Rxjava: Why doOnComplete / doOnSubscribe / subscribe not called?

[i-schuetz]

Why are doOnComplete, doOnSubscribe (and also doFinally) not called?

//    val obs = createObservable()
val obs = createCompletable()

@JvmStatic fun main(args: Array<String>) {

    obs.doOnSubscribe {
        println("on subscribe!")
    }

    obs.doOnComplete {
        println("complete!")
    }

    obs.doFinally{
        println("dofinally!")
    }

    obs.subscribe{
        println("subscribe")
    }
}

fun createCompletable(): Completable =
    Completable.create{ emitter ->
        println("calling oncomplete")
        emitter.onComplete()
    }

fun createObservable(): Observable<Void> =
    Observable.create<Void> { emitter ->
        println("calling oncomplete")
        emitter.onComplete()
    }

Also, the subscribe block is called only when using Completable, with Observable<Void> this is also not called, why?

It seems that I'm missing something basic but not being able to figure out exactly what it is.

I assume that the reason subscribe is not called when using the observable, is that this reacts only to onNext (?), but why isn't doOnComplete called either?

[akarnokd]

The methods on the base reactive types return a new instance which you have to subscribe to or continue chaining:

createCompletable()
.doOnSubscribe {
        println("on subscribe!")
}
.doOnComplete {
        println("complete!")
}
.doFinally {
        println("dofinally!")
}
.subscribe{
        println("success")
}

[i-schuetz]

Ah, my bad! I thought these could be attached anywhere and it would somehow just work. Thanks!