Node.js Framework Comparison

Express.js, Koa.js and Hapi.js are the most popular Node.js application frameworks of today and all of them have obvious similarities. Node.js frameworks enable web developers to create a server with few lines of code and creating REST API has become very simple.

Express.js

Express.js is undoubtedly the most popular Node.js application framework in contemporary web development world. Popular frameworks like Sails.js are built based on Express.js and it was described as a “fast and small server side Javascript web development framework built on node.js and V8 Javascript engine” in a web development journal. The current version of Express.js is 4.x

Express.js gained prominence as a web application framework for building single page and multi-page web apps. The finest attraction of Express.js is that many of its features are available as plug-ins and it is the backend component of MEAN stack(MongoDB ExpressJS AngularJS NodeJS). Douglas Christopher and Wilson are the developers of Express.js and it is a cross platform operating system.

Express.js can be downloaded using NPM and the command ‘npm install-g express’ in the node CLI for installing Express.JS. The quickest and easiest way to create express application architecture is to install express generator. Setting for Express applications can be obtained using the app.set and app.get methods. Application level, router level, third party and cookie middleware are available in Express.js web framework. Biggest contribution of Express.js is that it gave backend functionality that allows developers to build software with script on the server side. They can develop server side applications with Node.js and publish those ap plications as websites using Express.js.

var express = require(‘express’);
var app = express();

app.get(‘/’, function (req, res) {
res.send(‘Hello World!’);
});

var server = app.listen(3000, function () {
var host = server.address().address;
var port = server.address().port;

console.log(‘Example app listening at http://%s:%s’, host, port);
});

” The app starts a server and listens on port 3000 for connection. It will respond with “Hello World!” for requests to the root URL (/) or route. ”

KoA.JS

Koa.js is termed as the next generation web application framework for the one and only Node.js. Objective of Koa development team was to build a smaller, expressive and robust foundation for web applications. Koa application is an object containing a wide array of middleware generator functions and they are composed in a stack like manner. Koa is almost similar to other middleware systems like Ruby’s Rack, Connect and so on. Content negotiation, cache freshness and proxy support are the spectacular features provided by Koa.js. It allows performing actions downstream, filter and then manipulating the response upstream. Methods common to all HTTP servers can be integrated directly into Koa’s small 550 SLOC database. This includes numerous functionalities like content negotiation, nominalization of node inconsistencies and redirection. Koa.js is not bundled with any middleware and it is supported in all versions of iojs without any flags. Web developers all over the world were super excited after the initial release of Koa.js and the curious fact is that Koa.js was developed by the same team who developed Express.js.

Koa is known for heavily leveraging Javascript generators provided by Harmony and Javascript generators refer to an experimental technology.

A simple hello world program in Koa.js is illustrated below.

1: var koi = require (‘koi’);
2: var app = koi ();
3:
4: app. use (function *() {
5: this. Body = ‘Hello World';
6 :});
7:
8: app. listen (3000);

We should be running node 0.11.9 or higher along with harmony flag for Javascript generator support. Koa is an innovative and pragmatic Node.js framework which can be used for building complex web applications.

HAPI.JS

Being known as a rich framework for building web applications, Hapi.js enables developers to focus on writing reusable application logic. Hapi is currently used by global corporate giants including PayPal, Walmart, Yahoo as well as Mozilla. As a web application framework, Hapi.js enables granular control over incoming requests. Hapi plug-ins can be broken into small applications with separate business logic very easily and servers should provide only configuration. In tech world, Hapi is being recognized as a battle tested framework for Node.js made by Walmart.

Hapi features huge amount of well maintained official plug-ins including OAuth. Configuration over convention approach of Hapi.js has become a hot topic of discussion among web development experts who are more inclined to convention-overconfiguration approach. Official version is that configuration based approach made the implementation of requirement theme very easy. Hapi.js will be an ideal tool for web developers who are keen on high availability, easy testing as well as easy theming.

var Hapi = require(‘hapi’);

var server = new Hapi.Server();
server.connection({ port: 3000 });

server.route({
method: ‘GET’,
path: ‘/’,
handler: function (request, reply) {
reply(‘Hello, world!’);
}
});
server.start(function () {
console.log(‘Server running at:’, server.info.uri);
});

Save the above as server.js and start the server with the command node server.js. Now, if you visit http://localhost:3000 in your browser, you’ll see the text Hello, world!.