Emitter

Event emitter component.

Installation

$ component install component/emitter

API

Emitter(obj)

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);

Emitter#on(event, fn)

Register an event handler fn.

Emitter#once(event, fn)

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

Emitter#off(event, fn)

• 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.

Emitter#emit(event, ...)

Emit an event with variable option args.

Emitter#listeners(event)

Return an array of callbacks, or an empty array.

Emitter#hasListeners(event)

Check if this emitter has event handlers.