built_bloc
Generate the BLoC pattern boilerplate.
Why ?
After using the BLoC pattern a little, it seems pretty cool for sharing code and separation of concerns, but I quickly found myself to write a lot of repetitive boilerplate code : I felt the need for a generator to assist me.
Here is a simple vanilla bloc example which obviously highlights repeated patterns while declaring subjects, streams, sinks and subscriptions.
class VanillaExampleBloc {
Sink<void> get reset => this._reset.sink;
Sink<int> get add => this._add.sink;
Stream<int> get count => this._count.stream;
final PublishSubject<int> _add = PublishSubject<int>();
final PublishSubject<void> _reset = PublishSubject<void>();
final BehaviorSubject<int> _count = BehaviorSubject<int>.seeded(0);
List<StreamSubscription> subscriptions;
List<Subject> subjects;
VanillaExampleBloc() {
subscriptions = [
this._add.listen(_onAdd),
this._reset.listen(_onReset),
];
subjects = [
this._add,
this._count,
this._reset,
];
}
void _onAdd(int value) {
this._count.add(this._count.value + value);
}
void _onReset(int value) {
this._count.add(0);
}
@mustCallSuper
void dispose() {
this.subjects.forEach((s) => s.close());
this.subscriptions.forEach((s) => s.cancel());
}
}With built_bloc, you can replace all of that with just a few lines of code :
@bloc
class ExampleBloc extends Bloc with _ExampleBloc {
@stream
final BehaviorSubject<int> _count = BehaviorSubject<int>(seedValue: 0);
@sink
@Bind("_onAdd")
final PublishSubject<int> _add = PublishSubject<int>();
@sink
@Bind("_onReset")
final PublishSubject<void> _reset = PublishSubject<void>();
void _onAdd(int value) {
this._count.add(this._count.value + value);
}
void _onReset() {
this._count.add(0);
}
}How to use ?
See the built_bloc_generator package.