CODEWITHSUNDEEP
angulartypescriptrxjsobservable
user5417542
user5417542

Reputation: 3386

Wait for last subscription to end

I have following setup:

    let result = service.getResults();

    result.data.forEach((row:any) => {
          this.myService
            .getObject(row.id)
            .subscribe((object:any) => {
              //...
            })
        );
      }

I want do do something, after all the subscriptions of getObject(row.id) have finished. I know there's the add() function but it will do this for every Subscription. Coming from Promises I would have stored every Promise and then in an array and just called Promise.all().

Upvotes: 0

Views: 3071

Answers (2)

Vadim
Vadim

Reputation: 3439

I want do do something, after all the subscriptions of getObject(row.id) have finished.

Better to use forkJoin for your example. From official docs:

forkJoin will wait for all passed Observables to complete and then it will emit an array with last values from corresponding Observables.

Try to do it in this way: 

import { forkJoin } from 'rxjs';

const rowObjects$ = result.data.map(rd => this.myService.getObject(rd.id));

forkJoin(rowObjects$)
  .subscribe((object:any) => {
    //...
  })

Upvotes: 4

Harun Yilmaz
Harun Yilmaz

Reputation: 8558

You can use combineLatest to combine all the observables and wait until every observable fires at least once. 

import {combineLatest} from 'rxjs';
...



let result = service.getResults();

const observablesToCombine = [];

result.data.forEach((row:any) => {
      observablesToCombine.push(this.myService.getObject(row.id));
})

combineLatest(observablesToCombine).subscribe((object: Array<any>) => {
     //...
})

Upvotes: -1

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