Bloc<Event extends Object?, State extends Object?> class abstract

Takes a Stream of Events as input and transforms them into a Stream of States as output.

Inheritance

• Object
• IBloc<Event, State>
• Bloc

Constructors

Bloc(State initialState)

Takes a Stream of Events as input and transforms them into a Stream of States as output.

Properties

done → Future<void>

Return a future which is completed when the IBlocSink is finished.

no setter, override

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

state → State

The current state.

no setter, override

stream → StateStream<State>

The state stream.

no setter, override

Methods

add(Event event) → void

Notifies the Bloc of a new event If close has already been called, any subsequent calls to add will be ignored and will not result in any subsequent state changes.

override

addError(Object error, [StackTrace? stackTrace]) → void

Reports an error which triggers onError with an optional StackTrace. If close has already been called, any subsequent calls to addError will be ignored and will not result in any subsequent state changes.

override

addStream(Stream<Event> eventStream) → Future<void>

Pass all eventStream events to the Bloc If close has already been called, any subsequent calls to addStream will be ignored and will not result in any subsequent state changes.

override

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.

override

mapEventToState(Event event) → Stream<State>

Must be implemented when a class extends Bloc. mapEventToState is called whenever an event is added and is responsible for converting that event into a new state. mapEventToState can yield zero, one, or multiple states for an event.

inherited

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

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 bloc is updated. onChange is a great spot to add logging/analytics for a specific bloc.

override

onError(Object error, StackTrace stackTrace) → void

Called whenever an error occurs and notifies IBlocObserver.onError.

override

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.

override

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 mapEventToState executed. onTransition is called before a Bloc's state has been updated. A great spot to add logging/analytics at the individual Bloc level.

override

setState(State state) → void

Updates the state to the provided state. setState does nothing if the instance has been closed.

override

toString() → String

A string representation of this object.

inherited

transformEvents(Stream<Event> events, TransitionFunction<Event, State> transitionFn) → Stream<Transition<Event, State>>

Transforms the events stream along with a transitionFn function into a Stream<Transition>. Events that should be processed by mapEventToState need to be passed to transitionFn. By default asyncExpand is used to ensure all events are processed in the order in which they are received. You can override transformEvents for advanced usage in order to manipulate the frequency and specificity with which mapEventToState is called as well as which events are processed.

override

transformTransitions(Stream<Transition<Event, State>> transitions) → Stream<Transition<Event, State>>

Transforms the Stream<Transition> into a new Stream<Transition>. By default transformTransitions returns the incoming Stream<Transition>. You can override transformTransitions for advanced usage in order to manipulate the frequency and specificity at which transitions (state changes) occur.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

observe<R extends Object?>(R body(), {required IBlocObserver observer}) → R

Runs body in its own zone. Observing all BLoC's inside this zone with observer instance.