RxComputed<T> class

A reactive computed value that automatically tracks dependencies.

RxComputed automatically re-evaluates when any of its dependent RxState or field-level dependencies change.

Features:

  • Automatic dependency tracking (state + field-level)
  • Lazy recomputation on dependency change
  • Read-only reactive value (cannot be set manually)
final a = RxState<int>(1);
final b = RxState<int>(2);
final sum = RxComputed<int>(() => a.value + b.value);

sum.listen((val) => print('sum = $val'));
a.value = 3; //  sum = 5
Inheritance
Available extensions

Constructors

RxComputed(T compute())
Creates a computed reactive value.

Properties

compute → T Function()
The computation function used to derive the value.
final
current → T

Available on RxComputed<T>, provided by the RxComputedExtensions extension

no setter
hashCode → int
The hash code for this object.
no setterinherited
id → dynamic
Unique identifier for debugging or tracking updates in listenWithId.
finalinherited
isEmpty → bool

Available on RxState<List<T>>, provided by the RxListToState extension

Whether the list is empty.
no setter
isNotEmpty → bool

Available on RxState<List<T>>, provided by the RxListToState extension

Whether the list is not empty.
no setter
length → int

Available on RxState<List<T>>, provided by the RxListToState extension

The number of elements in the list.
no setter
name → String?
A human-readable name, mainly used for logging and debugging output.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
v → T

Available on RxComputed<T>, provided by the RxComputedExtensions extension

Returns the current computed value.
no setter
value ↔ T
Gets the current value and automatically triggers dependency tracking in RxStack.
getter/setter pairinherited-getteroverride-setter

Methods

add(T element) → void

Available on RxState<List<T>>, provided by the RxListToState extension

Adds an element to the list and triggers a refresh.
addFieldListener(dynamic field, void listener(dynamic)) → void
Adds a field-level listener.
inherited
addListener(void listener(dynamic)) → void
Adds a global listener.
inherited
addListenerWithId(void listener(dynamic)) → void
Adds a listener that also receives the state id.
inherited
bind(void onUpdate(T value)) → void Function()
Binds a listener to the state.
inherited
contains(T element) → bool

Available on RxState<List<T>>, provided by the RxListToState extension

Returns whether the list contains the given element.
deepEquals(dynamic a, dynamic b) → bool
inherited
dispose() → void
Disposes all dependency listeners.
override
getItem(dynamic field) → dynamic
Gets a specific field or index from a collection.
inherited
internalUpdate(T newValue) → void
Internal update used by computed or framework-level mechanisms. It updates the value and triggers global listeners if the value changes.
inherited
listen(void onData(T value)) → void Function()
Listens to value changes and immediately emits the current value.
inherited
listenByKey(dynamic key, void onData(dynamic)) → void Function()
Listens to a specific key in a Map or index in a List.
inherited
listenWhere(bool test(dynamic item), void onData(dynamic)) → void Function()
Conditional listener.
inherited
listenWithId(void onData(T value, dynamic id)) → void Function()
Listens to value changes and provides both value and state id.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
notifyField(dynamic field) → void
Notifies all listeners registered for a specific field.
inherited
refresh() → void
Manually triggers a refresh.
inherited
remove(T element) → void

Available on RxState<List<T>>, provided by the RxListToState extension

Removes an element from the list and triggers a refresh.
removeFieldListener(dynamic field, void listener(dynamic)) → void
Removes a field-level listener.
inherited
removeListener(void listener(dynamic)) → void
Removes a global listener.
inherited
runAsync({required Future<T> asyncAction(), void onLoading(bool loading)?, void onError(Object error)?, int retryCount = 3, Duration retryDelay = const Duration(seconds: 2)}) → Future<void>
Executes an asynchronous action with automatic retry support.
inherited
runAsyncWithStatus({required Future<T> asyncAction(), void onLoading(bool loading)?, void onError(Object error)?}) → Future<void>
Executes an asynchronous action and updates the state.
inherited
toString() → String
A string representation of this object.
inherited
update(dynamic newValue) → void
Updates the entire state or attempts a type-conversion update.
inherited
updateField<K extends Object>(K field, Object? newValue) → void
Updates a specific key in a Map or an index in a List.
inherited

Operators

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