I'm trying to use forkJoin
on two Observables. One of them starts as a stream... If I subscribe to them directly I get a response, forkJoin
isn't firing though. Any ideas?
private data$: Observable<any[]>;
private statuses$: Observable<any[]>;
private queryStream = new Subject<string>();
....
this.data$ = this.queryStream
.startWith('')
.flatMap(queryInput => {
this.query = queryInput
return this._companyService.getCompanies(this.queryRequired + ' ' + this.query, this.page, this.sort);
})
.share();
...
Observable.forkJoin(this.statuses$, this.companies$)
.subscribe(res => {
console.log('forkjoin');
this._countStatus(res[0], res[1]);
});
// This shows arrays in the console...
this.statuses$.subscribe(res => console.log(res));
this.companies$.subscribe(res => console.log(res));
// In the console
Array[9]
Array[6]
A very common problem with forkJoin
is that it requires all source Observables to emit at least one item and all of them have to complete.
In other words if this.statuses$
or this.companies$
doesn't emit any item and until they both complete the forkJoin
won't emit anything.
this.statuses$.subscribe(
res => console.log(res),
undefined,
() => console.log('completed'),
);