dart_event_notifier

Description:

dart event notifier

event_notifier #
This is a very simple Dart package for adding observability to your objects. It
does not have a dependency on Flutter, so can be used in Dart scripts or even
server-side. It's a slight variation on Flutter's
ChangeNotifier,
bloc et cetera.
The gist of it is that our objects will be notifying of meaningful events that
happen inside of them.
Usage #
See the full example in
example/dart_event_notifier_example.dart.
First define the events that can occur in your objects. Sealed classes and enums
are great for this.
sealed class CounterEvent {
const CounterEvent();
}

final class Incremented extends CounterEvent {
const Incremented();
}

final class Decremented extends CounterEvent {
const Decremented();
}
copied to clipboard
Then write your logic. Mix in the EventNotifer and use notify to post
important events that users of your class might want to react to!
class Counter with EventNotifier<CounterEvent> {
var _value = 0;
int get value => _value;

void increment() {
_value++;
notify(Incremented());
}

void decrement() {
_value--;
notify(Decremented());
}
}
copied to clipboard
To receive the events, listen to the events stream. Simple as that.
void main() {
final counter = Counter();

counter.events.listen((event) {
print('Received event: $event; current value: ${counter.value}');
});
}
copied to clipboard