Angular 2 templates use a special Async pipe to be able to render out Observables. This lesson covers the syntax used to create an Observable in Angular 2 and then to render it out in the template.
import {Component} from ‘angular2/core‘;
import {bootstrap} from ‘angular2/platform/browser‘;
import {Observable} from ‘rxjs/Observable‘;
import ‘rxjs/add/observable/interval‘
@Component({
selector: ‘app‘,
template: `<h1>{{clock | async}}</h1>`
})
class App {
clock = Observable.interval(1000);
}
bootstrap(App);
[Angular 2] Rendering an Observable with the Async Pipe
原文：http://www.cnblogs.com/Answer1215/p/5433549.html