BaseBloc class abstract

Base bloc class that provides network request management with automatic cancellation.

Features:

  • Automatically creates and tracks CancelTokens for all network requests
  • Cancels all pending requests when the bloc is disposed/closed
  • Prevents memory leaks and unnecessary API calls when user navigates away

Usage:

// 1. Update repository method to accept CancelToken:
Future<DataModel> getData({CancelToken? cancelToken}) async {
  var response = await NetworkProvider().request(
    Api.endpoint,
    method: HTTPMethod.get,
    cancelToken: cancelToken, // Pass the token
  );
  return DataModel.fromJson(response);
}

// 2. Update bloc to pass CancelToken:
await networkRequest(
  (CancelToken cancelToken) async => await _repo.getData(cancelToken: cancelToken),
  onSuccess: (response) {
    // Handle success
  },
);

When the bloc is disposed, all pending requests are automatically cancelled.

Implementers

Constructors

BaseBloc({BaseStates? initialState})

Properties

errorController ↔ StreamController
getter/setter pair
hashCode → int
The hash code for this object.
no setterinherited
isClosed → bool
Whether the bloc is closed.
no setterinherited
loadingController ↔ StreamController
getter/setter pair
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
state → BaseStates
The current state.
no setterinherited
stream → Stream<BaseStates>
The current stream of states.
no setterinherited

Methods

add(BaseEvent 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
cancelAllRequests() → void
Cancels all active requests. This is automatically called when the bloc is disposed/closed.
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.
createCancelToken() → CancelToken
Creates a new CancelToken and adds it to the list of active tokens. This token should be passed to repository methods that accept CancelToken.
dispose() → void
emit(BaseStates 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
handleResponse<T>(dynamic error, Future<T> request(CancelToken cancelToken), {bool showLoadingBar = true, bool showProgress = false, dynamic onSuccess, FutureOr<void> handleErrorCode(dynamic)?}) → Future<void>
networkLoadRequest<T>(Future<T> request(CancelToken cancelToken), {required Future onSuccess(T response), bool showLoadingBar = true, bool showProgress = false, FutureOr<void> handleError(dynamic)?, dynamic errorAction()?, CancelToken? cancelToken}) → Future<T?>
networkRequest<T>(Future<T> request(CancelToken cancelToken), {required dynamic onSuccess(T response), bool showLoadingBar = true, bool showProgress = false, FutureOr<void> handleError(dynamic)?, FutureOr<void> handleErrorCode(dynamic)?, dynamic errorAction()?, CancelToken? cancelToken, dynamic handleErrorMessage(T response)?}) → Future<T?>
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
on<E extends Event>(EventHandler<E, BaseStates> 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<BaseStates> 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(BaseEvent 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(BaseEvent 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<BaseEvent, BaseStates> 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
showLoading() → void
startListener() → void
toString() → String
A string representation of this object.
inherited

Operators

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