onTransition method

@override void onTransition(Bloc bloc, Transition transition)

Called whenever a transition occurs in any bloc with the given bloc and transition. A transition occurs when a new event is added and a new state is emitted from a corresponding EventHandler. onTransition is called before a bloc's state has been updated.

Implementation

@override
void onTransition(
  Bloc<dynamic, dynamic> bloc,
  Transition<dynamic, dynamic> transition,
) {
  super.onTransition(bloc, transition);
  assert(() {
    final context = CausalityZone.currentContext();
    TrinityEventBus.instance.emit(CausalEvent(
      parentId: context?.eventId,
      type: CausalEventType.stateChange,
      description: '${bloc.runtimeType}: ${transition.event.runtimeType}',
      metadata: {
        'bloc_type': bloc.runtimeType.toString(),
        'event_type': transition.event.runtimeType.toString(),
        'current_state_type': transition.currentState.runtimeType.toString(),
        'next_state_type': transition.nextState.runtimeType.toString(),
      },
    ));
    return true;
  }());
}