Add extension on BuildContext

[timrijckaert]

Similar to the proposal on the Provider package.
Are we down for some extension functions to easily get a Bloc and a Repository?

var fooBloc = context.bloc<FooBloc>();

var barRepo = context.repo<BarRepo>();

[felangel]

Hey @timrijckaert 👋
Thanks for opening an issue!

I think this is a great idea and there's a lot of potential to improve the of API via extensions. A couple of things I think we need to discuss first are:

1. Doing this would require everyone to use Dart 2.6 which might not be feasible right now given that it's not available for the stable branch (yet).
2. If provider supports this we would get it for free in flutter_bloc. (@rrousselGit)

Thoughts?

[tenhobi]

This feature is for sure something we would love to use, but I would wait for Flutter first, how they use Extensions so we can align to the API etc. Also, because Flutter Bloc uses package:provider, we might, as you say, get those thing for free and it would be better to use their API as well, to make transition from/to provider better. 👍

[timrijckaert]

I agree with all of the above. :)

[larssn]

Extensions would remove quite a bit of boilerplate so I'm all for it. 👍

[arnemolland]

This would be neat indeed. We're currently using a super simple extension:

extension BlocExtension on BuildContext {
  T bloc<T extends Bloc>() {
    return BlocProvider.of<T>(this);
  }
}

Though it may or may not be too simple

[larssn]

@arnemolland It saves a bit of boilerplate, so it's probably fine. 🙂

[felangel]

Added the extensions in #816 and published in v3.2.0 of flutter_bloc 🎉