`@angular/platform-server` provides the foundation for rendering an Angular app on the server. In order to achieve that, it uses a server-side DOM implementation (currently [domino][1]). For rendering on the server to work as closely as possible to running the app on the browser, we need to make DOM globals (such as `Element`, `HTMLElement`, etc.), which are normally provided by the browser, available as globals on the server as well. Currently, `@angular/platform-server` achieves this by extending the `global` object with the DOM implementation provided by `domino`. This assignment happens in the [setDomTypes()][2] function, which is [called in a `PLATFORM_INITIALIZER`][3]. While this works in most cases, there are some scenarios where the DOM globals are needed sooner (i.e. before initializing the platform). See, for example, #24551 and #39950 for more details on such issues. This commit provides a way to solve this problem by exposing a side-effect-ful entry-point (`@angular/platform-server/init`), that shims the `global` object with DOM globals. People will be able to import this entry-point in their server-rendered apps before bootstrapping the app (for example, in their `main.server.ts` file). (See also [#39950 (comment)][4].) In a future update, the [`universal` schematics][5] will include such an import by default in newly generated projects. [1]: https://www.npmjs.com/package/domino [2]: https://github.com/angular/angular/blob/0fc8466f1be392917e0c/packages/platform-server/src/domino_adapter.ts#L17-L21 [3]: https://github.com/angular/angular/blob/0fc8466f1be392917e0c/packages/platform-server/src/server.ts#L33 [4]: https://github.com/angular/angular/issues/39950#issuecomment-747598403 [5]: https://github.com/angular/angular-cli/blob/cc51432661eb4ab4b6a3/packages/schematics/angular/universal PR Close #40559
		
			
				
	
	
		
			42 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			TypeScript
		
	
	
	
	
	
			
		
		
	
	
			42 lines
		
	
	
		
			1.2 KiB
		
	
	
	
		
			TypeScript
		
	
	
	
	
	
| /**
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|  * @license
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|  * Copyright Google LLC All Rights Reserved.
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|  *
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|  * Use of this source code is governed by an MIT-style license that can be
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|  * found in the LICENSE file at https://angular.io/license
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|  */
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| import {applyShims} from '../src/shims';
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| 
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| describe('applyShims()', () => {
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|   if (isBrowser) return;  // NODE only
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| 
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|   const domino = require('domino');
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|   const globalClone = {...global};
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| 
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|   afterEach(() => {
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|     // Un-patch `global`.
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|     const currentProps = Object.keys(global) as (keyof NodeJS.Global)[];
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|     for (const prop of currentProps) {
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|       if (globalClone.hasOwnProperty(prop)) {
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|         (global as any)[prop] = globalClone[prop];
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|       } else {
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|         delete (global as any)[prop];
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|       }
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|     }
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|   });
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| 
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|   it('should load `domino.impl` onto `global`', () => {
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|     expect(global).not.toEqual(jasmine.objectContaining(domino.impl));
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| 
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|     applyShims();
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|     expect(global).toEqual(jasmine.objectContaining(domino.impl));
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|   });
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| 
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|   it('should define `KeyboardEvent` on `global`', () => {
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|     expect((global as any).KeyboardEvent).not.toBe((domino.impl as any).Event);
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| 
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|     applyShims();
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|     expect((global as any).KeyboardEvent).toBe((domino.impl as any).Event);
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|   });
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| });
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