extending extended class or how to get code out of BLoC - flutter

Question

since one cannot extend an extension of a class such as class MyBloc extends Bloc<MyEvent, MyState>, what is a cleanest way to get some functions out of my bloc file? Since the logic is a bit more complex, I would like to get some sub functions out like in
#override
Stream<MyState> mapEventToState(MyEvent event) async* {
yield* event.map(
loadRequested: (e) => _mapLoadRequestedToState(),
dataEntered: (e) => _mapDataEnteredToState(),
);
}
Stream<LogicChainState> _mapLoadRequestedToState() async* {
final dataRaw = loadData();
final dataProc = initData(dataRaw);
yield doSomeMore(dataProc);
}
I don't like the idea of using global functions. I could create a class
class MyBlocUtils {
MyData initData(MyData dataRaw) {
...
}
MyData doSomeMore(MyData dataProc) {
...
}
}
which still isn't as nice as using a function defined within the class MyBloc.
Any advice?

Answer 1

If all you want is to separate your methods into multiple files, but keep them in the same class, you could use extension methods.
my_bloc.dart
part 'my_bloc_utils.dart';
class MyBloc extends Bloc<MyEvent, MyState> {
Stream<LogicChainState> _mapLoadRequestedToState() async* {
final dataRaw = loadData();
final dataProc = initData(dataRaw);
yield doSomeMore(dataProc);
}
}
my_bloc_utils.dart
part of 'my_bloc.dart';
extension MyBlocUtils on MyBloc {
#override
Stream<MyState> mapEventToState(MyEvent event) async* {
yield* event.map(
loadRequested: (e) => _mapLoadRequestedToState(),
dataEntered: (e) => _mapDataEnteredToState(),
);
}
}
You can access the methods in just the same way as you keep everything in a single file:
import 'my_bloc.dart';
final myBloc = MyBloc();
final stream = myBloc.mapEventToState(MyEvent());