Angular 2 Async Pipe with Ngfor Observable

What is async pipe?

The async pipe subscribes to an Observable and returns the latest changed value. When a new value is changed, the async pipe marks the component to be checked for changes. When the component gets destroyed the async pipe unsubscribes automatically to avoid potential memory leaks.

How to use async pipe in Angular 2?

observable_expression | async

Example,

@Component({
  selector: 'async-observable-pipe',
  template: '<div><code>observable|async</code>: Time: {{ time | async }}</div>'
})

export class AsyncObservablePipeComponent {
  time = new Observable<string>((observer: Subscriber<string>) => {
    setInterval(() => observer.next(new Date().toString()), 1000);
  });
}

The async pipe with ngFor in Angular 2,

*ngFor="#obj of (myAsyncObject | async)?.prop1?.prop2"

Reference,

https://angular.io/docs/ts/latest/api/common/index/AsyncPipe-pipe.html

I hope you are enjoying with this post! Please share with you friends!! Thank you!!!

Pin it

Anil Singh is an author, tech blogger, and software programmer. Book writing, tech blogging is something do extra and Anil love doing it. For more detail, kindly refer to this link..

My Tech Blog - https://www.code-sample.com/
My Books - Book 1 and Book 2