Flattening nested Observables

Question

I\'m a stuck in nested observable hell and could do with a hand.

I have the following block of code

return this.findUser(term).map( users => {
  r         


        

Answer 1

One solution would be to use forkJoin to join and then map the results of calls to getLastLogin to users:

// forkJoin will return Observable, so use switchMap.

return this.findUser(term).switchMap(users => Observable.forkJoin(

  // Map the array of users to the array of observables to be joined. Use
  // first to ensure the observables complete.

  users.map(user => this.getLastLogin(user.user_id).first()),

  // Use forkJoin's selector to add the last_login to each user and return
  // the users.

  (...logins) => {
    users.forEach((user, index) => { user.last_login = logins[index]; });
    return users;
  }
));