CODEWITHSUNDEEP
androidrx-javareactive-programmingrx-java2
Masquitos
Masquitos

Reputation: 536

RxJava2 merged Observable doesn't stop

Why merge operator doesn't stopped after obs2 onCompleted? I am looking at diagram from this book

"Reactive Programming on Android with RxJava"

enter image description here

From my point of view if any of merged Observables is onCompleted, then another Observable also terminates (completed).

But its not. why so?

Here is my code. Obs1 should terminate just after Obs2, but it is endless

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button button = findViewById(R.id.btn);

        Observable.merge(obs1, obs2)
                .subscribe(data -> Log.d(TAG, String.valueOf(data)));
    }

    Observable<String> obs1 = Observable.interval(1, TimeUnit.SECONDS)
            .map(data -> "obs1: " + data);

    Observable obs2 =
            Observable.just(1, 2, 3, 4, 5)
                    .delay(1, TimeUnit.SECONDS)
                    .filter(data -> data < 5)
                    .map(data -> "obs2: " + data)
                    .doOnComplete(() -> Log.d(TAG, "done"));

D/MainActivity: obs1: 0
                obs2: 1
                obs2: 2
                obs2: 3
D/MainActivity: obs2: 4
                done
D/MainActivity: obs1: 1
D/MainActivity: obs1: 2
D/MainActivity: obs1: 3
D/MainActivity: obs1: 4
D/MainActivity: obs1: 5
D/MainActivity: obs1: 6

Upvotes: 0

Views: 603

Answers (1)

gokhan
gokhan

Reputation: 667

It's normal behaviour because first observable still emitting items on every second. Merge operator's onComplete method does not trigger until observed items onComplete method called

Upvotes: 1

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