NodeJS EventEmitter:

An action performed is termed as an event. Node.js is faster than other frameworks as it uses event driven programming technique. An event is more or less similar as a callback, the only difference is that the event handling works on the observer pattern while, the callback functions are called when an asynchronous function returns its result.

Node.js Events Module:

Events is a built-in module in Node.js which is used to create-, fire-, and listen an event.

Node.js EventEmitter Object:

The Node.js EventEmitter objects are used to assign event handlers to an event in two ways:

Return EventEmitter from a function
Extend the EventEmitter class

Syntax:

To include the Events module:

var events = require(events);

To bind event and event listener:

var eventEmitter = new events.EventEmitter();

To bind event handler with an event:

eventEmitter.on (event_Name, eventHandler);

To fire an event:

eventEmitter.emit (event_Name);

Example:

var events = require(‘events’);

var eventEmitter = new events.EventEmitter();

var Handle = function ()

{

console.log(‘I love Programming!’);

}

eventEmitter.on(‘coders’, Handle);

eventEmitter.emit(‘coders’);

OUTPUT:

I love Programming!

Tags: NodeJS EventEmitter, NodeJS Tutorial