From d54cfd8a7946f9fd50f10ce0c0a0ba2ab4da1727 Mon Sep 17 00:00:00 2001
From: Christoph Reiter <reiter.christoph@gmail.com>
Date: Tue, 23 Jun 2020 14:41:47 +0200
Subject: [PATCH] Remove old event bus implementation
---
packages/common/events.js | 149 ---------------------------------
packages/common/test/events.js | 76 -----------------
2 files changed, 225 deletions(-)
delete mode 100644 packages/common/events.js
delete mode 100644 packages/common/test/events.js
diff --git a/packages/common/events.js b/packages/common/events.js
deleted file mode 100644
index fdda0b18..00000000
--- a/packages/common/events.js
+++ /dev/null
@@ -1,149 +0,0 @@
-export class EventSubscriber {
-
- /**
- * @param {string} eventName The event name used for broadcasting the event
- * @param {string} requestName The event name used for requesting the event
- */
- constructor(eventName, requestName) {
- this._eventName = eventName;
- this._requestName = requestName;
- this._callbacks = [];
- this._eventHandler = this._eventHandler.bind(this);
- }
-
- /**
- * Register a callback for the event
- *
- * @param {Function} callback
- */
- subscribe(callback) {
- const first = (this._callbacks.length === 0);
- this._callbacks.push(callback);
- if (first) {
- window.addEventListener(this._eventName, this._eventHandler);
- }
- this._requestUpdate(callback);
- }
-
- /**
- * Unregister a callback registered through subscribe()
- *
- * @param {Function} callback
- */
- unsubscribe(callback) {
- const index = this._callbacks.indexOf(callback);
- if (index == -1)
- throw new Error("not subscribed");
- this._callbacks.splice(index, 1);
- const last = (this._callbacks.length === 0);
- if (last) {
- window.removeEventListener(this._eventName, this._eventHandler);
- }
- }
-
- /**
- * Request an event, might not do anything if there is no emitter.
- */
- requestUpdate() {
- this._requestUpdate((data) => {
- for (const cb of this._callbacks) {
- cb(data);
- }
- });
- }
-
- /**
- * Returns the event data or throws an error if there is no emitter
- */
- async requestData() {
- return new Promise((resolve, reject) => {
- const event = new CustomEvent(this._requestName, {
- bubbles: true,
- composed: true,
- cancelable: true,
- detail: {'callback': resolve}
- });
- if (window.dispatchEvent(event)) {
- reject(new Error("other side not there"));
- }
- });
- }
-
- _requestUpdate(callback) {
- const event = new CustomEvent(this._requestName, {
- bubbles: true,
- composed: true,
- detail: {callback: callback}
- });
- window.dispatchEvent(event);
- }
-
- _eventHandler(event) {
- const data = event.detail.data;
- for (const cb of this._callbacks) {
- cb(data);
- }
- }
-}
-
-export class EventEmitter {
-
- /**
- * @param {string} eventName The event name used for broadcasting the event
- * @param {string} requestName The event name used for requesting the event
- */
- constructor(eventName, requestName) {
- this._eventName = eventName;
- this._requestName = requestName;
- }
-
- /**
- * Register a callback that will be called when a new event is generated.
- * The callback needs to return an object that is send with the event.
- *
- * @param {Function} callback
- */
- registerCallback(callback) {
- if (this._getData !== undefined)
- throw new Error("already registered");
- this._getData = callback;
- this._onRequest = (event) => {
- const callback = event.detail.callback;
- if (callback === undefined) {
- return;
- }
- event.preventDefault();
- event.stopImmediatePropagation();
- callback(this._getData());
- };
- window.addEventListener(this._requestName, this._onRequest);
- this.emit();
- }
-
- /**
- * Unregister a callback that was passed to registerCallback()
- *
- * @param {Function} callback
- */
- unregisterCallback(callback) {
- if (this._getData !== callback)
- throw new Error("not registered");
- window.removeEventListener(this._requestName, this._onRequest);
- delete this._getData;
- delete this._onRequest;
- }
-
- /**
- * Force emit an event (when something has changed and new data needs to be send out)
- */
- emit() {
- if (this._getData === undefined)
- throw new Error("no callback registered");
- const event = new CustomEvent(this._eventName, {
- bubbles: true,
- composed: true,
- detail: { data: this._getData() }
- });
- window.dispatchEvent(event);
- }
-}
\ No newline at end of file
diff --git a/packages/common/test/events.js b/packages/common/test/events.js
deleted file mode 100644
index 25933976..00000000
--- a/packages/common/test/events.js
+++ /dev/null
@@ -1,76 +0,0 @@
-import {assert} from 'chai';
-import {EventEmitter, EventSubscriber} from '../events.js';
-
-
-const assertThrowsAsync = async (fn, ...args) => {
- let error;
- try {
- await fn();
- } catch (e) {
- error = e;
- }
-
- return assert.throws(() => {
- if (error !== undefined)
- throw error;
- }, ...args);
-};
-
-
-suite('events', () => {
- test('emitter basics', () => {
- const ev = new EventEmitter("foo", "foo-req");
- assert.throws(ev.emit);
-
- const cb = () => { return 42; };
- ev.registerCallback(cb);
- ev.emit();
- ev.unregisterCallback(cb);
- assert.throws(() => {ev.unregisterCallback(cb);});
- assert.throws(ev.emit);
- });
-
- test('sub basics', async () => {
- const sub = new EventSubscriber("foo", "foo-req");
- await assertThrowsAsync(async () => { await sub.requestData();}, /not there/);
-
- const buffer = [];
- const handler = (data) => {
- buffer.push(data);
- };
- sub.subscribe(handler);
- sub.subscribe(handler);
- sub.requestUpdate();
- sub.unsubscribe(handler);
- sub.unsubscribe(handler);
- assert.throws(() => {sub.unsubscribe(handler);});
- assert.deepEqual(buffer, []);
- });
-
- test('both basics', async () => {
- const sub = new EventSubscriber("foo", "foo-req");
- const ev = new EventEmitter("foo", "foo-req");
- let i = 0;
- const cb = () => { return i++; };
- ev.registerCallback(cb);
-
- const buffer = [];
- const handler = (data) => {
- buffer.push(data);
- };
-
- sub.subscribe(handler);
- assert.deepEqual(buffer, [1]);
- sub.requestUpdate();
- assert.deepEqual(buffer, [1, 2]);
- sub.requestUpdate();
- assert.deepEqual(buffer, [1, 2, 3]);
- ev.emit();
- assert.deepEqual(buffer, [1, 2, 3, 4]);
-
- sub.unsubscribe(handler);
- sub.requestUpdate();
- assert.deepEqual(buffer, [1, 2, 3, 4]);
- ev.unregisterCallback(cb);
- });
-});
--
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