试图让 Angular 2 在渲染之前等待数据加载

Question

我有多个 XML 文件需要在初始渲染之前加载。我有的是 app.module.ts

import { DataProvider } from './xml-provider'

export function dataProviderFactory(provider: DataProvider) {
  return () => provider.load();
}

providers: [
    DataProvider,
    { provide: APP_INITIALIZER, useFactory: dataProviderFactory, deps: [DataProvider], multi: true }
  ],

然后在xml-provider.ts

load(){
  let promises:Promise<any>[] = [];
  promises.push(this.loader1());
  promises.push(this.loader2());

  Promise.all(promises).then(
    (values) => { 
      console.log("Promise all finished: " + values);
      return true; 
    }
  );
}



  private loader1():Promise<any> {
    return new Promise((resolve, reject) => {
      this.http.get('assets/data.xml')
        .map(res => {
          let data;
          parseString(res.text(), { trim: true } ,function (err, result) {
            data = result.xml;
          });
          this.xmldata = data;
        })
        .subscribe(data => { resolve(true); })
    })    
  }

当我将 loader1 作为加载函数时，Angular 会一直等到文件加载完毕，一切正常。现在我已经添加了更多文件，它不会等待加载到 return。我错过了什么让 app.module.ts 等待所有文件加载完毕？

Answer 1

Promise.all前面少了一个return。我希望它能解决问题。

load(){
  let promises:Promise<any>[] = [];
  promises.push(this.loader1());
  promises.push(this.loader2());

  //// Missing return was here
  return Promise.all(promises).then(
    (values) => { 
      console.log("Promise all finished: " + values);
      return true; 
    }
  );
}

试图让 Angular 2 在渲染之前等待数据加载

trying to get Angular 2 to wait for data(s) to load before rendering

angular-promise

angular