This is a simple library for implementing event subscription APIs. This project is inspired by event-kit.
import 'package:event_kit/event_kit.dart';
class User {
final Emitter<String> _emitter = new Emitter<String>();
String _name = '';
Disposable onDidChangeName(void handler(String name)) =>
_emitter.on('did-change-name', handler);
void set name(String name) {
if (_name != name) {
_name = name;
_emitter.emit('did-change-name', [name]);
}
}
}In the example above, we implement onDidChangeName on the user object, which
will register callbacks to be invoked whenever the user's name changes. To do
so, we make use of an internal Emitter instance. We use on to subscribe
the given callback in onDidChangeName, and emit in setName to notify
subscribers. Finally, when the User instance is destroyed we call dispose
on the emitter to unsubscribe all subscribers.
Emitter.on returns a Disposable instance, which has a dispose method.
To unsubscribe, simply call dispose on the returned object.
import 'package:event_kit/event_kit.dart';
var subscription = user.onDidChangeName((name) => print('My name is ${name}'));
// Later, to unsubscribe...
subscription.dispose();You can also use CompositeDisposable to combine disposable instances together.
import 'package:event_kit/event_kit.dart';
var subscriptions = new CompositeDisposable();
subscriptions.add(user1.onDidChangeName((name) => print('User 1: ${name}')));
subscriptions.add(user2.onDidChangeName((name) => print('User 2: ${name}')));
// Later, to unsubscribe from *both*...
subscriptions.dispose();Please file feature requests and bugs at the issue tracker.
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