Which rxSwift operator to use in this scenario?

Question

Here is my scenario. I have one Subject that is being used together with another Subject in a combineLatest. So far so good. Now i push onCompleted on one of the Subjects but the CombineLatest is still working when the other subject pushes some event.

What i want is that as soon as either of the subjects has completed i want the combineLatest to stop working. Is CombineLatest the right Operator to use here ? Or is there any other operator available ?

Answer 1

You should use takeUntil operator:

let subject1 = PublishSubject<Void>()
let subject2 = PublishSubject<Void>()
let subjectWasCompleted = Observable<Void>
    .merge(
        subject1.ignoreElements().andThen(.just(())),
        subject2.ignoreElements().andThen(.just(()))
    )

Observable.combineLatest(subject1, subject2)
    .takeUntil(subjectWasCompleted)
    .subscribe()
    .disposed(by: disposeBag)