bloc 0.8.4 bloc: ^0.8.4 copied to clipboard
A predictable state management library that helps implement the BLoC (Business Logic Component) design pattern.
import 'package:bloc/bloc.dart';
enum CounterEvent { increment, decrement }
class CounterBloc extends Bloc<CounterEvent, int> {
@override
int get initialState => 0;
@override
Stream<int> mapEventToState(int currentState, CounterEvent event) async* {
switch (event) {
case CounterEvent.decrement:
// Simulating Network Latency
await Future<void>.delayed(Duration(seconds: 1));
yield currentState - 1;
break;
case CounterEvent.increment:
// Simulating Network Latency
await Future<void>.delayed(Duration(milliseconds: 500));
yield currentState + 1;
break;
}
}
}
class SimpleBlocDelegate implements BlocDelegate {
@override
void onTransition(Transition transition) {
print(transition);
}
}
void main() {
BlocSupervisor().delegate = SimpleBlocDelegate();
final counterBloc = CounterBloc();
counterBloc.dispatch(CounterEvent.increment);
counterBloc.dispatch(CounterEvent.increment);
counterBloc.dispatch(CounterEvent.increment);
counterBloc.dispatch(CounterEvent.decrement);
counterBloc.dispatch(CounterEvent.decrement);
counterBloc.dispatch(CounterEvent.decrement);
}