An example of an event emitter class in Node.js

node-event-emitter.js

var events = require('events'),
	util = require('util');

EventGenerator = function() {
	events.EventEmitter.call(this);

	this.read = function() {
		var data = "this is new data";
		this.emit("data", data);
	}
}
util.inherits(EventGenerator, events.EventEmitter);

function setup() {
	return(new EventGenerator());
}

var generator = setup();

generator.on("data", function(data) {
	console.log("new data received: " + data);
})

generator.read();