CurrentValueSubject<T> class

An Observable that holds a current value and notifies listeners when the value changes.

This is the concrete implementation of Observable used internally by Store to manage state and action streams.

Creating a Subject

final subject = CurrentValueSubject.create<int>(0);
subject.listen((value) => print(value)); // prints 0 immediately
subject.add(1); // prints 1

Create a derived subject that projects a subset of the value:

final name = subject.derive((user) => user.name);

Inheritance

hashCode → int: The hash code for this object.
no setterinherited
listeners ↔ List<Listener<T>>: getter/setter pair
onCancel ← void Function(): Sets the cancellation callback. Can only be set once.
no getter
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
value → T: The current value held by this subject.
no setter

add(T value) → void: Emits a new value to all listeners.
cancel(int id) → void: Cancels a subscription by its id, as returned from listen.
override
derive<Derived>(Derived deriveState(T state)) → CurrentValueSubject<Derived>: Creates a derived subject that projects a subset of this subject's value.
dispose() → void: Removes all listeners and clears the cancellation callback.
distinct([bool isEqual(T a, T b)?]) → Observable<T>: Returns an observable that only emits when the value changes according to isEqual (defaults to ==).
inherited
listen(OnChangeCallback<T> callback, {bool fireImmediately = true}) → int: Subscribes to value changes.
override
map<R>(R transform(T value)) → Observable<R>: Returns an observable that transforms each emitted value using transform.
inherited
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toString() → String: A string representation of this object.
inherited
when(bool predicate(T value)) → Observable<T>: Returns an observable that only emits values satisfying predicate.
inherited

create<T>(T value) → CurrentValueSubject<T>: Creates a subject with an initial value.
empty<T>() → CurrentValueSubject<T>: Creates a subject without an initial value.