EventEmitter in Node

emitter.js

var EventEmitter = require('events').EventEmitter;
var util = require('util');

function Player(name, signature){
  this.name = name;
  this.signature = signature;
}

util.inherits(Player, EventEmitter);

Player.prototype.run = function() {
  var self = this;
  setTimeout(function() {
    self.emit('score', self.signature);
  }, 5000);
};

// Running code

var player = new Player('Messi', 'kick');
player.on('score', function(style) {
  console.log('Player: ' + player.name + ' scored via: ' + style);
});
player.run();

var player2 = new Player('Puyol', 'header');
player2.on('score', function(style) {
  console.log('Player: ' + player2.name + ' scored via: ' + style);
});
player2.run();