HydratedBloc<Event, State> class abstract

Specialized Bloc which handles initializing the Bloc state based on the persisted state. This allows state to be persisted across hot restarts as well as complete app restarts.

abstract class CounterEvent {}
class CounterIncrementPressed extends CounterEvent {}
class CounterDecrementPressed extends CounterEvent {}

class CounterBloc extends HydratedBloc<CounterEvent, int> {
  CounterBloc() : super(0) {
    on<CounterIncrementPressed>((event, emit) => emit(state + 1));
    on<CounterDecrementPressed>((event, emit) => emit(state - 1));
  }

  @override
  int fromJson(Map<String, dynamic> json) => json['value'] as int;

  @override
  Map<String, int> toJson(int state) => {'value': state};
}

Inheritance

Object
BlocBase<State>
Bloc<Event, State>
HydratedBloc

Mixed-in types

HydratedMixin<State>

Constructors

HydratedBloc(State state, {Storage? storage, OnHydrationError onHydrationError = defaultOnHydrationError}): Specialized Bloc which handles initializing the Bloc state based on the persisted state. This allows state to be persisted across hot restarts as well as complete app restarts.

Properties

hashCode → int: The hash code for this object.
no setterinherited
id → String: id is used to uniquely identify multiple instances of the same HydratedBloc type. In most cases it is not necessary; however, if you wish to intentionally have multiple instances of the same HydratedBloc, then you must override id and return a unique identifier for each HydratedBloc instance in order to keep the caches independent of each other.
no setterinherited
isClosed → bool: Whether the bloc is closed.
no setterinherited
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
state → State: The current state.
no setterinherited
storagePrefix → String: Storage prefix which can be overridden to provide a custom storage namespace. Defaults to runtimeType but should be overridden in cases where stored data should be resilient to obfuscation, minification or persist between debug/release builds.
no setterinherited
storageToken → String: storageToken is used as registration token for hydrated storage. Composed of storagePrefix and id.
no setterinherited
stream → Stream<State>: The current stream of states.
no setterinherited

Methods

add(Event event) → void: Notifies the Bloc of a new event which triggers all corresponding EventHandler instances.
inherited
addError(Object error, [StackTrace? stackTrace]) → void: Reports an error which triggers onError with an optional StackTrace.
inherited
clear() → Future<void>: clear is used to wipe or invalidate the cache of a HydratedBloc. Calling clear will delete the cached state of the bloc but will not modify the current state of the bloc.
inherited
close() → Future<void>: Closes the event and state Streams. This method should be called when a Bloc is no longer needed. Once close is called, events that are added will not be processed. In addition, if close is called while events are still being processed, the Bloc will finish processing the pending events.
inherited
emit(State state) → void: emit is only for internal use and should never be called directly outside of tests. The Emitter instance provided to each EventHandler should be used instead.
inherited
fromJson(Map<String, dynamic> json) → State?: Responsible for converting the Map<String, dynamic> representation of the bloc state into a concrete instance of the bloc state.
inherited
hydrate({Storage? storage, OnHydrationError onError = defaultOnHydrationError}) → void: Populates the internal state storage with the latest state. This should be called when using the HydratedMixin directly within the constructor body.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
on<E extends Event>(EventHandler<E, State> handler, {EventTransformer<E>? transformer}) → void: Register event handler for an event of type E. There should only ever be one event handler per event type E.
inherited
onChange(Change<State> change) → void: Called whenever a change occurs with the given change. A change occurs when a new state is emitted. onChange is called before the state of the cubit is updated. onChange is a great spot to add logging/analytics for a specific cubit.
inherited
onDone(Event event, [Object? error, StackTrace? stackTrace]) → void: Called whenever an event handler for a specific Bloc has completed. This may include an error and stackTrace if an uncaught exception occurred within the event handler.
inherited
onError(Object error, StackTrace stackTrace) → void: Called whenever an error occurs and notifies BlocObserver.onError.
inherited
onEvent(Event event) → void: Called whenever an event is added to the Bloc. A great spot to add logging/analytics at the individual Bloc level.
inherited
onTransition(Transition<Event, State> transition) → void: Called whenever a transition occurs with the given transition. A transition occurs when a new event is added and a new state is emitted from a corresponding EventHandler.
inherited
toJson(State state) → Map<String, dynamic>?: Responsible for converting a concrete instance of the bloc state into the the Map<String, dynamic> representation.
inherited
toString() → String: A string representation of this object.
inherited

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Static Properties

storage ↔ Storage: Instance of Storage which will be used to manage persisting/restoring the Bloc state.
getter/setter pair