rxjs

I am a newbie to RxJs and I have an API that I am using for geocoding that provides a function like the following: simpleGeocode(options) * where options = { address: {addr: ... }, success: Function, failure: Function}. The success function returns the geocoded LatLon object. I am using this in Angular app with NGRX Effects and so I would like it to have it as an Observable so I can use the standard Effect setup like: @Effect() public calculateLocation: Observable<void> = this.actions .ofType(actions.CALCULATE_LOCATION) .switchMap((action) => { let location = action.payload; let options = {

I want to poll an endpoint no faster than once a second, and no slower than the time it takes to poll the endpoint. There should never be more than one request outstanding. I want a reactive programming way to poll an endpoint at least once a second, but if the endpoint takes longer than 1 second, the next request fires immediately. In the marble diagram below, the 2nd and 3rd requests take longer than 1 second, but the 4th and 5th requests finish quicker. The next request fires either on the 1 second boundary, or immediately upon obtaining the data from the last outstanding request. s---s---s

I'm trying to write a test for an angular service which has a Subject property and a method to call .next() on that subject. The service is the following: @Injectable() export class SubjectService { serviceSubjectProperty$: Subject<any> = new Subject(); callNextOnSubject(data: any) { this.serviceSubjectProperty$.next(data); } } And the test file for that service: import { TestBed, inject } from '@angular/core/testing'; import { SubjectService } from './subject.service'; describe('SubjectService', () => { beforeEach(() => { TestBed.configureTestingModule({ providers: [ SubjectService ] }); });

I have seen a tutorial on rxjs as like this. My question is: 1) What is the usage of take(1) here? I see a lot of explanation online but i don't really get it. Also, i don't see any benefit of using take(1) in this code. And the author do use take(1) on every return function in REST api related service. 2) The author did not unsubscribe after subscribe. Is it because the author use take(1) therefore manual unsubscribe is not needed? 3) What if i want to implement catch function. Should i implement it before take or after take. getProfile() { // this is a call to REST API return this.service

Is there an operator in RxJS that debounces without delaying the "first event in a burst", but delaying (and always emitting) the "last event in a burst"? Something like this: ---a----b-c-d-----e-f--- after awesome-debounce(2 dashes) becomes: ---a----b------d--e----f while a normal debounce would be: -----a---------d-------f It's kind of a mix between throttle and debounce... martin Hmmm, this is the easiest solution I can think of. The interesting part for you is the awesomeDebounce() function that creates the sub-chain. It basically just combines throttle() and debounceTime() operators:

I am implementing caching HTTP results in Angular application. From what I know both of the following code works, but I need to know if they are doing exactly the same thing, or I am missing something important? publishLast getPosts() { if( !this.posts$ ) { this.posts$ = this.http.get('api').publishLast().refCount(); return this.posts$; } return this.posts$; } publishReplay getPosts() { if( !this.posts$ ) { this.posts$ = this.http.get('api').publishReplay(1).refCount(); return this.posts$; } return this.posts$; } publishLast shares (as the name suggests) the last emitted value - which can only

I have an angular2 app I want to test with protractor. In this app I have a page with a graph that is being updated in regular intervals with autogenerated data. Apparently one feature of protractor is waiting for scripts and http calls to finish before executing test code. However, if there is a constantly polling script that never finishes, protractor will wait forever and time out after a certain time. In angular1 this could be solved by implementing the polling with $interval , which protractor does not wait for. Unfortunately in angular2 there is no $interval and the correct way to