Another JS Event Dispatcher

... just what the internet needs.

Opting In

You can add event dispatchers to objects manually:

foo.events = new EventDispatcher();
foo.events.on('event', handler, foo);

The Observable method will add .__events to the object it's given, and bind the on/once/trigger methods as a courtesy, so that you can ...

function Foo() {
  Observable(this);
  this.on('event', this.handler, this);
}

Binding and Triggering Events

You can either use .on or .once to bind an event. .on will fire in perpetuity; .once will fire only once.

As a convenience, you can pass a Context as the third param, and we'll do the proxy-apply for you.

Event names may be namespaced, jQuery style: Triggering 'action' will fire handlers for 'action' as well as 'action.namespace', while triggering 'action.namespace' will fire handlers for 'action.namespace' but not 'action'.