ExpressJS - Overview

ExpressJS is a web application framework that provides you with a simple API to build websites, web apps and back ends. With ExpressJS, you need not worry about low level protocols, processes, etc.

What is Express?

Express provides a minimal interface to build our applications. It provides us the tools that are required to build our app. It is flexible as there are numerous modules available on npm, which can be directly plugged into Express.

Express was developed by TJ Holowaychuk and is maintained by the Node.js foundation and numerous open source contributors.

Why Express?

Unlike its competitors like Rails and Django, which have an opinionated way of building applications, Express has no "best way" to do something. It is very flexible and pluggable.

Features of ExpressJS

Following are the salient features of ExpressJS making it a default choice among web application developers.

• Minimalistic Design− ExpressJS is an unopinionated. ExpressJS framework is highly flexible with a simple, minimalistic design principles. We can quickly setup server, define routes and start handling http requests with very few lines of code.

• Middleware/Routing− ExpressJS provides clear options for Routes with support for all kind of HTTP methods like POST, GET, PUT etc.

• Flexibility− There is no prerequisites or any format to follow in order to use ExpressJS. If we know NodeJS, we can write code as per our preference.

• Templating− ExpressJS supports various templating engines like PUG, Jade or EJS to generate HTML content on the fly.

• Static File Serve− ExpressJS supports static files like images/css/javascript from a folder seemlessly.

• NodeJS Based− Core functionalities of asynchronous programming and event driven programming features of NodeJS can be integrated with ExpressJS easily.

Applications of ExpressJS

Following are the salient features of ExpressJS making it a default choice among web application developers.

• Support RESTful APIs− REST Architecture is very powerful style to enable communication of front-end with backend. ExpressJS supports RESTful APIs by design.

• Support for Real Time Applications− Event Driven Programming helps to create chat, parallel collaborative editing tools etc. ExpressJS integrates with Node and supports Event Driven Programming seemlessly.

• Support for Single Page Applications(SPA)− SPA and RESTFul APIs allows Express Based application to update content dynamically enriching user experience.

ExpressJS vs Django vs Ruby on Rails

Pug

Pug (earlier known as Jade) is a terse language for writing HTML templates. It −

• Produces HTML
• Supports dynamic code
• Supports reusability (DRY)

It is one of the most popular template language used with Express.

MongoDB and Mongoose

MongoDB is an open-source, document database designed for ease of development and scaling. This database is also used to store data.

Mongoose is a client API for node.js which makes it easy to access our database from our Express application.