ReactiveBuilder<T> class

A widget that rebuilds when a reactive variable changes.

ReactiveBuilder automatically listens to a Reactive variable and rebuilds its child widget whenever the variable's value changes. This provides a declarative way to create reactive UI without manually managing listeners.

The widget is lightweight and efficient, using Flutter's ValueListenableBuilder internally for optimal performance.

Example:

final counter = Reactive<int>(0);

ReactiveBuilder<int>(
  reactiv: counter,
  builder: (context, count) {
    return Text('Count: $count');
  },
  listener: (count) {
    debugPrint('Count changed to $count');
  },
  buildWhen: (prev, current) => current % 2 == 0, // Only rebuild on even numbers
  listenWhen: (prev, current) => current > 10,     // Only listen when > 10
);

// Updates automatically when counter changes
counter.value++;

For multiple reactive variables, use ReactiveBuilderN instead.

Inheritance

Constructors

ReactiveBuilder({Key? key, required Reactive<T> reactiv, required Widget builder(BuildContext context, T value), void listener(T value)?, bool buildWhen(T previous, T current)?, bool listenWhen(T previous, T current)?})
Creates a ReactiveBuilder widget.
const

Properties

builder → Widget Function(BuildContext context, T value)
Builder function called with the current value whenever it changes.
final
buildWhen → bool Function(T previous, T current)?
Optional condition to determine whether the widget should rebuild.
final
hashCode → int
The hash code for this object.
no setterinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
listener → void Function(T value)?
Optional listener function called whenever the value changes.
final
listenWhen → bool Function(T previous, T current)?
Optional condition to determine whether the listener should be invoked.
final
reactiv → Reactive<T>
The reactive variable to observe for changes.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<ReactiveBuilder<T>>
Creates the mutable state for this widget at a given location in the tree.
override
debugDescribeChildren() → List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children.
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node.
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toDiagnosticsNode({String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep.
inherited
toString({DiagnosticLevel minLevel = DiagnosticLevel.info}) → String
A string representation of this object.
inherited
toStringDeep({String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → String
Returns a string representation of this node and its descendants.
inherited
toStringShallow({String joiner = ', ', DiagnosticLevel minLevel = DiagnosticLevel.debug}) → String
Returns a one-line detailed description of the object.
inherited
toStringShort() → String
A short, textual description of this widget.
inherited

Operators

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