AutoDisposeFutureProvider<State> class Null safety

A provider that asynchronously creates a single value.

FutureProvider can be considered as a combination of Provider and FutureBuilder. By using FutureProvider, the UI will be able to read the state of the future synchronously, handle the loading/error states, and rebuild when the future completes.

A common use-case for FutureProvider is to represent an asynchronous operation such as reading a file or making an HTTP request, that is then listened by the UI.

It can then be combined with:

Usage example: reading a configuration file

FutureProvider can be a convenient way to expose a Configuration object created by reading a JSON file.

Creating the configuration would be done with your typical async/await syntax, but inside the provider. Using Flutter's asset system, this would be:

final configProvider = FutureProvider<Configuration>((ref) async {
  final content = json.decode(
    await rootBundle.loadString('assets/configurations.json'),
  ) as Map<String, Object?>;

  return Configuration.fromJson(content);
});

Then, the UI can listen to configurations like so:

Widget build(BuildContext context, WidgetRef ref) {
  AsyncValue<Configuration> config = ref.watch(configProvider);

  return config.when(
    loading: () => const CircularProgressIndicator(),
    error: (err, stack) => Text('Error: $err'),
    data: (config) {
      return Text(config.host);
    },
  );
}

This will automatically rebuild the UI when the Future completes.

As you can see, listening to a FutureProvider inside a widget returns an AsyncValue – which allows handling the error/loading states.

See also:

Inheritance
Annotations

Constructors

AutoDisposeFutureProvider(Create<FutureOr<State>, AutoDisposeFutureProviderRef<State>> _create, {String? name, List<ProviderOrFamily>? dependencies, Family<dynamic, dynamic, ProviderBase>? from, Object? argument})
A provider that asynchronously creates a single value. [...]

Properties

allTransitiveDependencies List<ProviderOrFamily>?
All the dependencies of a provider and their dependencies too.
late, final, inherited
argument Object?
If this provider was created with the .family modifier, argument is variable used.
final, inherited
dependencies List<ProviderOrFamily>?
The list of providers that this provider potentially depends on. [...]
final
from Family<dynamic, dynamic, ProviderBase>?
If this provider was created with the .family modifier, from is the .family instance.
final, inherited
future AutoDisposeProviderBase<Future<State>>
A provider that exposes the Future created by a FutureProvider. [...]
late, final
hashCode int
The hash code for this object. [...]
read-only, inherited
name String?
A custom label for providers. [...]
final, inherited
originProvider ProviderBase<AsyncValue<State>>
The provider that will be refreshed when calling ProviderContainer.refresh and that will be overridden when passed to ProviderScope. [...]
read-only, override
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited

Methods

create(covariant AutoDisposeFutureProviderElement<State> ref) AsyncValue<State>
Initializes the state of a provider
override
createElement() → AutoDisposeFutureProviderElement<State>
An internal method that defines how a provider behaves.
override
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
inherited
overrideWithProvider(AutoDisposeProviderBase<AsyncValue<State>> value) Override
Overrides a provider with a value, ejecting the default behaviour. [...]
inherited
overrideWithValue(AsyncValue<State> value) Override
Overrides a provider with a value, ejecting the default behaviour. [...]
inherited
select<Selected>(Selected selector(AsyncValue<State> value)) ProviderListenable<Selected>
Partially listen to a provider. [...]
inherited
toString() String
A string representation of this object. [...]
inherited
updateShouldNotify(AsyncValue<State> previousState, AsyncValue<State> newState) bool
Called when a provider is rebuilt. Used for providers to not notify their listeners if the exposed value did not change.
override

Operators

operator ==(Object other) bool
The equality operator. [...]
inherited

Constants

family → const AutoDisposeFutureProviderFamilyBuilder
A group of providers that builds their value from an external parameter. [...]
AutoDisposeFutureProviderFamilyBuilder()