IfLetStore<S, A> class

A widget that conditionally renders content based on nullable state.

When the store's state is non-null, builder is called with a non-nullable Store<S, A>. When the state is null, orElse is rendered (or SizedBox.shrink if not provided).

Only rebuilds when the null/non-null status changes, not on every state change within the non-null branch.

Example

IfLetStore<UserProfile, ProfileAction>(
  store: profileStore, // Store<UserProfile?, ProfileAction>
  builder: (context, store) => WithStore(
    store: store,
    builder: (profile, send, ctx) => Text(profile.name),
  ),
  orElse: (context) => Text('No profile'),
);

With State Projection

IfLetStore.observe(
  store: appStore,
  toNullableState: (state) => state.selectedUser,
  toGlobalAction: (action) => AppAction.user(action),
  builder: (context, store) => UserDetailView(store: store),
);

Inheritance

Constructors

IfLetStore({Key? key, required Store<S?, A> store, required Widget builder(BuildContext context, Store<S, A> store), Widget orElse(BuildContext context)?}): Creates an IfLetStore with a nullable state store.
const

Properties

builder → Widget Function(S? state, void send(A), BuildContext context): Builder function called on every state change.
finalinherited
hashCode → int: The hash code for this object.
no setterinherited
isEqual → bool Function(S? previous, S? current): Equality function to determine whether a state change should trigger a rebuild. Defaults to ==.
finalinherited
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
orElse → Widget Function(BuildContext context)?: Widget to render when the state is null.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
store → Store<S?, A>: The store whose state drives this widget's rebuilds.
finalinherited

Methods

build(BuildContext context) → Widget: Describes the part of the user interface represented by this widget.
override
createElement() → StatelessElement: Creates a StatelessElement to manage this widget's location in the tree.
inherited
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

Static Methods

createBuilder<S, A>(Widget builder(BuildContext context, Store<S, A> store), Widget orElse(BuildContext context)?, Store<S?, A> store) → dynamic: Creates the internal builder that handles null/non-null branching.
observe<GlobalState, NullableState, GlobalAction, A>({Key? key, required Store<GlobalState, GlobalAction> store, required Widget builder(BuildContext context, Store<NullableState, A> store), required NullableState? toNullableState(GlobalState state), required GlobalAction toGlobalAction(A action), Widget orElse(BuildContext context)?}) → IfLetStore<NullableState, A>: Creates an IfLetStore by projecting nullable state from a global store.
override