ReactiveSubject<T> class

A wrapper class for RxDart subjects that provides a simplified interface for reactive programming.

This class encapsulates either a BehaviorSubject or a PublishSubject and provides methods to interact with the underlying subject in a more convenient way.

Usage:

// Create a ReactiveSubject with an initial value
final subject = ReactiveSubject<int>(initialValue: 0);

// Add a value
subject.add(1);

// Listen to the stream
subject.stream.listen((value) => print(value));

// Get the current value
print(subject.value);

// Dispose when done
subject.dispose();

Usage with StreamBuilder in a widget:

class MyWidget extends StatefulWidget {
  @override
  _MyWidgetState createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> {
  final ReactiveSubject<int> _counter = ReactiveSubject<int>(initialValue: 0);

  @override
  void dispose() {
    _counter.dispose();
    super.dispose();
  }

  void _incrementCounter() {
    _counter.add(_counter.value + 1);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: StreamBuilder<int>(
          stream: _counter.stream,
          builder: (context, snapshot) {
            if (snapshot.hasData) {
              return Text('Counter: ${snapshot.data}');
            } else {
              return CircularProgressIndicator();
            }
          },
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        child: Icon(Icons.add),
      ),
    );
  }
}

Available extensions

Constructors

ReactiveSubject({T? initialValue}): Creates a ReactiveSubject with a BehaviorSubject.
ReactiveSubject.broadcast({T? initialValue}): Creates a ReactiveSubject with a PublishSubject.

Properties

hashCode → int: The hash code for this object.
no setterinherited
hasValue → bool: Returns true if the subject has a current value.
no setter
isClosed → bool: Whether the underlying subject is closed.
no setter
isDisposed → bool: Checks if the subject has been disposed
no setter
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
sink → Sink<T>: The sink of the underlying subject.
no setter
stream → Stream<T>: The stream of the underlying subject.
no setter
value → T: The current value of the subject.
no setter
valueOrNull → T?: Returns the current value if available, otherwise returns null. This is a safe alternative to value that doesn't throw exceptions.
no setter

Methods

add(T value) → void: Adds a new value to the subject with disposal check
addError(Object error, [StackTrace? stackTrace]) → void: Adds an error to the subject.
buffer(Stream closing) → ReactiveSubject<List<T>>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectTimeControlExtension extension
Buffers values from the source ReactiveSubject until the closing stream emits.
cache() → ReactiveSubject<T>: Caches the latest value and replays it to new subscribers. This is more memory efficient than shareReplay for single value caching.
debounceTime(Duration duration) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectTimeControlExtension extension
Emits items from the source ReactiveSubject only after a specified duration has passed without the ReactiveSubject emitting any other items.
debug({String? tag, void onValue(T value)?, void onError(Object error)?}) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectUtilitiesExtension extension
Adds debugging capabilities to the ReactiveSubject by logging events.
dispose() → Future<void>: Disposes the subject and prevents further usage
distinct([bool equals(T previous, T next)?]) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectStateManagementExtension extension
Emits all items emitted by the source ReactiveSubject that are distinct from their immediate predecessors.
distinctBy<K>(K keySelector(T value)) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectStateManagementExtension extension
Emits items that are distinct based on a key selector function. This is more efficient than distinct() when you only need to compare specific properties.
doOnData(void onData(T event)) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectUtilitiesExtension extension
Performs a side-effect action for each data event emitted by the source ReactiveSubject.
doOnError(void onError(Object error, StackTrace stackTrace)) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectUtilitiesExtension extension
Performs a side-effect action for each error event emitted by the source ReactiveSubject.
groupBy<K>(K keySelector(T value)) → ReactiveSubject<Map<K, List<T>>>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectStateManagementExtension extension
Groups stream events into separate lists based on a key selector function.
listen(void onData(T value), {Function? onDone, Function? onError, bool? cancelOnError}) → StreamSubscription<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectUtilitiesExtension extension
Listens to the stream and calls the provided callbacks.
listenManaged(void onData(T value), {Function? onDone, Function? onError, bool? cancelOnError}) → StreamSubscription<T>: Creates a managed subscription that will be automatically cancelled on dispose
map<R>(R mapper(T event)) → ReactiveSubject<R>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectTransformationsExtension extension
Transforms the items emitted by the source ReactiveSubject by applying a function to each item.
mapNotNull<R>(R? mapper(T event)) → ReactiveSubject<R>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectTransformationsExtension extension
Transforms each item emitted by the source ReactiveSubject by applying a function that returns a nullable value, and only emits non-null results.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
onErrorResumeNext(ReactiveSubject<T> recoveryFn(Object error)) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectErrorHandlingExtension extension
Catches errors from the source ReactiveSubject and executes a recovery function to continue the stream.
pairwise() → ReactiveSubject<List<T>>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectUtilitiesExtension extension
Emits the previous and current values as a pair.
retry([int? count]) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectErrorHandlingExtension extension
Retries the source ReactiveSubject when an error occurs.
retryWhen(Stream<void> retryWhenFactory(Stream<Object>)) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectErrorHandlingExtension extension
Retries the source ReactiveSubject when an error occurs, with a delay between retries.
scan<R>(R initialValue, R accumulator(R accumulated, T current, int index)) → ReactiveSubject<R>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectCombinationsExtension extension
Applies an accumulator function over the source ReactiveSubject, and returns each intermediate result as a ReactiveSubject.
share() → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectStateManagementExtension extension
Shares a single subscription to the source ReactiveSubject among multiple subscribers.
shareReplay({int maxSize = 1}) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectStateManagementExtension extension
Shares a single subscription and replays the specified number of latest values to new subscribers.
skipLast(int count) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectUtilitiesExtension extension
Skips the last count items emitted by the source ReactiveSubject.
startWith(T startValue) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectCombinationsExtension extension
Prepends a given value to the source ReactiveSubject.
switchMap<R>(ReactiveSubject<R> mapper(T event)) → ReactiveSubject<R>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectTransformationsExtension extension
Transforms the items emitted by the source ReactiveSubject by applying a function that returns a ReactiveSubject, then emitting the items emitted by the most recently created ReactiveSubject.
takeLast(int count) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectUtilitiesExtension extension
Takes the last count items emitted by the source ReactiveSubject.
takeWhileInclusive(bool test(T event)) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectUtilitiesExtension extension
Emits items from the source ReactiveSubject while the test function returns true. Unlike Stream.takeWhile, this includes the first item that fails the test.
throttleTime(Duration duration) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectTimeControlExtension extension
Emits the first item emitted by the source ReactiveSubject in each time window of a specified duration.
timeInterval() → ReactiveSubject<TimeInterval<T>>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectUtilitiesExtension extension
Emits the time interval between consecutive emissions.
timestamp() → ReactiveSubject<Timestamped<T>>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectUtilitiesExtension extension
Emits each item with a timestamp indicating when it was emitted.
toString() → String: A string representation of this object.
inherited
valueOr(T defaultValue) → T: Returns the current value if available, otherwise returns the provided default value.
where(bool test(T event)) → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectTransformationsExtension extension
Filters the items emitted by the source ReactiveSubject by only emitting those that satisfy a specified predicate.
whereNotNull() → ReactiveSubject<T>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectTransformationsExtension extension
Emits only items that are not null from the source ReactiveSubject.
withLatestFrom<S, R>(ReactiveSubject<S> other, R combiner(T event, S latestFromOther)) → ReactiveSubject<R>: Available on ReactiveSubject<T>, provided by the ReactiveSubjectCombinationsExtension extension
Combines the latest values of two ReactiveSubjects using a specified combiner function.

Operators

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

Static Methods

combineLatest<T>(List<ReactiveSubject<T>> subjects) → ReactiveSubject<List<T>>: Combines the latest values of multiple ReactiveSubjects into a single ReactiveSubject that emits a List of those values.
fromFutureWithError<T>(Future<T> future, {dynamic onError(Object error)?, dynamic onFinally()?, Duration? timeout}) → ReactiveSubject<T>: Creates a ReactiveSubject from a Future, with error handling and completion callback.
merge<T>(List<ReactiveSubject<T>> subjects) → ReactiveSubject<T>: Merges multiple ReactiveSubjects into a single ReactiveSubject.