StateProvider<T> class

A provider that exposes a value that can be modified from outside.

It can be useful for very simple states, like a filter or the currently selected item – which can then be combined with other providers or accessed in multiple screens.

The following code shows a list of products, and allows selecting a product by tapping on it.

final selectedProductIdProvider = StateProvider<String?>((ref) => null);
final productsProvider = StateNotifierProvider<ProductsNotifier, List<Product>>((ref) => ProductsNotifier());

Widget build(BuildContext context, WidgetRef ref) {
  final List<Product> products = ref.watch(productsProvider);
  final selectedProductId = ref.watch(selectedProductIdProvider);

  return ListView(
    children: [
      for (final product in products)
        GestureDetector(
          onTap: () => ref.read(selectedProductIdProvider.notifier).state = product.id,
          child: ProductItem(
            product: product,
            isSelected: selectedProductId.state == product.id,
          ),
        ),
    ],
  );
}

Inheritance

Mixed-in types

AlwaysAliveProviderBase<T>

Available extensions

OverrideWithProviderExtension

Constructors

StateProvider(T _createFn(StateProviderRef<T> ref), {String? name, Iterable<ProviderOrFamily>? dependencies, @Deprecated('Will be removed in 3.0.0') Family<Object?>? from, @Deprecated('Will be removed in 3.0.0') Object? argument, @Deprecated('Will be removed in 3.0.0') DebugGetCreateSourceHash? debugGetCreateSourceHash}): A provider that exposes a value that can be modified from outside.
StateProvider.internal(T _createFn(StateProviderRef<T> ref), {required String? name, required Iterable<ProviderOrFamily>? dependencies, required Iterable<ProviderOrFamily>? allTransitiveDependencies, required DebugGetCreateSourceHash? debugGetCreateSourceHash, Family<Object?>? from, Object? argument}): An implementation detail of Riverpod

Properties

allTransitiveDependencies → Iterable<ProviderOrFamily>?: All the dependencies of a provider and their dependencies too.
finalinherited
argument → Object?: If this provider was created with the .family modifier, argument is the variable that was used.
finalinherited
debugGetCreateSourceHash → DebugGetCreateSourceHash?: A debug-only fucntion for obtaining a hash of the source code of the initialization function.
finalinherited
dependencies → Iterable<ProviderOrFamily>?: The list of providers that this provider potentially depends on.
finalinherited
from → Family<Object?>?: If this provider was created with the .family modifier, from is the .family instance.
finalinherited
hashCode → int: The hash code for this object.
no setterinherited
name → String?: A custom label for providers.
finalinherited
notifier → AlwaysAliveRefreshable<StateController<T>>: latefinal
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
state → AlwaysAliveRefreshable<StateController<T>>: latefinal

Methods

addListener(Node node, void listener(T? previous, T next), {required void onError(Object error, StackTrace stackTrace)?, required void onDependencyMayHaveChanged()?, required bool fireImmediately}) → ProviderSubscription<T>: Starts listening to this transformer
inherited
createElement() → StateProviderElement<T>: An internal method that defines how a provider behaves.
override
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
overrideWith(Create<T, StateProviderRef<T>> create) → Override: Override the provider with a new initialization function.
read(Node node) → T: Obtains the result of this provider expression without adding listener.
inherited
select<Selected>(Selected selector(T value)) → AlwaysAliveProviderListenable<Selected>: Partially listen to a provider.
inherited
toString() → String: A string representation of this object.
inherited

Operators

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

Constants

autoDispose → const AutoDisposeStateProviderBuilder: Marks the provider as automatically disposed when no longer listened to.
family → const StateProviderFamilyBuilder: A group of providers that builds their value from an external parameter.