eventEmitter.js

//first.js
var util = require('util'),
  EventEmitter = require('events');


function First () {
  EventEmitter.call(this)
}
util.inherits(First, EventEmitter);


First.prototype.sendMessage = function (msg) {    
  this.emit('message', {msg:msg});
};


module.exports = First;


// second.js :
var First = require('./first.js');
var firstEvents = new First();

// listen for the 'message event from first.js'
firstEvents.on('message',function(data){
	console.log('recieved data from first.js is : ',data);
});


// to emit message from inside first.js
firstEvents.sendMessage('first message from first.js');