CODEWITHSUNDEEP
javarx-java
regmoraes
regmoraes

Reputation: 5499

Get the penultimate observable of a chained map() call in Rx Java

I have two observables:

  1. Observable<User> createUser(UserData userData)
  2. Observable<Void> loginUser(User user)

After the user creates a new account I wish to login with that new account. So I've done this:

createUser(userData).map(user -> loginUser(user));

But in that way, I get an Observable<Void> as return. What I want to do is to call createUser(userData).map(user -> loginUser(user)) and get an Observable<User> as return. Something like this:

@Override
public Observable<User> createUserAndLogin(){

    createUser(userData).map(user -> loginUser(user));

}

How could I do this?

Upvotes: 0

Views: 82

Answers (1)

Reut Sharabani
Reut Sharabani

Reputation: 31349

Why not use log-in as a side-effect with doOnNext?

createUser(userData).doOnNext(user -> loginUser(user));

If you want to make sure the log-in happened:

createUser(userData).flatMap(user -> {
    // attach a callback to the log-in and return
    // the user from the previous call
    return loginUser(user).map(dontCare -> user);
});

But I'm not sure how it's going to work if loginUser emits nothing, so perhaps forcibly concat the value you want to the empty loginUser observable:

 createUser(userData).flatMap(user -> {
    // attach a callback to the log-in and return
    // the user from the previous call
    return loginUser(user).concatWith(Observable.just(user));
});

Upvotes: 1

Related Questions