Bloc: Question about run blocs in sequence

[daviidmorales]

I have an app with an AuthBloc(the only functionality of the Bloc is authenticate the user), but i need to run other bloc(a bloc which verify my app version) before that the AuthBloc run.

I'm starting to use bloc and i don't know how i can do it, i've considerate to use the other bloc before the AuthBloc but i need the AuthBloc globally and i don't know how run the blocs in sequence before of the MaterialApp.

Do you know or do you have any example that how i can do it?

Sorry for my english.

[felangel]

Hi @daviidmorales 👋
Thanks for opening an issue!

Regarding your question, why do you need a bloc to verify the app version? Can't you just have a service to do the verification? If so, then you can inject the service into your AuthBloc and call the verify function before authenticating the user.

Let me know if that helps 👍

[daviidmorales]

@felangel Thanks for answer me, I need to verify the app version with a version in my backend to restrict the app if it have a lower version, I would like that the verification would be in other bloc.

I'm going to integrate the service to the AuthBloc but I really want to know what do you advise me?

[felangel]

Can you provide a bit more information about why you think the app verification needs to be its own bloc? If you have a pure dart VerificationService you can inject the service into the AuthBloc and do something like:

mapEventToState(event) async* {
  if (event is Authenticate) {
    try {
      bool isValid = await _verificationService.verify();
      if (!isValid) {
        yield AuthenticationFailure();
        return;
      }
      await authenticate();
      yield Authenticated();
    } catch (_) {
      yield AuthenticationFailure();
    }
  }
}

Let me know if that helps 👍

Closing for now but feel free to comment with additional questions/details and I'm happy to continue the conversation. Alternatively, feel free to join gitter to chat.

[daviidmorales]

Thanks for your help @felangel