Questions tagged [rxjs-observables]
759 questions
3
votes
1 answer
RxJS - Using pairwise to confirm and revert input field
So I'm a little new to observables, I'm struggling with a scenario, and I thought it might be a good candidate for an SO question. Here we go...
The scenario is this: I have a drop-down field; when it is changed, I want to
check a condition based…
Ross Brasseaux
- 3,879
- 1
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3
votes
1 answer
Template binding with function return Observable and async pipe
Note this is simplified question of Angular template binding with Observable async pipe issue
template:
{{foo()$ | async}}
source code:
import { Component } from "@angular/core";
import { BehaviorSubject, of, Observable } from…
Gelin Luo
- 14,035
- 27
- 86
- 139
3
votes
1 answer
How cancel angular http request made in RXJS Effects
I want to cancel the http request made in RXJS effects in angular 8.
@Effect() getReport$ = this.action$.pipe(
ofType(ActionTypes.GET_WIDGET),
map(toPayload),
mergeMap(payload => {
return this.dashboardService.getReport(payload).pipe(
…
Rahul Tokase
- 1,048
- 9
- 25
3
votes
0 answers
How and when does a Subscription on an Observable get automatically unsubscribed?
I want to know, when to unsubscribe on a Observable Subscription.
And when there is no need to unsubscribe.
It is kind of hard to understand the concept of the subscriptions.
I give you an example:
this.http
.get(
environment.baseUrl +…
Luxusproblem
- 1,913
- 11
- 23
3
votes
3 answers
rxjs: Combine result of observables while already displaying the first with async pipe
What is the best way in angular with rxjs to already display the result of a first observable, and combining the data when other observables are finished?
Example:
@Component({
selector: 'app-component',
template: `
devqon
- 13,818
- 2
- 30
- 45
2
votes
2 answers
How to re-render a component when data changes Angular js
I have three components: userlist page, userdetails page, and inside userdetails there is a subcomponent (Child) that displays a list of users like (Related),
when I enter user1 I see his name and email and on the other side there is a that will…
Rakh
- 33
- 3
2
votes
2 answers
RxJS: Ensure Optional Object Property is Defined
I need a RxJS operator that can check that if a property on an object exists, and then change the type to correctly reflect this.
I already have an operator that will do this for an emitted value:
const notUndefined = () =>
filter
Mikkel R. Lund
- 2,336
- 1
- 31
- 44
2
votes
1 answer
RxJS call function 1 second after subsccribe to an observable
Lets say I have an angular http Observable.
I'm not sure is it going to resolve after 100ms or 5 seconds and I would like to trigger a loading spinner if the delay is more than a second.
Is someone know an elegant way to do that?
I was thinking that…
Kaloyan Stamatov
- 3,894
- 1
- 20
- 30
2
votes
1 answer
RXJS SwitchMap not working properly with Resolver after Angular Upgrade
I have a component where a user chooses a report type to generate.
The component.ts function is like so:
generateReport(reportType, projectReport) {
this.showSpinner = true;
if(reportType === 'project-weekly-report')
…
Tom O'Brien
- 1,741
- 9
- 45
- 73
2
votes
1 answer
How to replicate a promise chain in Angular using Observable?
I'm new to angular and migrating a project from angularJS to angular. I'm having below issue with the existing flow.
1.authcomponent:
function FuncBasedOnLogin()
{ authServices.hasLoggedIn(dataService.dataModel.tenant).then(function (isLoggedIn)
…
dhanush shetty
- 33
- 4
2
votes
1 answer
forkJoin on NestJS not working after migration to newer version
I'm running nestjs application and have a peace of code that using forkJoin
const results: string[] = [];
const args = ['arg1', 'arg2', 'arg3', 'arg4', 'arg5', 'arg6'];
....
switchMap(() => {
const setToHandle = [];
args.forEach(arg =>…
Vegas Rico
- 73
- 9
2
votes
1 answer
How to simplify nested HTTP calls that use mergeMap
I need to sequentially call multiple HTTP requests. Currently I have this huge epic where I pass all API requests and then try to fire them one by one using mergeMaps. It works, but I believe there must be some easier or cleaner way but. All I found…
bdobry
- 190
- 1
- 8
2
votes
2 answers
Ordering RXJS streams by data property
I have an issue where I'm attempting to order multiple distinct streams from a time series database. Assuming that all the data in each stream is sorted by timestamp, given the following code how would I modify streams dataA$ and dataB$ such that…
Josh C.
- 370
- 2
- 8
2
votes
1 answer
Best practices for avoiding memory leaks in angular
I'm trying detect and fix potential memory leaks in my angular/spartacus application.
So basically I'm looking for any "subscribe(..." calls in my code base and evaluate what I can do.
I know that simplest form is simply to use observables directly…
Sergej Bjakow
- 21
- 1
2
votes
1 answer
how to pass data between concatmap in RXJS Angular
I have a pipe on a observable, the code is like below:
.pipe(
concatMap(() => this.security.getUser()),
tap((partyId) => {
if (!partyId) {
window.location.assign(`${environment.redirectURL1}/dashboard/login`);
…
Fazla Elahi Md Jubayer
- 177
- 2
- 12