subscribe isn’t deprecated, only the variant you’re using is deprecated. In the future, subscribe will only take one argument: either the next handler (a function) or an observer object. So in your case you should use: .subscribe({ next: this.handleUpdateResponse.bind(this), error: this.handleError.bind(this) }); See these GitHub issues: https://github.com/ReactiveX/rxjs/pull/4202 https://github.com/ReactiveX/rxjs/issues/4159
A Subject or Observable doesn’t have a current value. When a value is emitted, it is passed to subscribers and the Observable is done with it. If you want to have a current value, use BehaviorSubject which is designed for exactly that purpose. BehaviorSubject keeps the last emitted value and emits it immediately to new … Read more
So the answer is no, you don’t. Ng2 will clean it up itself. The Http service source, from Angular’s Http XHR backend source: Notice how it runs the complete() after getting the result. This means it actually unsubscribes on completion. So you don’t need to do it yourself. Here is a test to validate: fetchFilms() … Read more
EDIT: as of 2021, the proper way is to use the shareReplay operator natively proposed by RxJs. See more details in below answers. Cache the data and if available cached, return this otherwise make the HTTP request. import {Injectable} from ‘@angular/core’; import {Http, Headers} from ‘@angular/http’; import {Observable} from ‘rxjs/Observable’; import ‘rxjs/add/observable/of’; //proper way to … Read more
I think that you need to import this: import ‘rxjs/add/operator/map’ Or more generally this if you want to have more methods for observables. WARNING: This will import all 50+ operators and add them to your application, thus affecting your bundle size and load times. import ‘rxjs/Rx’; See this issue for more details.
A BehaviorSubject holds one value. When it is subscribed it emits the value immediately. A Subject doesn’t hold a value. Subject example (with RxJS 5 API): const subject = new Rx.Subject(); subject.next(1); subject.subscribe(x => console.log(x)); Console output will be empty BehaviorSubject example: const subject = new Rx.BehaviorSubject(0); subject.next(1); subject.subscribe(x => console.log(x)); Console output: 1 In … Read more
TL;DR For this question there are two kinds of Observables – finite value and infinite value. http Observables produce finite (1) values and something like a DOM event listener Observable produces infinite values. If you manually call subscribe (not using async pipe), then unsubscribe from infinite Observables. Don’t worry about finite ones, RxJs will take … Read more
BehaviorSubject is a type of subject, a subject is a special type of observable so you can subscribe to messages like any other observable. The unique features of BehaviorSubject are: It needs an initial value as it must always return a value on subscription even if it hasn’t received a next() Upon subscription, it returns … Read more
Promise A Promise handles a single event when an async operation completes or fails. Note: There are Promise libraries out there that support cancellation, but ES6 Promise doesn’t so far. Observable An Observable is like a Stream (in many languages) and allows to pass zero or more events where the callback is called for each … Read more