Node.js Events

var events = require('events');
var eventEmitter = new events.EventEmitter();
 
var ringBell = function ringBell()
{
  console.log('ring ring ring');
}
eventEmitter.on('doorOpen', ringBell);
 
eventEmitter.emit('doorOpen');

eventEmitter.on('doorOpen', ringBell);
eventEmitter.on(‘doorOpen’, doSomething);
eventEmitter.on(‘doorOpen’, doSomethingElse);
 
eventEmitter.emit('doorOpen');

eventEmitter.on(‘doorOpen’, function(ring)
{
    Console.log(ring);
}
eventEmitter.emit(‘doorOpen’, ‘ringeling’);

var events = require('events');
 
function Door(colour) {
  this.colour = colour;
  events.EventEmitter.call(this);
 
  this.open = function()
  {
  this.emit('open');
  }
}
 
Door.prototype.__proto__ = events.EventEmitter.prototype;
 
var frontDoor = new Door('brown');
 
frontDoor.on('open', function() {
    console.log('ring ring ring');
  });
frontDoor.open();

var ring = function()
{
    console.log('ring');
}
frontDoor.on('open', ring);
 
console.log(require('util').inspect(frontDoor.listeners('open'))); // Outputs ring

frontDoor.removeListener('open', ring);

frontDoor.removeAllListeners(‘open’);

• Node.js Events and EventEmitter