From 6ae92fa4b3690c815d3ae28b0f86f4410547b77e Mon Sep 17 00:00:00 2001
From: Bruno Boi <boi@odoo.com>
Date: Mon, 15 Nov 2021 15:05:44 +0100
Subject: [PATCH] [IMP] hooks: reintroduce useExternalListener

---
 src/hooks.ts                                  | 29 +++++++++++++++++
 src/index.ts                                  |  2 +-
 .../__snapshots__/hooks.test.ts.snap          | 31 +++++++++++++++++++
 tests/components/hooks.test.ts                | 23 +++++++-------
 4 files changed, 73 insertions(+), 12 deletions(-)

diff --git a/src/hooks.ts b/src/hooks.ts
index 07b34360..79e8f84f 100644
--- a/src/hooks.ts
+++ b/src/hooks.ts
@@ -90,3 +90,32 @@ export function useEffect(effect: Effect, computeDependencies: () => any[] = ()
 
   onWillUnmount(() => cleanup());
 }
+
+// -----------------------------------------------------------------------------
+// useExternalListener
+// -----------------------------------------------------------------------------
+
+/**
+ * When a component needs to listen to DOM Events on element(s) that are not
+ * part of his hierarchy, we can use the `useExternalListener` hook.
+ * It will correctly add and remove the event listener, whenever the
+ * component is mounted and unmounted.
+ *
+ * Example:
+ *  a menu needs to listen to the click on window to be closed automatically
+ *
+ * Usage:
+ *  in the constructor of the OWL component that needs to be notified,
+ *  `useExternalListener(window, 'click', this._doSomething);`
+ * */
+export function useExternalListener(
+  target: HTMLElement | typeof window,
+  eventName: string,
+  handler: EventListener,
+  eventParams?: AddEventListenerOptions
+) {
+  const node = getCurrent()!;
+  const boundHandler = handler.bind(node.component);
+  onMounted(() => target.addEventListener(eventName, boundHandler, eventParams));
+  onWillUnmount(() => target.removeEventListener(eventName, boundHandler, eventParams));
+}
diff --git a/src/index.ts b/src/index.ts
index a7ac8a97..e46bf8ac 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -57,7 +57,7 @@ export { Portal } from "./misc/portal";
 export { Memo } from "./misc/memo";
 export { css, xml } from "./tags";
 export { useState } from "./reactivity";
-export { useRef, useEnv, useSubEnv, useEffect } from "./hooks";
+export { useEffect, useEnv, useExternalListener, useRef, useSubEnv } from "./hooks";
 export const utils = { EventBus, whenReady, loadFile };
 
 export {
diff --git a/tests/components/__snapshots__/hooks.test.ts.snap b/tests/components/__snapshots__/hooks.test.ts.snap
index 16f52263..d7cdad79 100644
--- a/tests/components/__snapshots__/hooks.test.ts.snap
+++ b/tests/components/__snapshots__/hooks.test.ts.snap
@@ -212,6 +212,37 @@ exports[`hooks useEffect hook effect with empty dependency list never reruns 1`]
 }"
 `;
 
+exports[`hooks useExternalListener 1`] = `
+"function anonymous(bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, component } = bdom;
+  let { withDefault, getTemplate, prepareList, withKey, zero, call, callSlot, capture, isBoundary, shallowEqual, setContextValue, toNumber } = helpers;
+  
+  let block1 = createBlock(\`<span><block-text-0/></span>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let d1 = ctx['props'].value;
+    return block1([d1]);
+  }
+}"
+`;
+
+exports[`hooks useExternalListener 2`] = `
+"function anonymous(bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, component } = bdom;
+  let { withDefault, getTemplate, prepareList, withKey, zero, call, callSlot, capture, isBoundary, shallowEqual, setContextValue, toNumber } = helpers;
+  
+  return function template(ctx, node, key = \\"\\") {
+    let b2;
+    if (ctx['state'].flag) {
+      b2 = component(\`MyComponent\`, {}, key + \`__1\`, node, ctx);
+    }
+    return multi([b2]);
+  }
+}"
+`;
+
 exports[`hooks useRef hook: basic use 1`] = `
 "function anonymous(bdom, helpers
 ) {
diff --git a/tests/components/hooks.test.ts b/tests/components/hooks.test.ts
index 45494d23..c2acef96 100644
--- a/tests/components/hooks.test.ts
+++ b/tests/components/hooks.test.ts
@@ -2,19 +2,20 @@ import {
   App,
   Component,
   mount,
-  useRef,
-  useState,
-  useComponent,
-  useEnv,
-  useSubEnv,
-  useEffect,
   onMounted,
   onPatched,
-  onWillStart,
-  onWillUpdateProps,
   onWillPatch,
-  xml,
+  onWillStart,
   onWillUnmount,
+  onWillUpdateProps,
+  useComponent,
+  useEffect,
+  useEnv,
+  useExternalListener,
+  useRef,
+  useState,
+  useSubEnv,
+  xml,
 } from "../../src/index";
 import { makeTestFixture, nextTick, snapshotEverything } from "../helpers";
 
@@ -287,13 +288,13 @@ describe("hooks", () => {
     ]);
   });
 
-  test.skip("useExternalListener", async () => {
+  test("useExternalListener", async () => {
     let n = 0;
 
     class MyComponent extends Component {
       static template = xml`<span><t t-esc="props.value"/></span>`;
       setup() {
-        //useExternalListener(window as any, "click", this.increment);
+        useExternalListener(window, "click", this.increment);
       }
       increment() {
         n++;