on-object

on-object

Register many EventEmitter listeners at once using objects

Usage

npm install on-object

var EventEmitter = require('on-object')
var emitter = new EventEmitter()

emitter.on({
  foo: function () {
    console.log('foo event emitted')
  },
  bar: function () {
    console.log('bar event emitted')
  }
})
emitter.once({ ... })
emitter.removeListener({ ... })

Instantiation

You can just use this module as a replacement for the EventEmitter class in the events module:

var EventEmitter = require('on-object')
var emitter = new EventEmitter()

You can also use it to wrap the methods of a pre-existing EventEmitter:

var EventEmitter = require('events')
var onObject = require('on-object')

var emitter = onObject(new EventEmitter())

Rationale

This module is useful when you find yourself registering many event listeners at once and want the syntax to look a little less noisy.

For example, you might write something like this using the original API:

emitter.on('foo', function () {
  console.log('foo')
})
emitter.on('bar', function () {
  console.log('bar')
})
emitter.on('bar2', function () {
  console.log('bar2')
})

This module will let you do this:

emitter.on({
  foo: function () {
    console.log('bar')
  },
  bar: function () {
    console.log('bar')
  },
  bar2: function () {
    console.log('bar2')
  }
})

Also, you can make it look especially nice with the ES6 object method syntax:

emitter.on({
  foo () {
    console.log('bar')
  },
  bar () {
    console.log('bar')
  },
  bar2 () {
    console.log('bar2')
  }
})