angular-docs-cn/modules/@angular/platform-browser/testing/dom_test_component_renderer.ts

import {Inject, Injectable} from '@angular/core';
import {DOCUMENT} from '../src/dom/dom_tokens';
import {getDOM} from '../src/dom/dom_adapter';
import {TestComponentRenderer} from '@angular/compiler/testing';
import {el} from './browser_util';

/**
 * A DOM based implementation of the TestComponentRenderer.
 */
@Injectable()
export class DOMTestComponentRenderer extends TestComponentRenderer {
  constructor(@Inject(DOCUMENT) private _doc: any /** TODO #9100 */) { super(); }

  insertRootElement(rootElId: string) {
    let rootEl = el(`<div id="${rootElId}"></div>`);

    // TODO(juliemr): can/should this be optional?
    let oldRoots = getDOM().querySelectorAll(this._doc, '[id^=root]');
    for (let i = 0; i < oldRoots.length; i++) {
      getDOM().remove(oldRoots[i]);
    }
    getDOM().appendChild(this._doc.body, rootEl);
  }
}