] = `
     let c9 = [], p9 = {key:9,on:{}};
     let vn9 = h('button', p9, c9);
     c8.push(vn9);
-    extra.handlers['click__10__'] = extra.handlers['click__10__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['doSomething'](e);};
+    extra.handlers['click__10__'] = extra.handlers['click__10__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['doSomething'](e);};
     p9.on['click'] = extra.handlers['click__10__'];
     c9.push({text: \`do something\`});
 }"

tests/component/async.test.ts

@@ -1,4 +1,4 @@
-import { Component, Env } from "../../src/component/component";
+import { Component, Env, STATUS } from "../../src/component/component";
 import { useState } from "../../src/hooks";
 import { xml } from "../../src/tags";
 import { makeDeferred, makeTestEnv, makeTestFixture, nextMicroTick, nextTick } from "../helpers";
@@ -40,14 +40,14 @@ describe("async rendering", () => {
       }
     }
     const w = new W();
+    expect(w.__owl__.status).toBe(STATUS.CREATED);
     w.mount(fixture);
-    expect(w.__owl__.isDestroyed).toBe(false);
-    expect(w.__owl__.isMounted).toBe(false);
+    expect(w.__owl__.status).toBe(STATUS.WILLSTARTED);
     w.destroy();
+    expect(w.__owl__.status).toBe(STATUS.DESTROYED);
     def.resolve();
     await nextTick();
-    expect(w.__owl__.isDestroyed).toBe(true);
-    expect(w.__owl__.isMounted).toBe(false);
+    expect(w.__owl__.status).toBe(STATUS.DESTROYED);
   });
 
   test("destroying/recreating a subwidget with different props (if start is not over)", async () => {
@@ -1405,4 +1405,160 @@ describe("async rendering", () => {
     expect(fixture.innerHTML).toBe("<div>2</div>");
     expect(Widget.prototype.__render).toHaveBeenCalledTimes(2);
   });
+
+  test("components with shouldUpdate=false", async () => {
+    const state = { p: 1, cc: 10 };
+
+    class ChildChild extends Component {
+      static template = xml`
+        <div>
+          child child: <t t-esc="state.cc"/>
+        </div>`;
+      state = state;
+      shouldUpdate() {
+        return false;
+      }
+    }
+
+    class Child extends Component {
+      static components = { ChildChild };
+      static template = xml`
+        <div>
+          child
+          <ChildChild/>
+        </div>`;
+
+      shouldUpdate() {
+        return false;
+      }
+    }
+
+    let parent: any;
+    class Parent extends Component {
+      static components = { Child };
+      static template = xml`
+        <div>
+          parent: <t t-esc="state.p"/>
+          <Child/>
+        </div>`;
+
+      state = state;
+      constructor(a, b) {
+        super(a, b);
+        parent = this;
+      }
+      shouldUpdate() {
+        return false;
+      }
+    }
+
+    class App extends Component {
+      static components = { Parent };
+      static template = xml`
+        <div>
+          <Parent/>
+        </div>`;
+    }
+
+    var div = document.createElement("div");
+    fixture.appendChild(div);
+
+    const app = new App();
+
+    await app.mount(fixture);
+    expect(fixture.innerHTML).toBe(
+      "<div></div><div><div> parent: 1<div> child <div> child child: 10</div></div></div></div>"
+    );
+    app.mount(div);
+
+    // wait for rendering from second mount to go through parent
+    await Promise.resolve();
+    await Promise.resolve();
+    state.cc++;
+    state.p++;
+    parent.render();
+    await nextTick();
+    expect(fixture.innerHTML).toBe(
+      "<div><div><div> parent: 2<div> child <div> child child: 11</div></div></div></div></div>"
+    );
+  });
+
+  test("components with shouldUpdate=false, part 2", async () => {
+    const state = { p: 1, cc: 10 };
+    let shouldUpdate = true;
+
+    class ChildChild extends Component {
+      static template = xml`
+        <div>
+          child child: <t t-esc="state.cc"/>
+        </div>`;
+      state = state;
+      shouldUpdate() {
+        return shouldUpdate;
+      }
+    }
+
+    class Child extends Component {
+      static components = { ChildChild };
+      static template = xml`
+        <div>
+          child
+          <ChildChild/>
+        </div>`;
+
+      shouldUpdate() {
+        return shouldUpdate;
+      }
+    }
+
+    let parent: any;
+    class Parent extends Component {
+      static components = { Child };
+      static template = xml`
+        <div>
+          parent: <t t-esc="state.p"/>
+          <Child/>
+        </div>`;
+
+      state = state;
+      constructor(a, b) {
+        super(a, b);
+        parent = this;
+      }
+      shouldUpdate() {
+        return shouldUpdate;
+      }
+    }
+
+    class App extends Component {
+      static components = { Parent };
+      static template = xml`
+        <div>
+          <Parent/>
+        </div>`;
+    }
+
+    const app = new App();
+
+    await app.mount(fixture);
+    expect(fixture.innerHTML).toBe(
+      "<div><div> parent: 1<div> child <div> child child: 10</div></div></div></div>"
+    );
+
+    state.cc++;
+    state.p++;
+    app.render();
+
+    // wait for rendering to go through child
+    await Promise.resolve();
+    await Promise.resolve();
+    await Promise.resolve();
+
+    shouldUpdate = false;
+    parent.render();
+    await nextTick();
+    expect(fixture.innerHTML).toBe(
+      "<div><div> parent: 2<div> child <div> child child: 11</div></div></div></div>"
+    );
+  });
 });

tests/component/component.test.ts

@@ -1,4 +1,4 @@
-import { Component, Env, mount } from "../../src/component/component";
+import { Component, Env, mount, STATUS } from "../../src/component/component";
 import { EventBus } from "../../src/core/event_bus";
 import { useRef, useState } from "../../src/hooks";
 import { QWeb } from "../../src/qweb/qweb";
@@ -163,7 +163,7 @@ describe("basic widget properties", () => {
     expect(fixture.innerHTML).toBe("<div><span></span></div>");
   });
 
-  test("cannot be clicked on and updated if not in DOM", async () => {
+  test("can be clicked on and updated if not in DOM", async () => {
     class Counter extends Component {
       static template = xml`
       <div><t t-esc="state.counter"/><button t-on-click="state.counter++">Inc</button></div>`;
@@ -178,8 +178,8 @@ describe("basic widget properties", () => {
     const button = (<HTMLElement>counter.el).getElementsByTagName("button")[0];
     button.click();
     await nextTick();
-    expect(target.innerHTML).toBe("<div>0<button>Inc</button></div>");
-    expect(counter.state.counter).toBe(0);
+    expect(target.innerHTML).toBe("<div>1<button>Inc</button></div>");
+    expect(counter.state.counter).toBe(1);
   });
 
   test("widget style and classname", async () => {
@@ -661,9 +661,8 @@ describe("lifecycle hooks", () => {
 
     class ChildWidget extends Component {
       static template = xml`<div/>`;
-      constructor(parent) {
-        super(parent);
-        steps.push("init");
+      setup() {
+        steps.push("setup");
       }
       async willStart() {
         steps.push("willstart");
@@ -687,10 +686,10 @@ describe("lifecycle hooks", () => {
 
     const widget = new ParentWidget();
     await widget.mount(fixture);
-    expect(steps).toEqual(["init", "willstart", "mounted"]);
+    expect(steps).toEqual(["setup", "willstart", "mounted"]);
     widget.state.ok = false;
     await nextTick();
-    expect(steps).toEqual(["init", "willstart", "mounted", "willunmount"]);
+    expect(steps).toEqual(["setup", "willstart", "mounted", "willunmount"]);
   });
 
   test("components are unmounted and destroyed if no longer in DOM, even after updateprops", async () => {
@@ -738,8 +737,7 @@ describe("lifecycle hooks", () => {
 
     class ChildWidget extends Component {
       static template = xml`<div/>`;
-      constructor(parent) {
-        super(parent);
+      setup() {
         steps.push("c init");
       }
       async willStart() {
@@ -755,8 +753,7 @@ describe("lifecycle hooks", () => {
     class ParentWidget extends Component {
       static template = xml`<div><t t-component="child"/></div>`;
       static components = { child: ChildWidget };
-      constructor(parent?) {
-        super(parent);
+      setup() {
         steps.push("p init");
       }
       async willStart() {
@@ -962,6 +959,69 @@ describe("lifecycle hooks", () => {
       "parent:patched",
     ]);
   });
+
+  test("willPatch/patched hook is not called if not mounted in DOM", async () => {
+    const steps: string[] = [];
+
+    class ChildWidget extends Component {
+      static template = xml`<div/>`;
+      constructor(parent, props) {
+        super(parent, props);
+        steps.push("child:constructor");
+      }
+      mounted() {
+        steps.push("child:mounted");
+      }
+      willPatch() {
+        steps.push("child:willPatch");
+      }
+      patched() {
+        steps.push("child:patched");
+      }
+    }
+    class ParentWidget extends Component {
+      static template = xml`
+        <div>
+          <t t-component="child" v="state.n"/>
+        </div>
+      `;
+      static components = { child: ChildWidget };
+      state = useState({ n: 1 });
+      constructor() {
+        super();
+        steps.push("parent:constructor");
+      }
+      mounted() {
+        steps.push("parent:mounted");
+      }
+      willPatch() {
+        steps.push("parent:willPatch");
+      }
+      patched() {
+        steps.push("parent:patched");
+      }
+    }
+
+    const div = document.createElement("div");
+    const widget = new ParentWidget();
+    await widget.mount(div);
+    expect(steps).toEqual(["parent:constructor", "child:constructor"]);
+
+    widget.state.n = 2;
+    await nextTick();
+
+    expect(steps).toEqual(["parent:constructor", "child:constructor"]);
+
+    // then we remount the component in the dom
+    await widget.mount(fixture);
+
+    expect(steps).toEqual([
+      "parent:constructor",
+      "child:constructor",
+      "child:mounted",
+      "parent:mounted",
+    ]);
+  });
 });
 
 describe("destroy method", () => {
@@ -975,8 +1035,7 @@ describe("destroy method", () => {
     expect(document.contains(widget.el)).toBe(true);
     widget.destroy();
     expect(document.contains(widget.el)).toBe(false);
-    expect(widget.__owl__.isMounted).toBe(false);
-    expect(widget.__owl__.isDestroyed).toBe(true);
+    expect(widget.__owl__.status).toBe(STATUS.DESTROYED);
   });
 
   test("destroying a parent also destroys its children", async () => {
@@ -985,9 +1044,9 @@ describe("destroy method", () => {
 
     const child = children(parent)[0];
 
-    expect(child.__owl__.isDestroyed).toBe(false);
+    expect(child.__owl__.status).toBe(STATUS.MOUNTED);
     parent.destroy();
-    expect(child.__owl__.isDestroyed).toBe(true);
+    expect(child.__owl__.status).toBe(STATUS.DESTROYED);
   });
 
   test("destroy remove the parent/children link", async () => {
@@ -1013,17 +1072,15 @@ describe("destroy method", () => {
     }
     expect(fixture.innerHTML).toBe("");
     const widget = new DelayedWidget();
+    expect(widget.__owl__.status).toBe(STATUS.CREATED);
     widget.mount(fixture);
-    expect(widget.__owl__.isMounted).toBe(false);
-    expect(widget.__owl__.isDestroyed).toBe(false);
+    expect(widget.__owl__.status).toBe(STATUS.WILLSTARTED);
     widget.destroy();
-    expect(widget.__owl__.isMounted).toBe(false);
-    expect(widget.__owl__.isDestroyed).toBe(true);
+    expect(widget.__owl__.status).toBe(STATUS.DESTROYED);
     def.resolve();
     await nextTick();
 
-    expect(widget.__owl__.isMounted).toBe(false);
-    expect(widget.__owl__.isDestroyed).toBe(true);
+    expect(widget.__owl__.status).toBe(STATUS.DESTROYED);
     expect(widget.__owl__.vnode).toBe(undefined);
     expect(fixture.innerHTML).toBe("");
     expect(isRendered).toBe(false);
@@ -1479,7 +1536,7 @@ describe("composition", () => {
     parent.state.flag = true;
     await nextTick();
     expect(children(parent)[0]).toBe(child);
-    expect(child.__owl__.isDestroyed).toBe(false);
+    expect(child.__owl__.status).toBe(STATUS.MOUNTED);
     expect(normalize(fixture.innerHTML)).toBe(
       normalize(`
       <div>
@@ -2227,9 +2284,29 @@ describe("other directives with t-component", () => {
     el.click();
     expect(steps).toEqual(["click"]);
     parent.unmount();
-    expect(child.__owl__.isMounted).toBe(false);
+    expect(child.__owl__.status).toBe(STATUS.UNMOUNTED);
     el.click();
-    expect(steps).toEqual(["click"]);
+    expect(steps).toEqual(["click", "click"]);
+  });
+
+  test("triggering custom event on mounted components", async () => {
+    let value = false;
+    class Child extends Component {
+      static template = xml`<div/>`;
+      mounted() {
+        this.trigger("coucou");
+      }
+    }
+    class Parent extends Component {
+      static template = xml`<Child t-on-coucou="doSomething"/>`;
+      static components = { Child };
+      doSomething() {
+        value = true;
+      }
+    }
+    const parent = new Parent();
+    await parent.mount(fixture);
+    expect(value).toBe(true);
   });
 
   test("t-on with .capture modifier", async () => {
@@ -2281,7 +2358,7 @@ describe("other directives with t-component", () => {
     expect(steps).toEqual(["click"]);
     parent.state.flag = false;
     await nextTick();
-    expect(child.__owl__.isDestroyed).toBe(true);
+    expect(child.__owl__.status).toBe(STATUS.DESTROYED);
     el.click();
     expect(steps).toEqual(["click"]);
   });
@@ -2316,7 +2393,7 @@ describe("other directives with t-component", () => {
     expect(steps).toEqual(["click"]);
     parent.state.flag = false;
     await nextTick();
-    expect(child.__owl__.isDestroyed).toBe(true);
+    expect(child.__owl__.status).toBe(STATUS.DESTROYED);
     el.click();
     expect(steps).toEqual(["click"]);
   });

tests/component/error_handling.test.ts

@@ -1,4 +1,4 @@
-import { Component, Env } from "../../src/component/component";
+import { Component, Env, STATUS } from "../../src/component/component";
 import { useState } from "../../src/hooks";
 import { xml } from "../../src/tags";
 import { makeTestEnv, makeTestFixture, nextTick } from "../helpers";
@@ -108,7 +108,7 @@ describe("component error handling (catchError)", () => {
 
     expect(console.error).toBeCalledTimes(0);
     console.error = consoleError;
-    expect(app.__owl__.isDestroyed).toBe(true);
+    expect(app.__owl__.status).toBe(STATUS.DESTROYED);
     expect(handler).toBeCalledTimes(1);
   });
 

tests/component/un_mounting.test.ts

@@ -323,6 +323,54 @@ describe("unmounting and remounting", () => {
     expect(steps).toEqual([2, 2, 3]);
   });
 
+  test("change state and render while mounted in detached dom", async () => {
+    class App extends Component {
+      static template = xml`<div><t t-esc="state.val"/></div>`;
+      state = useState({ val: 1 });
+    }
+
+    const detachedDiv = document.createElement("div");
+    const app = await mount(App, { target: detachedDiv });
+
+    expect(detachedDiv.innerHTML).toBe("<div>1</div>");
+    app.state.val = 2;
+    await nextTick();
+    expect(detachedDiv.innerHTML).toBe("<div>2</div>");
+  });
+
+  test("change state and render while not mounted ", async () => {
+    class App extends Component {
+      static template = xml`<div><t t-esc="state.val"/></div>`;
+      state = useState({ val: 1 });
+    }
+
+    const app = new App(null);
+
+    app.state.val = 2; // will call the render method (before being mounted)
+    await nextTick();
+
+    await app.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div>2</div>");
+  });
+
+  test("destroy and change state after mounted in detached dom", async () => {
+    class App extends Component {
+      static template = xml`<div><t t-esc="state.val"/></div>`;
+      state = useState({ val: 1 });
+    }
+
+    const detachedDiv = document.createElement("div");
+    const app = await mount(App, { target: detachedDiv });
+
+    expect(detachedDiv.innerHTML).toBe("<div>1</div>");
+
+    app.destroy();
+    app.state.val = 2;
+    await nextTick();
+    expect(detachedDiv.innerHTML).toBe("");
+  });
+
   test("change state while component is unmounted", async () => {
     let child;
     class Child extends Component {
@@ -356,6 +404,40 @@ describe("unmounting and remounting", () => {
     expect(fixture.innerHTML).toBe("<div>P2<span>C2</span></div>");
   });
 
+  test("change state while component is mounted in a fragment", async () => {
+    class Child1 extends Component {
+      static template = xml`<span>C1</span>`;
+    }
+
+    class Child2 extends Component {
+      static template = xml`<span>C2</span>`;
+    }
+
+    class Parent extends Component {
+      static components = { Child1, Child2 };
+      static template = xml`
+        <div>
+          <Child1 t-if="child == 'c1'"/>
+          <Child2 t-if="child == 'c2'"/>
+        </div>`;
+      child: string | false = false;
+    }
+
+    const fragment = document.createDocumentFragment();
+    const parent = new Parent();
+    await parent.mount(fragment);
+    expect(parent.el.outerHTML).toBe("<div></div>");
+
+    parent.child = "c1";
+    parent.render();
+    await Promise.resolve();
+
+    parent.child = "c2";
+    await parent.mount(fixture);
+
+    expect(fixture.innerHTML).toBe("<div><span>C2</span></div>");
+  });
+
   test("unmount component during a re-rendering", async () => {
     const def = makeDeferred();
     class Child extends Component {
@@ -442,17 +524,17 @@ describe("unmounting and remounting", () => {
     // one full tick.
     await nextMicroTick();
     await nextMicroTick();
-    expect(steps).toEqual(["1 catch"]);
+    expect(steps).toEqual([]);
     await nextTick();
     expect(fixture.innerHTML).toBe("<div></div><span></span>");
 
     def.resolve();
     await nextTick();
-    expect(steps).toEqual(["1 catch", "2 resolved"]);
+    expect(steps).toEqual(["2 resolved"]);
     expect(fixture.innerHTML).toBe("<div></div><span><div>Hey</div></span>");
   });
 
-  test("widget can be mounted on same target, another situation", async () => {
+  test("component can be mounted on same target, another situation", async () => {
     const def = makeDeferred();
     const steps: string[] = [];
 
@@ -480,8 +562,8 @@ describe("unmounting and remounting", () => {
 
     def.resolve();
     await nextTick();
-    expect(steps).toEqual(["1 resolved", "2 resolved"]);
     expect(fixture.innerHTML).toBe("<div>Hey</div>");
+    expect(steps).toEqual(["1 resolved", "2 resolved"]);
   });
 
   test("mounting a destroyed widget", async () => {
@@ -600,4 +682,51 @@ describe("unmounting and remounting", () => {
     await parent.render();
     expect(fixture.textContent).toBe("fixedsome text");
   });
+
+  test("remounting component tree where a component implement shouldupdate", async () => {
+    let state: any;
+    const steps = [];
+    class Child extends Component {
+      static template = xml`<div><t t-esc="state.word"/><t t-esc="props.name"/></div>`;
+
+      state = useState({ word: "hello" });
+
+      constructor(parent, props) {
+        super(parent, props);
+        state = this.state;
+      }
+      patched() {
+        steps.push("patched");
+      }
+      mounted() {
+        steps.push("mounted");
+      }
+      willUnmount() {
+        steps.push("willUnmount");
+      }
+      shouldUpdate() {
+        return false;
+      }
+    }
+
+    class Parent extends Component {
+      static template = xml`<div><Child name="state.name"/></div>`;
+      static components = { Child };
+      state = useState({ name: "World" });
+    }
+
+    const parent = await mount(Parent, { target: fixture });
+    expect(fixture.innerHTML).toBe("<div><div>helloWorld</div></div>");
+
+    parent.unmount();
+    expect(fixture.innerHTML).toBe("");
+    await parent.mount(fixture);
+    expect(fixture.innerHTML).toBe("<div><div>helloWorld</div></div>");
+
+    state.word = "test";
+
+    await nextTick();
+    expect(fixture.innerHTML).toBe("<div><div>testWorld</div></div>");
+    expect(steps).toEqual(["mounted", "willUnmount", "mounted", "patched"]);
+  });
 });

tests/context.test.ts

@@ -289,7 +289,26 @@ describe("Context", () => {
     expect(testContext.subscriptions.update.length).toBe(0);
   });
 
-  test("concurrent renderings", async () => {
+  test.skip("concurrent renderings", async () => {
+    /**
+     * Note: this test is interesting, but sadly just an incomplete attempt at
+     * protecting users against themselves.  With the context API, it is not
+     * possible for the framework to protect completely against crashes.  Maybe
+     * like in this case, when a component is in a simple hierarchy where all
+     * renderings come from the context changes, but in a real case, where some
+     * code can trigger a rendering independently, it is insufficient.
+     *
+     * The main problem is that the sub component depends on some external state,
+     * which may be modified, and then incompatible with the component actual
+     * state (for example, if the sub component has an id key related to some
+     * object that has been removed from the context).
+     *
+     * For now, sadly, the only solution is that components that depends on external
+     * state should guarantee their own integrity themselves. Then maybe this
+     * could be solved at the level of a state management solution that has a
+     * more advanced API, to let components determine if they should be updated
+     * or not (so, something slightly more advanced that the useStore hook).
+     */
     const testContext = new Context({ x: { n: 1 }, key: "x" });
     const def = makeDeferred();
     let stateC;

tests/helpers.ts

@@ -1,4 +1,4 @@
-import { Env, Component } from "../src/component/component";
+import { Env, Component, STATUS } from "../src/component/component";
 import { scheduler } from "../src/component/scheduler";
 import { EvalContext, QWeb } from "../src/qweb/qweb";
 import { CompilationContext } from "../src/qweb/compilation_context";
@@ -92,7 +92,7 @@ export function renderToDOM(
   if (!context.__owl__) {
     // we add `__owl__` to better simulate a component as context.  This is
     // particularly important for event handlers added with the `t-on` directive.
-    context.__owl__ = { isMounted: true };
+    context.__owl__ = { status: STATUS.MOUNTED };
   }
   const vnode = qweb.render(template, context, extra);
 

tests/hooks.test.ts

@@ -9,8 +9,10 @@ import {
   onWillPatch,
   onWillStart,
   onWillUpdateProps,
+  useEnv,
   useSubEnv,
   useExternalListener,
+  useComponent,
 } from "../src/hooks";
 import { xml } from "../src/tags";
 
@@ -520,6 +522,19 @@ describe("hooks", () => {
     });
   });
 
+  test("can use useEnv", async () => {
+    expect.assertions(1);
+    class TestComponent extends Component {
+      static template = xml`<div><t t-esc="env.val"/></div>`;
+      constructor() {
+        super();
+        expect(useEnv()).toBe(env);
+      }
+    }
+    const component = new TestComponent();
+    await component.mount(fixture);
+  });
+
   test("can use sub env", async () => {
     class TestComponent extends Component {
       static template = xml`<div><t t-esc="env.val"/></div>`;
@@ -535,6 +550,19 @@ describe("hooks", () => {
     expect(component.env).toHaveProperty("val");
   });
 
+  test("can use useComponent", async () => {
+    expect.assertions(1);
+    class TestComponent extends Component {
+      static template = xml`<div></div>`;
+      constructor() {
+        super();
+        expect(useComponent()).toBe(this);
+      }
+    }
+    const component = new TestComponent();
+    await component.mount(fixture);
+  });
+
   test("parent and child env", async () => {
     class Child extends Component {
       static template = xml`<div><t t-esc="env.val"/></div>`;

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

@@ -2727,7 +2727,7 @@ exports[`t-on can bind event handler 1`] = `
     let h = this.h;
     let c1 = [], p1 = {key:1,on:{}};
     let vn1 = h('button', p1, c1);
-    extra.handlers['click__2__'] = extra.handlers['click__2__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['add'](e);};
+    extra.handlers['click__2__'] = extra.handlers['click__2__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['add'](e);};
     p1.on['click'] = extra.handlers['click__2__'];
     c1.push({text: \`Click\`});
     return vn1;
@@ -2744,7 +2744,7 @@ exports[`t-on can bind handlers with arguments 1`] = `
     let c1 = [], p1 = {key:1,on:{}};
     let vn1 = h('button', p1, c1);
     let args2 = [5];
-    p1.on['click'] = function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['add'](...args2, e);};
+    p1.on['click'] = function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['add'](...args2, e);};
     c1.push({text: \`Click\`});
     return vn1;
 }"
@@ -2760,7 +2760,7 @@ exports[`t-on can bind handlers with empty object (with non empty inner string)
     let c1 = [], p1 = {key:1,on:{}};
     let vn1 = h('button', p1, c1);
     let args2 = [{}];
-    p1.on['click'] = function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['doSomething'](...args2, e);};
+    p1.on['click'] = function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['doSomething'](...args2, e);};
     c1.push({text: \`Click\`});
     return vn1;
 }"
@@ -2776,7 +2776,7 @@ exports[`t-on can bind handlers with empty object 1`] = `
     let c1 = [], p1 = {key:1,on:{}};
     let vn1 = h('button', p1, c1);
     let args2 = [{}];
-    p1.on['click'] = function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['doSomething'](...args2, e);};
+    p1.on['click'] = function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['doSomething'](...args2, e);};
     c1.push({text: \`Click\`});
     return vn1;
 }"
@@ -2815,7 +2815,7 @@ exports[`t-on can bind handlers with loop variable as argument 1`] = `
         let vn7 = h('a', p7, c7);
         c6.push(vn7);
         let args8 = [scope['action']];
-        p7.on['click'] = function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['activate'](...args8, e);};
+        p7.on['click'] = function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['activate'](...args8, e);};
         c7.push({text: \`link\`});
     }
     scope = _origScope5;
@@ -2833,7 +2833,7 @@ exports[`t-on can bind handlers with object arguments 1`] = `
     let c1 = [], p1 = {key:1,on:{}};
     let vn1 = h('button', p1, c1);
     let args2 = [{val:5}];
-    p1.on['click'] = function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['add'](...args2, e);};
+    p1.on['click'] = function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['add'](...args2, e);};
     c1.push({text: \`Click\`});
     return vn1;
 }"
@@ -2847,9 +2847,9 @@ exports[`t-on can bind two event handlers 1`] = `
     let h = this.h;
     let c1 = [], p1 = {key:1,on:{}};
     let vn1 = h('button', p1, c1);
-    extra.handlers['click__2__'] = extra.handlers['click__2__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['handleClick'](e);};
+    extra.handlers['click__2__'] = extra.handlers['click__2__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['handleClick'](e);};
     p1.on['click'] = extra.handlers['click__2__'];
-    extra.handlers['dblclick__3__'] = extra.handlers['dblclick__3__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['handleDblClick'](e);};
+    extra.handlers['dblclick__3__'] = extra.handlers['dblclick__3__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['handleDblClick'](e);};
     p1.on['dblclick'] = extra.handlers['dblclick__3__'];
     c1.push({text: \`Click\`});
     return vn1;
@@ -2864,7 +2864,7 @@ exports[`t-on handler is bound to proper owner 1`] = `
     let h = this.h;
     let c1 = [], p1 = {key:1,on:{}};
     let vn1 = h('button', p1, c1);
-    extra.handlers['click__2__'] = extra.handlers['click__2__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['add'](e);};
+    extra.handlers['click__2__'] = extra.handlers['click__2__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['add'](e);};
     p1.on['click'] = extra.handlers['click__2__'];
     c1.push({text: \`Click\`});
     return vn1;
@@ -2883,7 +2883,7 @@ exports[`t-on t-on combined with t-esc 1`] = `
     let c2 = [], p2 = {key:2,on:{}};
     let vn2 = h('button', p2, c2);
     c1.push(vn2);
-    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['onClick'](e);};
+    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['onClick'](e);};
     p2.on['click'] = extra.handlers['click__3__'];
     let _4 = scope['text'];
     if (_4 != null) {
@@ -2905,7 +2905,7 @@ exports[`t-on t-on combined with t-raw 1`] = `
     let c2 = [], p2 = {key:2,on:{}};
     let vn2 = h('button', p2, c2);
     c1.push(vn2);
-    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['onClick'](e);};
+    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['onClick'](e);};
     p2.on['click'] = extra.handlers['click__3__'];
     let _4 = scope['html'];
     if (_4 != null) {
@@ -2923,12 +2923,12 @@ exports[`t-on t-on with .capture modifier 1`] = `
     let h = this.h;
     let c1 = [], p1 = {key:1,on:{}};
     let vn1 = h('div', p1, c1);
-    extra.handlers['!click__2__'] = extra.handlers['!click__2__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['onCapture'](e);};
+    extra.handlers['!click__2__'] = extra.handlers['!click__2__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['onCapture'](e);};
     p1.on['!click'] = extra.handlers['!click__2__'];
     let c3 = [], p3 = {key:3,on:{}};
     let vn3 = h('button', p3, c3);
     c1.push(vn3);
-    extra.handlers['click__4__'] = extra.handlers['click__4__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['doSomething'](e);};
+    extra.handlers['click__4__'] = extra.handlers['click__4__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['doSomething'](e);};
     p3.on['click'] = extra.handlers['click__4__'];
     c3.push({text: \`Button\`});
     return vn1;
@@ -2946,7 +2946,7 @@ exports[`t-on t-on with empty handler (only modifiers) 1`] = `
     let c2 = [], p2 = {key:2,on:{}};
     let vn2 = h('button', p2, c2);
     c1.push(vn2);
-    p2.on['click'] = function (e) {if (!context.__owl__.isMounted){return}e.preventDefault();};
+    p2.on['click'] = function (e) {if (context.__owl__.status === 5){return}e.preventDefault();};
     c2.push({text: \`Button\`});
     return vn1;
 }"
@@ -2961,7 +2961,7 @@ exports[`t-on t-on with inline statement (function call) 1`] = `
     let c1 = [], p1 = {key:1,on:{}};
     let vn1 = h('button', p1, c1);
     const state_2 = scope['state'];
-    p1.on['click'] = function (e) {if (!context.__owl__.isMounted){return}state_2.incrementCounter(2)};
+    p1.on['click'] = function (e) {if (context.__owl__.status === 5){return}state_2.incrementCounter(2)};
     c1.push({text: \`Click\`});
     return vn1;
 }"
@@ -2976,7 +2976,7 @@ exports[`t-on t-on with inline statement 1`] = `
     let c1 = [], p1 = {key:1,on:{}};
     let vn1 = h('button', p1, c1);
     const state_2 = scope['state'];
-    p1.on['click'] = function (e) {if (!context.__owl__.isMounted){return}state_2.counter++};
+    p1.on['click'] = function (e) {if (context.__owl__.status === 5){return}state_2.counter++};
     c1.push({text: \`Click\`});
     return vn1;
 }"
@@ -2991,7 +2991,7 @@ exports[`t-on t-on with inline statement, part 2 1`] = `
     let c1 = [], p1 = {key:1,on:{}};
     let vn1 = h('button', p1, c1);
     const state_2 = scope['state'];
-    p1.on['click'] = function (e) {if (!context.__owl__.isMounted){return}state_2.flag=!state_2.flag};
+    p1.on['click'] = function (e) {if (context.__owl__.status === 5){return}state_2.flag=!state_2.flag};
     c1.push({text: \`Toggle\`});
     return vn1;
 }"
@@ -3007,7 +3007,7 @@ exports[`t-on t-on with inline statement, part 3 1`] = `
     let vn1 = h('button', p1, c1);
     const state_2 = scope['state'];
     const someFunction_2 = scope['someFunction'];
-    p1.on['click'] = function (e) {if (!context.__owl__.isMounted){return}state_2.n=someFunction_2(3)};
+    p1.on['click'] = function (e) {if (context.__owl__.status === 5){return}state_2.n=someFunction_2(3)};
     c1.push({text: \`Toggle\`});
     return vn1;
 }"
@@ -3024,7 +3024,7 @@ exports[`t-on t-on with prevent and self modifiers (order matters) 1`] = `
     let c2 = [], p2 = {key:2,on:{}};
     let vn2 = h('button', p2, c2);
     c1.push(vn2);
-    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (!context.__owl__.isMounted){return}e.preventDefault();if (e.target !== this.elm) {return}utils.getComponent(context)['onClick'](e);};
+    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (context.__owl__.status === 5){return}e.preventDefault();if (e.target !== this.elm) {return}utils.getComponent(context)['onClick'](e);};
     p2.on['click'] = extra.handlers['click__3__'];
     let c4 = [], p4 = {key:4};
     let vn4 = h('span', p4, c4);
@@ -3045,19 +3045,19 @@ exports[`t-on t-on with prevent and/or stop modifiers 1`] = `
     let c2 = [], p2 = {key:2,on:{}};
     let vn2 = h('button', p2, c2);
     c1.push(vn2);
-    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (!context.__owl__.isMounted){return}e.preventDefault();utils.getComponent(context)['onClickPrevented'](e);};
+    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (context.__owl__.status === 5){return}e.preventDefault();utils.getComponent(context)['onClickPrevented'](e);};
     p2.on['click'] = extra.handlers['click__3__'];
     c2.push({text: \`Button 1\`});
     let c4 = [], p4 = {key:4,on:{}};
     let vn4 = h('button', p4, c4);
     c1.push(vn4);
-    extra.handlers['click__5__'] = extra.handlers['click__5__'] || function (e) {if (!context.__owl__.isMounted){return}e.stopPropagation();utils.getComponent(context)['onClickStopped'](e);};
+    extra.handlers['click__5__'] = extra.handlers['click__5__'] || function (e) {if (context.__owl__.status === 5){return}e.stopPropagation();utils.getComponent(context)['onClickStopped'](e);};
     p4.on['click'] = extra.handlers['click__5__'];
     c4.push({text: \`Button 2\`});
     let c6 = [], p6 = {key:6,on:{}};
     let vn6 = h('button', p6, c6);
     c1.push(vn6);
-    extra.handlers['click__7__'] = extra.handlers['click__7__'] || function (e) {if (!context.__owl__.isMounted){return}e.preventDefault();e.stopPropagation();utils.getComponent(context)['onClickPreventedAndStopped'](e);};
+    extra.handlers['click__7__'] = extra.handlers['click__7__'] || function (e) {if (context.__owl__.status === 5){return}e.preventDefault();e.stopPropagation();utils.getComponent(context)['onClickPreventedAndStopped'](e);};
     p6.on['click'] = extra.handlers['click__7__'];
     c6.push({text: \`Button 3\`});
     return vn1;
@@ -3097,7 +3097,7 @@ exports[`t-on t-on with prevent modifier in t-foreach 1`] = `
             let vn7 = h('a', p7, c7);
             c1.push(vn7);
             let args8 = [scope['project'].id];
-            p7.on['click'] = function (e) {if (!context.__owl__.isMounted){return}e.preventDefault();utils.getComponent(context)['onEdit'](...args8, e);};
+            p7.on['click'] = function (e) {if (context.__owl__.status === 5){return}e.preventDefault();utils.getComponent(context)['onEdit'](...args8, e);};
             c7.push({text: \` Edit \`});
             let _9 = scope['project'].name;
             if (_9 != null) {
@@ -3121,7 +3121,7 @@ exports[`t-on t-on with self and prevent modifiers (order matters) 1`] = `
     let c2 = [], p2 = {key:2,on:{}};
     let vn2 = h('button', p2, c2);
     c1.push(vn2);
-    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (!context.__owl__.isMounted){return}if (e.target !== this.elm) {return}e.preventDefault();utils.getComponent(context)['onClick'](e);};
+    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (context.__owl__.status === 5){return}if (e.target !== this.elm) {return}e.preventDefault();utils.getComponent(context)['onClick'](e);};
     p2.on['click'] = extra.handlers['click__3__'];
     let c4 = [], p4 = {key:4};
     let vn4 = h('span', p4, c4);
@@ -3142,7 +3142,7 @@ exports[`t-on t-on with self modifier 1`] = `
     let c2 = [], p2 = {key:2,on:{}};
     let vn2 = h('button', p2, c2);
     c1.push(vn2);
-    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['onClick'](e);};
+    extra.handlers['click__3__'] = extra.handlers['click__3__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['onClick'](e);};
     p2.on['click'] = extra.handlers['click__3__'];
     let c4 = [], p4 = {key:4};
     let vn4 = h('span', p4, c4);
@@ -3151,7 +3151,7 @@ exports[`t-on t-on with self modifier 1`] = `
     let c5 = [], p5 = {key:5,on:{}};
     let vn5 = h('button', p5, c5);
     c1.push(vn5);
-    extra.handlers['click__6__'] = extra.handlers['click__6__'] || function (e) {if (!context.__owl__.isMounted){return}if (e.target !== this.elm) {return}utils.getComponent(context)['onClickSelf'](e);};
+    extra.handlers['click__6__'] = extra.handlers['click__6__'] || function (e) {if (context.__owl__.status === 5){return}if (e.target !== this.elm) {return}utils.getComponent(context)['onClickSelf'](e);};
     p5.on['click'] = extra.handlers['click__6__'];
     let c7 = [], p7 = {key:7};
     let vn7 = h('span', p7, c7);
@@ -3924,6 +3924,18 @@ exports[`translation support some attributes are translated 1`] = `
 }"
 `;
 
+exports[`translation support translation is done on the trimmed text, with extra spaces readded after 1`] = `
+"function anonymous(context, extra
+) {
+    // Template name: \\"test\\"
+    let h = this.h;
+    let c1 = [], p1 = {key:1};
+    let vn1 = h('div', p1, c1);
+    c1.push({text: \` mot \`});
+    return vn1;
+}"
+`;
+
 exports[`whitespace handling consecutives whitespaces are condensed into a single space 1`] = `
 "function anonymous(context, extra
 ) {

tests/qweb/qweb.test.ts

@@ -2154,6 +2154,17 @@ describe("translation support", () => {
       '<div><p label="mot">mot</p><p title="mot">mot</p><p placeholder="mot">mot</p><p alt="mot">mot</p><p something="word">mot</p></div>'
     );
   });
+
+  test("translation is done on the trimmed text, with extra spaces readded after", () => {
+    const translations = {
+      word: "mot",
+    };
+    const translateFn = jest.fn((expr) => translations[expr] || expr);
+    const qweb = new QWeb({ translateFn });
+    qweb.addTemplate("test", "<div> word </div>");
+    expect(renderToString(qweb, "test")).toBe("<div> mot </div>");
+    expect(translateFn).toHaveBeenCalledWith("word");
+  });
 });
 
 describe("t-key tests", () => {

tests/qweb/qweb_expressions.test.ts

@@ -196,4 +196,8 @@ describe("expression evaluation", () => {
     expect(compileExpr("f(...state.list)", {})).toBe("scope['f'](...scope['state'].list)");
     expect(compileExpr("f([...list])", {})).toBe("scope['f']([...scope['list']])");
   });
+
+  test("works with builtin properties", () => {
+    expect(compileExpr("state.constructor.name", {})).toBe("scope['state'].constructor.name");
+  });
 });

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

@@ -11,7 +11,7 @@ exports[`Link component can render simple cases 1`] = `
     let _6 = scope['href'];
     let c7 = [], p7 = {key:7,attrs:{href: _6},class:_5,on:{}};
     let vn7 = h('a', p7, c7);
-    extra.handlers['click__8__'] = extra.handlers['click__8__'] || function (e) {if (!context.__owl__.isMounted){return}utils.getComponent(context)['navigate'](e);};
+    extra.handlers['click__8__'] = extra.handlers['click__8__'] || function (e) {if (context.__owl__.status === 5){return}utils.getComponent(context)['navigate'](e);};
     p7.on['click'] = extra.handlers['click__8__'];
     const slot9 = this.constructor.slots[context.__owl__.slotId + '_' + 'default'];
     if (slot9) {

tests/store_hooks.test.ts

@@ -1,4 +1,4 @@
-import { Component, Env } from "../src/component/component";
+import { Component, Env, mount } from "../src/component/component";
 import { Store, useStore, useDispatch, useGetters, EnvWithStore } from "../src/store";
 import { useState } from "../src/hooks";
 import { xml } from "../src/tags";
@@ -571,12 +571,12 @@ describe("connecting a component to store", () => {
     app.state.beerId = 2;
     await nextTick();
     expect(fixture.innerHTML).toBe("<div><span>kwak</span></div>");
-    expect(counter).toBe(1);
+    expect(counter).toBe(0);
 
     store.dispatch("renameBeer", { id: 2, name: "orval" });
     await nextTick();
     expect(fixture.innerHTML).toBe("<div><span>orval</span></div>");
-    expect(counter).toBe(2);
+    expect(counter).toBe(1);
   });
 
   test("connected component is properly cleaned up on destroy", async () => {
@@ -1241,4 +1241,162 @@ describe("various scenarios", () => {
     await nextTick();
     expect(fixture.innerHTML).toMatchSnapshot();
   });
+
+  test("component with store, useState and shouldUpdate=false", async () => {
+    let state: any;
+
+    const store = new Store({ state: { rev: 0 } });
+
+    class Child extends Component {
+      static template = xml`<div><t t-esc="state.word"/><t t-esc="props.name"/></div>`;
+
+      state = useState({ word: "hello" });
+
+      constructor(parent, props) {
+        super(parent, props);
+        state = this.state;
+        useStore((props) => {
+          return 1;
+        });
+      }
+
+      shouldUpdate() {
+        return false;
+      }
+    }
+
+    class Parent extends Component {
+      static template = xml`<div><Child name="state.name"/></div>`;
+      static components = { Child };
+
+      state = useState({ name: "World" });
+
+      constructor(parent, props) {
+        super(parent, props);
+        useStore((props) => store.state.rev);
+      }
+    }
+    (env as any).store = store;
+
+    await mount(Parent, { target: fixture, env });
+    expect(fixture.innerHTML).toBe("<div><div>helloWorld</div></div>");
+
+    store.state.rev++;
+    // this is the key to the bug, it makes Parent be in "render" state but not
+    // yet rendered while the change of state happens
+    await Promise.resolve();
+    state.word = "test";
+    await nextTick();
+    expect(fixture.innerHTML).toBe("<div><div>testWorld</div></div>");
+  });
+
+  test("component with store, useState, shouldUpdate=false and child with shouldupdate false", async () => {
+    let state: any;
+
+    const store = new Store({ state: { rev: 0 } });
+
+    class ChildChild extends Component {
+      static template = xml`<div><t t-esc="props.value"/></div>`;
+
+      shouldUpdate() {
+        return false;
+      }
+    }
+
+    class Child extends Component {
+      static template = xml`<div><t t-esc="state.word"/><t t-esc="props.name"/><ChildChild value="state.value"/></div>`;
+      static components = { ChildChild };
+      state = useState({ word: "hello", value: 3 });
+
+      constructor(parent, props) {
+        super(parent, props);
+        state = this.state;
+        useStore((props) => {
+          return 1;
+        });
+      }
+
+      shouldUpdate() {
+        return false;
+      }
+    }
+
+    class Parent extends Component {
+      static template = xml`<div><Child name="state.name"/></div>`;
+      static components = { Child };
+
+      state = useState({ name: "World" });
+      constructor(parent, props) {
+        super(parent, props);
+        useStore((props) => store.state.rev);
+      }
+    }
+    (env as any).store = store;
+
+    await mount(Parent, { target: fixture, env });
+    expect(fixture.innerHTML).toBe("<div><div>helloWorld<div>3</div></div></div>");
+
+    store.state.rev++;
+    // this is the key to the bug, it makes Parent be in "render" state but not
+    // yet rendered while the change of state happens
+    await Promise.resolve();
+    state.word = "test";
+    state.value = 44;
+    await nextTick();
+    expect(fixture.innerHTML).toBe("<div><div>testWorld<div>3</div></div></div>");
+  });
+
+  test("parent/children with store, parent is remounted", async () => {
+    const store = new Store({ state: { a: 1, b: 1 } });
+
+    class Child extends Component {
+      static template = xml`<div><t t-esc="a"/></div>`;
+      a: any;
+      constructor(parent, props) {
+        super(parent, props);
+        this.a = useStore(
+          (state, props) => {
+            return state.a;
+          },
+          {
+            onUpdate: (a) => {
+              this.a = a;
+            },
+          }
+        );
+      }
+    }
+
+    class Parent extends Component {
+      static template = xml`
+        <div>
+          parent: <t t-esc="b"/>
+          <Child/>
+        </div>`;
+      static components = { Child };
+
+      b: any;
+      constructor(parent, props) {
+        super(parent, props);
+        this.b = useStore((state, props) => {
+          return state.b;
+        });
+      }
+    }
+    (env as any).store = store;
+
+    const div = document.createElement("div");
+    fixture.appendChild(div);
+
+    // initial mounting
+    const parent = await mount(Parent, { target: fixture, env });
+    expect(fixture.innerHTML).toBe("<div></div><div> parent: 1<div>1</div></div>");
+
+    // remounting component, then immediately update store.state
+    parent.mount(div);
+    store.state.a++;
+
+    await nextTick();
+    expect(fixture.innerHTML).toBe("<div><div> parent: 1<div>2</div></div></div>");
+  });
 });

tests/tooling/debug_script_3.test.ts

@@ -8,7 +8,7 @@ import * as owl from "../../src/index";
 
 import { Component, Env } from "../../src/component/component";
 import { xml } from "../../src/tags";
-import { makeTestFixture, makeTestEnv } from "../helpers";
+import { makeTestFixture, makeTestEnv, nextTick } from "../helpers";
 
 let fixture: HTMLElement = makeTestFixture();
 let env: Env = makeTestEnv();
@@ -31,6 +31,7 @@ test("log a specific message for render method calls if component is not mounted
   parent.unmount();
   parent.state.value = 2;
 
+  await nextTick();
   expect(steps).toEqual([
     "[OWL_DEBUG] Parent<id=1> constructor, props={}",
     "[OWL_DEBUG] Parent<id=1> mount",
@@ -40,7 +41,10 @@ test("log a specific message for render method calls if component is not mounted
     "[OWL_DEBUG] Parent<id=1> mounted",
     "[OWL_DEBUG] scheduler: stop running tasks queue",
     "[OWL_DEBUG] Parent<id=1> willUnmount",
-    "[OWL_DEBUG] Parent<id=1> render (warning: component is not mounted, this render has no effect)",
+    "[OWL_DEBUG] Parent<id=1> render (warning: component is not mounted)",
+    "[OWL_DEBUG] scheduler: start running tasks queue",
+    "[OWL_DEBUG] Parent<id=1> rendering template",
+    "[OWL_DEBUG] scheduler: stop running tasks queue",
   ]);
   console.log = log;
 });

tools/debug.js

@@ -101,8 +101,8 @@
     component.render = function(...args) {
       const __owl__ = component.__owl__;
       let msg = `render`;
-      if (!__owl__.isMounted && !__owl__.currentFiber) {
-        msg += ` (warning: component is not mounted, this render has no effect)`;
+      if (__owl__.status !== 3 /* mounted */ && !__owl__.currentFiber) {
+        msg += ` (warning: component is not mounted)`;
       }
       log(msg);
       return render(...args);

tools/playground/samples.js

@@ -2,8 +2,7 @@ const COMPONENTS = `// In this example, we show how components can be defined an
 const { Component, useState, mount } = owl;
 
 class Greeter extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.state = useState({ word: 'Hello' });
     }
 
@@ -14,10 +13,9 @@ class Greeter extends Component {
 
 // Main root component
 class App extends Component {
-    constructor() {
-        super(...arguments);
-        this.state = useState({ name: 'World'});
-    }
+  setup() {
+    this.state = useState({ name: 'World'});
+  }
 }
 App.components = { Greeter };
 
@@ -52,8 +50,7 @@ const ANIMATION = `// The goal of this component is to see how the t-transition
 const { Component, useState, mount } = owl;
 
 class Counter extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.state = useState({ value: 0 });
     }
 
@@ -63,8 +60,7 @@ class Counter extends Component {
 }
 
 class App extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.state = useState({ flag: false, componentFlag: false, numbers: [] });
     }
 
@@ -194,10 +190,9 @@ const LIFECYCLE_DEMO = `// This example shows all the possible lifecycle hooks
 const { Component, useState, mount } = owl;
 
 class DemoComponent extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.state = useState({ n: 0 });
-        console.log("constructor");
+        console.log("setup");
     }
     async willStart() {
         console.log("willstart");
@@ -223,8 +218,7 @@ class DemoComponent extends Component {
 }
 
 class App extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.state = useState({ n: 0, flag: true });
     }
 
@@ -295,8 +289,7 @@ function useMouse() {
 
 // Main root component
 class App extends owl.Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         // simple state hook (reactive object)
         this.counter = useState({ value: 0 });
 
@@ -333,8 +326,7 @@ const { Component, Context, mount } = owl;
 const { useContext } = owl.hooks;
 
 class ToolbarButton extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.theme = useContext(this.env.themeContext);
     }
 
@@ -468,8 +460,7 @@ const actions = {
 // TodoItem
 //------------------------------------------------------------------------------
 class TodoItem extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         useAutofocus("input");
         this.state = useState({ isEditing: false });
         this.dispatch = useDispatch();
@@ -499,8 +490,7 @@ class TodoItem extends Component {
 // TodoApp
 //------------------------------------------------------------------------------
 class TodoApp extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.state = useState({ filter: "all" });
         this.todos = useStore(state => state.todos);
         this.dispatch = useDispatch();
@@ -1026,8 +1016,7 @@ class FormView extends owl.Component {}
 FormView.components = { AdvancedComponent };
 
 class Chatter extends owl.Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.messages = Array.from(Array(100).keys());
     }
 }
@@ -1170,8 +1159,7 @@ const SLOTS = `// We show here how slots can be used to create generic component
 const { Component, useState, mount } = owl;
 
 class Card extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.state = useState({ showContent: true });
     }
 
@@ -1181,8 +1169,7 @@ class Card extends Component {
 }
 
 class Counter extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.state = useState({val: 1});
     }
 
@@ -1193,8 +1180,7 @@ class Counter extends Component {
 
 // Main root component
 class App extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.state = useState({a: 1, b: 3});
     }
 
@@ -1306,8 +1292,7 @@ class SlowComponent extends Component {
 class NotificationList extends Component {}
 
 class App extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.state = useState({ value: 0, notifs: [] });
     }
 
@@ -1381,8 +1366,7 @@ const FORM = `// This example illustrate how the t-model directive can be used t
 const { Component, useState, mount } = owl;
 
 class Form extends Component {
-    constructor() {
-        super(...arguments);
+    setup() {
         this.state = useState({
             text: "",
             othertext: "",
@@ -1556,8 +1540,7 @@ const { useRef } = owl.hooks;
 class HelloWorld extends Component {}
 
 class Counter extends Component {
-  constructor() {
-    super(...arguments);
+  setup() {
     this.state = useState({ value: 0 });
   }
 
@@ -1610,8 +1593,7 @@ class Window extends Component {
 }
 
 class WindowManager extends Component {
-  constructor() {
-    super(...arguments);
+  setup() {
     this.windows = [];
     this.nextId = 1;
     this.currentZindex = 1;
@@ -1661,8 +1643,7 @@ class WindowManager extends Component {
 WindowManager.components = { Window };
 
 class App extends Component {
-  constructor() {
-    super(...arguments);
+  setup() {
     this.wmRef = useRef("wm");
   }