2018-03-19 21:51:51 -07:00

49 lines
1.2 KiB
TypeScript

// #docregion
import { Component, OnInit } from '@angular/core';
import { Observable, of } from 'rxjs';
import { catchError, startWith } from 'rxjs/operators';
import { TwainService } from './twain.service';
// #docregion component
@Component({
selector: 'twain-quote',
// #docregion template
template: `
<p class="twain"><i>{{quote | async}}</i></p>
<button (click)="getQuote()">Next quote</button>
<p class="error" *ngIf="errorMessage">{{ errorMessage }}</p>`,
// #enddocregion template
styles: [
`.twain { font-style: italic; } .error { color: red; }`
]
})
export class TwainComponent implements OnInit {
errorMessage: string;
quote: Observable<string>;
constructor(private twainService: TwainService) {}
ngOnInit(): void {
this.getQuote();
}
// #docregion get-quote
getQuote() {
this.errorMessage = '';
this.quote = this.twainService.getQuote().pipe(
startWith('...'),
catchError( (err: any) => {
// Wait a turn because errorMessage already set once this turn
setTimeout(() => this.errorMessage = err.message || err.toString());
return of('...'); // reset message to placeholder
})
);
// #enddocregion get-quote
}
}
// #enddocregion component