服务事件不会正确影响模板 [英] Service events do not affect template correctly

问题描述

在 google 中验证，使用 Angular2.

Auth in google, use Angular2.

首先，在 HTML 中，我加载 google api 库:

First, in HTML, I load google api library:

//index.html
//...
<script> 
       var googleApiClientReady = function() {
          ng2Gauth.googleApiClientReady(gapi);
      }
    </script>    
    <script src="https://apis.google.com/js/client.js?onload=googleApiClientReady"></script>
//...

在 Angular2 服务之后，我处理 google auth 数据并发出事件以通知组件 google api 是否准备就绪:

After in Angular2 service I handle google auth data and emit event to inform component if google api is ready:

//google auth service .ts
import {Injectable, EventEmitter} from 'angular2/core';

@Injectable()
export class GoogleAuthService {

    isGoogleApiReady: EventEmitter<boolean>;

    constructor() {
        window['ng2Gauth'] = this; //is it correct way?
        this.isGoogleApiReady = new EventEmitter;       
    }
    //it fires from outside of Angular scope
    public googleApiClientReady(gapi){
        this.gapi.auth.init( () => { 
            this.isGapiReady.emit(true);
        })
    };
//...

在这里，在组件中，我选中复选框，或禁用按钮，并执行其他模板操作.

Here, in the component, I check checkbox, or make buttons disabled, and do other template stuff.

//gauth component
import {Component} from 'angular2/core';
import {GauthService} from './gauth.service';

@Component({
    selector: 'gauth',
    template: `<input type="checkbox" [(ngModel)]="isReady"> Api ready

export class GauthComponent {
    constructor (private _gauthService:GauthService) {
        _gauthService.isGoogleApiReady.subscribe( (flag) =>   this.gapiOnReady(flag) )

  public isReady = false
  gapiOnReady(flag: boolean) { //it fires, 
    this.isReady = true;       //but not affect on template correctly
    console.log('gapi loaded') 
    this._gauthService.checkAuth();     
  }
}

看起来一切正常，但浏览器(Chrome，FF)中存在奇怪的错误 - 如果页面在活动浏览器的选项卡上加载 - 看起来没有任何反应 - 复选框没有检查，如果我在浏览器加载时及时打开其他选项卡页面，一切正常.

It looks like all should work but there is weird bug in browsers (Chrome, FF) - if page loads on active browser's tab - it looks like nothing happens - checkbox no checks, if I open other tabs in time when browser load page, all is ok.

如何解决?是 Angular 错误还是我做错了?

How to fix it? Is it Angular bug or I do it wrong way?

推荐答案

将 NgZone 注入到组件中，并用 zone.run() 初始化库代码，这样库代码使用区域补丁异步 API，Angular 知道何时需要运行变更检测

Inject NgZone into a component and initialize the library code with zone.run(), this way the library code uses zones patched async API and Angular knows when change detection runs are necessary

var googleApiClientReady;
constructor(private zone: NgZone) {
} 

public googleApiClientReady(gapi){          
  zone.run(function () { 
    this.gapi.auth.init( () => { 
        this.isGapiReady.emit(true);
    })
  });
}  

和

gapiOnReady(flag: boolean) {
  zone.run(function() {
    this.isReady = true;       //but not affect on template correctly
    console.log('gapi loaded') 
    this._gauthService.checkAuth();   
  });
}

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