watch<T extends Object?> method
Gets the instance of T
type from the closest ancestor ReactterProvider
and listens changes to the instance or the states(ReactterState) defined
in first parameter(listenStates
) to trigger rebuild of the Widget tree.
final appController = context.watch<AppController>();
final appControllerWatchStates = context.watch<AppController>(
(inst) => [inst.stateA],
);
final appControllerNullable = context.wath<AppController?>();
If T
is nullable and no matching instance is found,
watch will return null
.
If T
is non-nullable and the instance obtained returned null
,
will throw ProviderNullException
.
This method is equivalent to calling:
ReactterProvider.contextOf<T>(context, listenStates: listenStates);
Implementation
T watch<T extends Object?>([ListenStates<T>? listenStates]) {
return ReactterProvider.contextOf<T>(this, listenStates: listenStates);
}