StateProvider<T> class
A provider that expose a value which 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>((ref) => ProductsNotifier());
Widget build(BuildContext context, ScopedReader watch) {
final List<Product> products = watch(productsProvider);
final selectedProductId = watch(selectedProductIdProvider);
return ListView(
children: [
for (final product in products)
GestureDetector(
onTap: () => selectedProductId.state = product.id,
child: ProductItem(
product: product,
isSelected: selectedProductId.state == product.id,
),
),
],
);
}
- Inheritance
-
- Object
- ProviderBase<
StateController< T> , StateController<T> > - RootProvider<
StateController< T> , StateController<T> > - AlwaysAliveProviderBase<
StateController< T> , StateController<T> > - StateProvider
- Annotations
-
- @sealed
Constructors
-
StateProvider(Create<
T, ProviderReference> _create, {String? name}) - A provider that expose a value which can be modified from outside.
Properties
- argument → Object?
-
If this provider was created with the
.family
modifier, argument is variable used.no setterinherited - debugId ↔ String
-
A unique identifier for this provider, used by devtools to differentiate providers
latefinalinherited
-
from
→ Family<
dynamic, dynamic, dynamic, ProviderReference, RootProvider> ? -
If this provider was created with the
.family
modifier, from is the.family
instance.no setterinherited - hashCode → int
-
The hash code for this object.
no setterinherited
- name → String?
-
A custom label for providers.
finalinherited
-
notifier
→ AlwaysAliveProviderBase<
StateController< T> , StateController<T> > -
Obtains the
StateController
associated with this provider, but without listening to it.latefinal - runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
Methods
-
create(
ProviderReference ref) → StateController< T> -
override
-
createElement(
) → ProviderElement< StateController< T> , StateController<T> > -
An internal method that defines how a provider behaves.
inherited
-
createState(
) → _StateProviderState< T> -
An internal method that creates the state of a provider.
override
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
overrideWithProvider(
AlwaysAliveProviderBase< Object?, StateController< provider) → ProviderOverrideT> > -
Overrides the behavior of this provider with another provider.
inherited
-
overrideWithValue(
StateController< T> value) → Override -
Overrides the behavior of a provider with a value.
inherited
-
select<
Selected> (Selected selector(StateController< T> value)) → ProviderListenable<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.
- family → const StateProviderFamilyBuilder
- A group of providers that builds their value from an external parameter.