feat(platform-browser): allow lazy-loading HammerJS (#23906)
PR Close #23906
This commit is contained in:
Jeremy Elbourn
Alex Rickabaugh
parent
5cf82f8f3f
commit
313bdce590
@ -6,7 +6,7 @@
|
||||
* found in the LICENSE file at https://angular.io/license
|
||||
*/
|
||||
|
||||
import {Inject, Injectable, InjectionToken, ɵConsole as Console} from '@angular/core';
|
||||
import {Inject, Injectable, InjectionToken, Optional, ɵConsole as Console} from '@angular/core';
|
||||
|
||||
import {DOCUMENT} from '../dom_tokens';
|
||||
|
||||
@ -58,6 +58,13 @@ const EVENT_NAMES = {
|
||||
*/
|
||||
export const HAMMER_GESTURE_CONFIG = new InjectionToken<HammerGestureConfig>('HammerGestureConfig');
|
||||
|
||||
|
||||
/** Function that loads HammerJS, returning a promise that is resolved once HammerJs is loaded. */
|
||||
export type HammerLoader = (() => Promise<void>) | null;
|
||||
|
||||
/** Injection token used to provide a {@link HammerLoader} to Angular. */
|
||||
export const HAMMER_LOADER = new InjectionToken<HammerLoader>('HammerLoader');
|
||||
|
||||
export interface HammerInstance {
|
||||
on(eventName: string, callback?: Function): void;
|
||||
off(eventName: string, callback?: Function): void;
|
||||
@ -99,8 +106,8 @@ export class HammerGestureConfig {
|
||||
export class HammerGesturesPlugin extends EventManagerPlugin {
|
||||
constructor(
|
||||
@Inject(DOCUMENT) doc: any,
|
||||
@Inject(HAMMER_GESTURE_CONFIG) private _config: HammerGestureConfig,
|
||||
private console: Console) {
|
||||
@Inject(HAMMER_GESTURE_CONFIG) private _config: HammerGestureConfig, private console: Console,
|
||||
@Optional() @Inject(HAMMER_LOADER) private loader?: HammerLoader) {
|
||||
super(doc);
|
||||
}
|
||||
|
||||
@ -109,8 +116,10 @@ export class HammerGesturesPlugin extends EventManagerPlugin {
|
||||
return false;
|
||||
}
|
||||
|
||||
if (!(window as any).Hammer) {
|
||||
this.console.warn(`Hammer.js is not loaded, can not bind '${eventName}' event.`);
|
||||
if (!(window as any).Hammer && !this.loader) {
|
||||
this.console.warn(
|
||||
`The "${eventName}" event cannot be bound because Hammer.JS is not ` +
|
||||
`loaded and no custom loader has been specified.`);
|
||||
return false;
|
||||
}
|
||||
|
||||
@ -121,6 +130,44 @@ export class HammerGesturesPlugin extends EventManagerPlugin {
|
||||
const zone = this.manager.getZone();
|
||||
eventName = eventName.toLowerCase();
|
||||
|
||||
// If Hammer is not present but a loader is specified, we defer adding the event listener
|
||||
// until Hammer is loaded.
|
||||
if (!(window as any).Hammer && this.loader) {
|
||||
// This `addEventListener` method returns a function to remove the added listener.
|
||||
// Until Hammer is loaded, the returned function needs to *cancel* the registration rather
|
||||
// than remove anything.
|
||||
let cancelRegistration = false;
|
||||
let deregister: Function = () => { cancelRegistration = true; };
|
||||
|
||||
this.loader()
|
||||
.then(() => {
|
||||
// If Hammer isn't actually loaded when the custom loader resolves, give up.
|
||||
if (!(window as any).Hammer) {
|
||||
this.console.warn(
|
||||
`The custom HAMMER_LOADER completed, but Hammer.JS is not present.`);
|
||||
deregister = () => {};
|
||||
return;
|
||||
}
|
||||
|
||||
if (!cancelRegistration) {
|
||||
// Now that Hammer is loaded and the listener is being loaded for real,
|
||||
// the deregistration function changes from canceling registration to removal.
|
||||
deregister = this.addEventListener(element, eventName, handler);
|
||||
}
|
||||
})
|
||||
.catch(() => {
|
||||
this.console.warn(
|
||||
`The "${eventName}" event cannot be bound because the custom ` +
|
||||
`Hammer.JS loader failed.`);
|
||||
deregister = () => {};
|
||||
});
|
||||
|
||||
// Return a function that *executes* `deregister` (and not `deregister` itself) so that we
|
||||
// can change the behavior of `deregister` once the listener is added. Using a closure in
|
||||
// this way allows us to avoid any additional data structures to track listener removal.
|
||||
return () => { deregister(); };
|
||||
}
|
||||
|
||||
return zone.runOutsideAngular(() => {
|
||||
// Creating the manager bind events, must be done outside of angular
|
||||
const mc = this._config.buildHammer(element);
|
||||
|
||||
@ -5,32 +5,150 @@
|
||||
* Use of this source code is governed by an MIT-style license that can be
|
||||
* found in the LICENSE file at https://angular.io/license
|
||||
*/
|
||||
import {describe, expect, it} from '@angular/core/testing/src/testing_internal';
|
||||
import {HammerGestureConfig, HammerGesturesPlugin} from '@angular/platform-browser/src/dom/events/hammer_gestures';
|
||||
import {NgZone} from '@angular/core';
|
||||
import {fakeAsync, inject, tick} from '@angular/core/testing';
|
||||
import {afterEach, beforeEach, describe, expect, it,} from '@angular/core/testing/src/testing_internal';
|
||||
import {EventManager} from '@angular/platform-browser';
|
||||
import {HammerGestureConfig, HammerGesturesPlugin,} from '@angular/platform-browser/src/dom/events/hammer_gestures';
|
||||
|
||||
{
|
||||
describe('HammerGesturesPlugin', () => {
|
||||
let plugin: HammerGesturesPlugin;
|
||||
let mockConsole: any;
|
||||
let fakeConsole: any;
|
||||
if (isNode) return;
|
||||
|
||||
beforeEach(() => {
|
||||
mockConsole = {warn: () => {}};
|
||||
plugin = new HammerGesturesPlugin(document, new HammerGestureConfig(), mockConsole);
|
||||
beforeEach(() => { fakeConsole = {warn: jasmine.createSpy('console.warn')}; });
|
||||
|
||||
describe('with no custom loader', () => {
|
||||
beforeEach(() => {
|
||||
plugin = new HammerGesturesPlugin(document, new HammerGestureConfig(), fakeConsole);
|
||||
});
|
||||
|
||||
it('should implement addGlobalEventListener', () => {
|
||||
spyOn(plugin, 'addEventListener').and.callFake(() => {});
|
||||
|
||||
expect(() => {
|
||||
plugin.addGlobalEventListener('document', 'swipe', () => {});
|
||||
}).not.toThrowError();
|
||||
});
|
||||
|
||||
it('should warn user and do nothing when Hammer.js not loaded', () => {
|
||||
expect(plugin.supports('swipe')).toBe(false);
|
||||
expect(fakeConsole.warn)
|
||||
.toHaveBeenCalledWith(
|
||||
`The "swipe" event cannot be bound because Hammer.JS is not ` +
|
||||
`loaded and no custom loader has been specified.`);
|
||||
});
|
||||
});
|
||||
|
||||
it('should implement addGlobalEventListener', () => {
|
||||
spyOn(plugin, 'addEventListener').and.callFake(() => {});
|
||||
describe('with a custom loader', () => {
|
||||
// Use a fake custom loader for tests, with helper functions to resolve or reject.
|
||||
let loader: () => Promise<void>;
|
||||
let resolveLoader: () => void;
|
||||
let failLoader: () => void;
|
||||
|
||||
expect(() => plugin.addGlobalEventListener('document', 'swipe', () => {})).not.toThrowError();
|
||||
});
|
||||
// Arbitrary element and listener for testing.
|
||||
let someElement: HTMLDivElement;
|
||||
let someListener: () => void;
|
||||
|
||||
it('should warn user and do nothing when Hammer.js not loaeded', () => {
|
||||
spyOn(mockConsole, 'warn');
|
||||
// Keep track of whatever value is in `window.Hammer` before the test so it can be
|
||||
// restored afterwards so that this test doesn't care whether Hammer is actually loaded.
|
||||
let originalHammerGlobal: any;
|
||||
|
||||
expect(plugin.supports('swipe')).toBe(false);
|
||||
expect(mockConsole.warn)
|
||||
.toHaveBeenCalledWith(`Hammer.js is not loaded, can not bind 'swipe' event.`);
|
||||
// Fake Hammer instance ("mc") used to test the underlying event registration.
|
||||
let fakeHammerInstance: {on: () => void, off: () => void};
|
||||
|
||||
// Inject the NgZone so that we can make it available to the plugin through a fake
|
||||
// EventManager.
|
||||
let ngZone: NgZone;
|
||||
beforeEach(inject([NgZone], (z: NgZone) => { ngZone = z; }));
|
||||
|
||||
beforeEach(() => {
|
||||
originalHammerGlobal = (window as any).Hammer;
|
||||
(window as any).Hammer = undefined;
|
||||
|
||||
fakeHammerInstance = {
|
||||
on: jasmine.createSpy('mc.on'),
|
||||
off: jasmine.createSpy('mc.off'),
|
||||
};
|
||||
|
||||
loader = () => new Promise((resolve, reject) => {
|
||||
resolveLoader = resolve;
|
||||
failLoader = reject;
|
||||
});
|
||||
|
||||
// Make the hammer config return a fake hammer instance
|
||||
const hammerConfig = new HammerGestureConfig();
|
||||
spyOn(hammerConfig, 'buildHammer').and.returnValue(fakeHammerInstance);
|
||||
|
||||
plugin = new HammerGesturesPlugin(document, hammerConfig, fakeConsole, loader);
|
||||
|
||||
// Use a fake EventManager that has access to the NgZone.
|
||||
plugin.manager = { getZone: () => ngZone } as EventManager;
|
||||
|
||||
someElement = document.createElement('div');
|
||||
someListener = () => {};
|
||||
});
|
||||
|
||||
afterEach(() => { (window as any).Hammer = originalHammerGlobal; });
|
||||
|
||||
it('should not log a warning when HammerJS is not loaded', () => {
|
||||
plugin.addEventListener(someElement, 'swipe', () => {});
|
||||
expect(fakeConsole.warn).not.toHaveBeenCalled();
|
||||
});
|
||||
|
||||
it('should defer registering an event until Hammer is loaded', fakeAsync(() => {
|
||||
plugin.addEventListener(someElement, 'swipe', someListener);
|
||||
expect(fakeHammerInstance.on).not.toHaveBeenCalled();
|
||||
|
||||
(window as any).Hammer = {};
|
||||
resolveLoader();
|
||||
tick();
|
||||
|
||||
expect(fakeHammerInstance.on).toHaveBeenCalledWith('swipe', jasmine.any(Function));
|
||||
}));
|
||||
|
||||
it('should cancel registration if an event is removed before being added', fakeAsync(() => {
|
||||
const deregister = plugin.addEventListener(someElement, 'swipe', someListener);
|
||||
deregister();
|
||||
|
||||
(window as any).Hammer = {};
|
||||
resolveLoader();
|
||||
tick();
|
||||
|
||||
expect(fakeHammerInstance.on).not.toHaveBeenCalled();
|
||||
}));
|
||||
|
||||
it('should remove a listener after Hammer is loaded', fakeAsync(() => {
|
||||
const removeListener = plugin.addEventListener(someElement, 'swipe', someListener);
|
||||
|
||||
(window as any).Hammer = {};
|
||||
resolveLoader();
|
||||
tick();
|
||||
|
||||
removeListener();
|
||||
expect(fakeHammerInstance.off).toHaveBeenCalledWith('swipe', jasmine.any(Function));
|
||||
}));
|
||||
|
||||
it('should log a warning when the loader fails', fakeAsync(() => {
|
||||
plugin.addEventListener(someElement, 'swipe', () => {});
|
||||
failLoader();
|
||||
tick();
|
||||
|
||||
expect(fakeConsole.warn)
|
||||
.toHaveBeenCalledWith(
|
||||
`The "swipe" event cannot be bound because the custom Hammer.JS loader failed.`);
|
||||
}));
|
||||
|
||||
it('should load a warning if the loader resolves and Hammer is not present', fakeAsync(() => {
|
||||
plugin.addEventListener(someElement, 'swipe', () => {});
|
||||
resolveLoader();
|
||||
tick();
|
||||
|
||||
expect(fakeConsole.warn)
|
||||
.toHaveBeenCalledWith(
|
||||
`The custom HAMMER_LOADER completed, but Hammer.JS is not present.`);
|
||||
}));
|
||||
});
|
||||
});
|
||||
}
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user