angular-docs-cn/aio/content/examples/pipes/src/app/hero-async-message.component.ts
2018-03-19 21:51:51 -07:00

40 lines
883 B
TypeScript

// #docregion
import { Component } from '@angular/core';
import { Observable, interval } from 'rxjs';
import { map, take } from 'rxjs/operators';
@Component({
selector: 'app-hero-message',
template: `
<h2>Async Hero Message and AsyncPipe</h2>
<p>Message: {{ message$ | async }}</p>
<button (click)="resend()">Resend</button>`,
})
export class HeroAsyncMessageComponent {
message$: Observable<string>;
private messages = [
'You are my hero!',
'You are the best hero!',
'Will you be my hero?'
];
constructor() { this.resend(); }
resend() {
this.message$ = interval(500).pipe(
map(i => this.messages[i]),
take(this.messages.length)
);
}
}
// #enddocregion
// Alternative message$ formula:
// this.message$ = fromArray(this.messages).pipe(
// map(message => timer(500),
// map(() => message)),
// concatAll()
// );