delay() is used to introduce a delay between events emitted by the observable. But the observable never emits any event. It just errors immediately. What you’re looking for is retryWhen(), which allows deciding after how long to retry: RxJS 5: .retryWhen(errors => errors.delay(1000).take(10)) RxJS 6: import { retryWhen, delay, take } from ‘rxjs/operators’ someFunction().pipe( // … Read more
To get data from an observable, you need to subscribe: this.singleEvents$.subscribe(event => this.event = event); In the template you can directly bind to observables using the async pipe: {{singleEvents$ | async}}
I encountered a similar problem and solved it using Aran’s suggestion to reference Cory Rylan’s Angular 2 Observable Data Services blog post. The key for me was using BehaviorSubject. Here’s the snippets of the code that ultimately worked for me. Data Service: The data service creates an internal BehaviorSubject to cache the data once when … Read more
As per this you need update typescript 2.3.4 or rxjs 6 alpha go the your package.json file in your project update typescript or rxjs version. Example “typescript”: “2.3.4” do npm install update(06/29/2017):- As per the comments typescript “2.4.0” working.
When you use a dependency that is packaged with CommonJS, it can result in larger slower applications Starting with version 10, Angular now warns you when your build pulls in one of these bundles. If you’ve started seeing these warnings for your dependencies, let your dependency know that you’d prefer an ECMAScript module (ESM) bundle. … Read more
The current “pipable” variant of this operator is called finalize() (since RxJS 6). The older and now deprecated “patch” operator was called finally() (until RxJS 5.5). I think finalize() operator is actually correct. You say: do that logic only when I subscribe, and after the stream has ended which is not a problem I think. … Read more
Actually I have imports messed up. In latest version of RxJS we can import it like that: import ‘rxjs/add/observable/of’;
For calls that depend on previous result you should use concatMap firstPOSTCallToAPI(‘url’, data).pipe( concatMap(result1 => secondPOSTCallToAPI(‘url’, result1)) concatMap( result2 => thirdPOSTCallToAPI(‘url’, result2)) concatMap(result3 => fourthPOSTCallToAPI(‘url’, result3)) …. ).subscribe( success => { /* display success msg */ }, errorData => { /* display error msg */ } ); if your async method does not depend on … Read more
Since you are already using Observables, simply make full use of it 🙂 Obersvable.interval() is your good friend here: In your component, do this: Observable .interval(2*60*1000) .timeInterval() .mergeMap(() => this.notificationService.getNotifications(this.token)) .subscribe(data => { console.log(data); }); Explanation: .interval() creates an observable that emits an event every 2 minutes. .timeInterval() convert an Observable that emits items into … Read more
tl;dr; mergeMap is way more powerful than map. Understanding mergeMap is the necessary condition to access full power of Rx. similarities both mergeMap and map acts on a single stream (vs. zip, combineLatest) both mergeMap and map can transform elements of a stream (vs. filter, delay) differences map cannot change size of the source stream … Read more