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().
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) => { //... }) 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>) => { //... }) 
combineLatest will emit each time any of the inner observables emits. The OP wants this to only happen whne all inner observables are complete.
combineLatest will only fire after every inner observable fires at least once as well as forkJoin. The only difference between two of them is that the forkJoin performs parallel execution and finishes (completes) while combineLatest performs serial execution (using concat inside) and does not finish (complete). So, combineLatest should work well for OP as well. And also see: stackoverflow.com/a/41797505/1331040
.toPromise()and then you know how to deal with itcomplete()method of the observer. For example, HTTP requests returns observable and the observable is finished once its subscription is fired.