Event emitter component.

$ component install component/emitter

The Emitter may also be used as a mixin. For example a "plain" object may become an emitter, or you may extend an existing prototype.

As an Emitter instance:

var Emitter = require('emitter');
var emitter = new Emitter;
emitter.emit('something');

As a mixin:

var Emitter = require('emitter');
var user = { name: 'tobi' };
Emitter(user);

user.emit('im a user');

As a prototype mixin:

var Emitter = require('emitter');
Emitter(User.prototype);

Register an event handler fn.

Register a single-shot event handler fn, removed immediately after it is invoked the first time.

• Pass event and fn to remove a listener.
• Pass event to remove all listeners on that event.
• Pass nothing to remove all listeners on all events.

Emit an event with variable option args.

Return an array of callbacks, or an empty array.

Check if this emitter has event handlers.

MIT