BlocSelector<B extends StateStreamable<S>, S, T> class

BlocSelector is analogous to BlocBuilder but allows developers to filter updates by selecting a new value based on the bloc state. Unnecessary builds are prevented if the selected value does not change.

Note: the selected value must be immutable in order for BlocSelector to accurately determine whether builder should be called again.

BlocSelector<BlocA, BlocAState, SelectedState>(
  selector: (state) {
    // return selected state based on the provided state.
  },
  builder: (context, state) {
    // return widget here based on the selected state.
  },
)
Inheritance

Constructors

BlocSelector({required BlocWidgetSelector<S, T> selector, required BlocWidgetBuilder<T> builder, Key? key, B? bloc})
BlocSelector is analogous to BlocBuilder but allows developers to filter updates by selecting a new value based on the bloc state. Unnecessary builds are prevented if the selected value does not change.
const

Properties

bloc → B?
The bloc that the BlocSelector will interact with. If omitted, BlocSelector will automatically perform a lookup using BlocProvider and the current BuildContext.
final
builder → BlocWidgetBuilder<T>
The builder function which will be invoked when the selected state changes. The builder takes the BuildContext and selected state and must return a widget. This is analogous to the builder function in BlocBuilder.
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
selector → BlocWidgetSelector<S, T>
The selector function which will be invoked on each widget build and is responsible for returning a selected value of type T based on the current state.
final

Methods

createElement() → StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() → State<BlocSelector<B, S, 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.
override
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}) → 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