observable Questions

2

Solved

I would like to observe whenever a property of a third party object is changed. I'm taking the approach of assigning a custom setter but my console.log below is never invoked. Why is that? Is there...
Furious asked 29/11, 2021 at 10:6

3

Solved

For rxjs, can I provide an initial value when using distinctUntilChanged? It seems that the equals check is skipped entirely when no previous value was received. I'd like to not emit anything when ...
Pertinacious asked 16/8, 2018 at 12:17

3

Solved

I have two components. Child component has an event (EventEmitter). Parent component has handler with long time method. I need to wait for finishing of executing of my method (longTimeMethod) befo...
N asked 8/11, 2017 at 7:0

5

I am trying to access the localStorage using Angular 4 and look for changes in the localStorage values using the Observables: Here's the code I have been working on: userNameObservable: Observabl...
Submerged asked 9/8, 2017 at 11:21

3

Solved

I'm trying to understand throttleTime vs debounceTime and which one is to be used when? I have an upvote button that makes an API request to the backend (which counts the votes). User can submit bu...
Hawser asked 5/6, 2019 at 12:23

4

I am trying to create an ObservableTimer that ticks up to a certain number. I already have logic to do that, but when I try to unsubscribe from it I get a "Cannot read property 'unsubscribe' of und...
Truancy asked 27/1, 2017 at 20:31

2

I'm struggling to get a unit test around an Observable to behave the way I expect. I'm using an Observable essentially just to notify that a process has completed. There's no async code in the logg...
Carola asked 26/4, 2020 at 18:32

4

What is the best strategy to unsubscribe multiple observable in angular? Just to be clear I use this approach when the application is not big and do not need solutions such as ngrx that in this cas...
Bairn asked 29/3, 2019 at 12:42

7

Solved

I'm using Android MVVM architecture with LiveData. I have an object like this public class User { private String firstName; private String lastName; public String getFirstName() { return first...
Roughish asked 29/12, 2017 at 9:34

8

Solved

In my Angular 2 component I have an Observable array list$: Observable<any[]>; In my Template I have <div *ngIf="list$.length==0">No records found.</div> <div *ngIf="list$...
Intrauterine asked 27/6, 2016 at 15:13

8

Solved

I’m currently evaluating the pros ‘n’ cons of replacing Angular’s resp. RxJS’ Observable with plain Promise so that I can use async and await and get a more intuitive code style. One of our typica...
Accrescent asked 11/5, 2019 at 16:10

3

Solved

I've built a basic counter React app with a simple MobX store. I was able to create an observable MobX status using makeObservable but for some reason when I try to use makeAutoObservable I get the...
Lunt asked 12/7, 2021 at 18:56

3

Solved

I've been hung up about this topic lately. It seems AsyncIterables and Observables both have stream-like qualities, though they are consumed a bit differently. You could consume an async iterable ...
Clements asked 10/6, 2020 at 19:51

3

Solved

I have that code method(): Observable<boolean> { return this._http.get('sessionId=' + sessionId).map(res=> { if (res.status === "success") { return true; } return false; }); } But...
Torpedoman asked 11/2, 2017 at 16:37

2

I am using NgRx in my Angular project. I want to access the products that are stored in my store from my ProductsComponent. ProductsComponent.ts ... import { select, Store } from '@ngrx/store'; ......
Thurmanthurmann asked 25/8, 2021 at 8:54

2

Solved

I'm currently trying to teach myself Angular2 and TypeScript after happily working with AngularJS 1.* for the last 4 years! I have to admit I am hating it but I am sure my eureka moment is just aro...
Ehtelehud asked 8/2, 2016 at 11:24

10

Solved

I have service which returns an observable which does an http request to my server and gets the data. I want to use this data but I always end up getting undefined. What's the problem? Service: @...
Darg asked 27/3, 2017 at 20:17

3

How can I set a delay in retryWhen? import 'rxjs/add/operator/retry'; import 'rxjs/add/operator/retrywhen'; ... constructor(http: Http) { var headers = new Headers(); headers.append('Content...
Nonrecognition asked 25/8, 2016 at 13:40

2

Solved

In the Observables forkJoin documentation, it says that args can be an array but it doesn't list an example doing so: https://github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/operator...
Medius asked 27/2, 2016 at 22:50

2

Solved

Angular 7 docs provide this example of practical usage of rxjs Observables in implementing an exponential backoff for an AJAX request: import { pipe, range, timer, zip } from 'rxjs'; import { ajax...
Reduction asked 26/10, 2018 at 19:26

4

Solved

I use the following code for timer: export class TimerService { private ticks: number = 0; private seconds: number = 0; private timer; constructor(seconds: number) { this.seconds = seconds; ...
Inexplicable asked 21/7, 2017 at 9:4

2

Solved

I'm looking for an RxJS operator (or a combination of operators) which will allow me to achieve this: Every event fired by the observable should be handled by the order it was triggered (no skippi...
Guria asked 16/7, 2021 at 19:50

4

Solved

I'm making a drag and drop application and I have created an observable to the mouse position, that repositions my drag-object. mouseMove$: any; constructor(){ this.mouseMove$ = Observable.fromE...
Holophrastic asked 16/12, 2016 at 19:17

4

Solved

// ticker$ will update every 3s // showHand$ will only triger after user click button // I would like to take last ticker price as user order price when user click button let lastPrice: number; t...
Inflation asked 25/9, 2017 at 4:57

0

Sometimes I'd like to use the RxJS operators to manipulate an endless asynchronous iterable without buffering the values. It is easy to turn an iterable into an Observable. Are there downsides in t...
Pascale asked 5/7, 2021 at 10:48

© 2022 - 2024 — McMap. All rights reserved.