How to chain two Completable in RxJava2

Question

I have two Completable. I would like to do following scenario: If first Completable gets to onComplete , continue with second Completable. The final results would be onComplete of second Completable.

This is how I do it when I have Single getUserIdAlreadySavedInDevice() and Completable login():

@Override
public Completable loginUserThatIsAlreadySavedInDevice(String password) {
    return getUserIdAlreadySavedInDevice()
            .flatMapCompletable(s -> login(password, s))

}

Answer 1

You are looking for andThen operator.

Returns a Completable that first runs this Completable and then the other completable.

firstCompletable
    .andThen(secondCompletable)

In general, this operator is a "replacement" for a flatMap on Completable:

Completable       andThen(CompletableSource next)
<T> Maybe<T>      andThen(MaybeSource<T> next)
<T> Observable<T> andThen(ObservableSource<T> next)
<T> Flowable<T>   andThen(Publisher<T> next)
<T> Single<T>     andThen(SingleSource<T> next)