StateViewModelValueWatcher<T> class

A widget that listens to a StateViewModel and rebuilds itself when the selected parts of the state change.

This widget is typically used with a StateViewModel obtained via readViewModel.

StateViewModelValueWatcher is useful for rebuilding a small part of the UI in response to state changes, without rebuilding the entire widget tree.

It takes a viewModel, a list of selectors, and a builder. The selectors are functions that extract values from the view model's state. The builder is called whenever any of the selected values change.

Example:

final myViewModel = readViewModel<MyViewModel>(factory:
                                                MyViewModelFactory());

StateViewModelValueWatcher<MyState>(
  viewModel: myViewModel,
  selectors: [(state) => state.name, (state) => state.age],
  builder: (state) {
    return Text('Name: ${state.name}, Age: ${state.age}');
  },
)
Inheritance

Constructors

StateViewModelValueWatcher({required List<dynamic Function(T state)> selectors, required Widget builder(T state), required StateViewModel<T> viewModel, Key? key})
const

Properties

builder → Widget Function(T state)
final
hashCode → int
The hash code for this object.
no setterinherited
key → Key?
Controls how one widget replaces another widget in the tree.
finalinherited
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
selectors → List<dynamic Function(T state)>
final
viewModel → StateViewModel<T>
final

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<StatefulWidget>
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