Rxjs do a job after multiple observables has completed-CodePudding

Let's say I have 3 observables job1(), job2(), and job3(). I would like to call the finalJob() after all these 3 jobs has completed as the finalJob() is dependent on all 3 jobs. From what I know, I can achieve this by using Observable.forkJoin() like below:

forkJoin([this.job1(), this.job2(), this.job3()])
.subscribe(([result1, result2, result3]) => {.
    this.job1Completed = true;
    this.job2Completed = true;
    this.job3Completed = true;
    this.finalJob();
});

But the thing is I would like to run these 3 jobs simultaneously, so that each of these jobs can set their own completion status right after it has completed it's job, rather than waiting for another 2 jobs to complete then set the completion status all together, like below:

this.job1().subscribe((result1) => this.jodb1Completed = true);
this.job2().subscribe((result2) => this.jodb2Completed = true);
this.job3().subscribe((result3) => this.jodb3Completed = true);

finalJob(); // this has no guarantee all 3 jobs has completed

With the implementation above, I will not be able to call the finalJob() after all 3 jobs has completed. Is there any way to emit an event to call the finalJob() once all jobs has done?

CodePudding user response：

You can use the rxjs tap operator

forkJoin([
  this.job1().pipe(tap((result1) => this.jodb1Completed = true)),
  this.job2().pipe(tap((result2) => this.jodb2Completed = true)),
  this.job3().pipe(tap((result3) => this.jodb3Completed = true)),
])
.subscribe(response => {
  finalJob();
  console.log('done', respone)
});

CodePudding user response：

With finalize, for example. Or tap, if you want things to happen on every emission (edit: and/or if you are interested in the emitted values), not on completion (and if that makes any difference).

const stream1$ = this.job1().pipe(
    finalize(() => this.jodb1Completed = true)
);

const stream2$ = this.job1().pipe(
    finalize(() => this.jodb2Completed = true)
);

forkJoin([stream1$, stream2$]).subscribe(this.finalJob);