Notifier<State> class abstract

A class which exposes a state that can change over time.

For example, Notifier can be used to implement a counter by doing:

final counterPod = notifierPod<Counter, int>(Counter.new);

class Counter extends Notifier<int> {
  @override
  int build() {
    // Inside "build", we return the initial state of the counter.
    return 0;
  }

  void increment() {
    state++;
  }
}

We can then listen to the counter inside widgets by doing:

Text('count: ${context.watch(counterPod)}')

And finally, we can update the counter by doing:

ElevatedButton(
  onTap: () => context.read(counterPod.notifier).increment(),
  child: const Text('increment'),
)

The state of Notifier is expected to be initialized synchronously. For asynchronous initializations, see AsyncNotifier.

Inheritance

• Object
• NotifierBase
• Notifier

Constructors

Notifier()

Properties

hashCode → int

The hash code for this object.

no setter, inherited

ref → Ref

The Ref from the pod associated with this notifier.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

state ↔ State

The current "state" of this Notifier.

getter/setter pair

Methods

addListener(ListenerCallback<State> listener) → RemoveListener

Subscribes to this object.

build() → State

Initialize a Notifier.

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited