ExpressJS Tutorial

Express.js Tutorial

ExpressJS is a web framework built on top of Node.js that enables you to design a web application to handle a variety of different HTTP requests and makes web application creation quick and simple. We will learn about the Express framework in this course.

What is Express.js?

Express.js, usually known as Express is a Node.js backend framework that is straightforward and quick. It offers powerful capabilities and tools for creating scalable backend applications. It provides you with a routing system and simpler functionality to extend the framework by constructing more powerful components and elements based on your application use cases.

The framework offers a collection of tools for developing and delivering massive, enterprise-ready online applications, HTTP requests and replies, routing, and middleware. Additionally, it offers the Node Package Manager (NPM) command-line interface tool (CLI), which enables developers to find developed packages. It also enforces the Don't Repeat Yourself (DRY) philosophy on developers. 

Why use Express

Let us look at the reasons why we should use Express framework :

• Improves scalability of the application : The first benefit of utilizing Express.js for backend development is the simplicity of application scaling.
• Backend and frontend code can both be written in the same language : The ability to code both the front end and the back end using JavaScript is another benefit of using Express.js.
• It requires less development and maintenance cost : Express. JS is a full-stack JavaScript that eliminates the need for several engineers to manage the frontend and backend of a website.
• Managing errors effectively : The middleware of Express is designed to enable error detection in both synchronous and asynchronous code.
• Responding to I/O requests : Express is a fantastic option for companies that daily deal with tens of thousands of customer requests and notifications.
• Unopinionated Framework : Express has no hard-and-fast rules for how to handle particular duties, so you can use middleware components and packages however works best for you.
• Simple Assembly : Express has a short learning curve and is simple to set up and set up because it is a minimalist framework. It is suitable for beginners with a fundamental grasp of backend development because of this feature.

Express JS is widely used in the development community to create a variety of applications. Below, we look at a few of them.

• Accenture
• Yummly
• Uber
• MySpace
• Accuweather

Basic Express.js app

Let us see a simple and basic express app :

Once you have done with installing the express in the project you can make a App.js file with the following code :

// requiring express
var express = require('express'); 

// creating an express app
var app = express();  

app.get('/', function (req, res) {  
  res.send('Welcome to JavaTpoint!');  
});  

const PORT = 3000;
app.listen(PORT, () => {
    console.log(`Server Started at PORT : ${PORT}`)
})

You can see the result by using the command :

node App.js

Output :

[IMAGE 1 output) START SAMPLE]

[IMAGE 1 FINISH SAMPLE]

Advantages of Express.js

Let us look at the advantages of ExpressJS :

• Middleware : Before receiving responses, inbound requests are processed by middleware in ExpressJS. This enables you to carry out operations like validation, authentication, and logging in a modular and reusable way.
• Routing : ExpressJS offers a straightforward and organised approach to manage various HTTP requests and associate them with particular actions.
• Templating : ExpressJS comes with integrated support for a number of well-known templating engines, including EJS and Jade, which facilitates the creation of dynamic and interactive pages.
• Database Integration : The storage and retrieval of data in your web application is made simple by the ease with which ExpressJS can be linked with well-known databases like MongoDB and MySQL.
• Scalable : ExpressJS is excellent for creating large and sophisticated web applications since it is scalable and effective by design.
• Large Community : A sizable and vibrant developer community supports and contributes to the development of ExpressJS.

Audience

The purpose of this tutorial is to introduce software developers to ExpressJS and its foundational concepts. This tutorial will give you a complete understanding of all the required elements of ExpressJS by using the right examples.

Prerequisite

After learning more about Express.js, you ought to have a better understanding of how it could improve your skill set. Now let's look at the requirements for learning Express.js.

• JavaScript - Because the ExpressJS environment was created for writing JavaScript code, we must have a firm grasp of both the basic and more advanced principles of JavaScript. It is necessary to have a fundamental understanding of this keyword, expressions, loops, data structures, callbacks, functions, and other relevant javascript concepts.
• Asynchronous code - Before diving into Express.js, you must be well versed on asynchronous programming and how it works. Asynchronous code or architecture allows for several tasks to be completed at once without interfering with the main thread's execution.
• NPM - The Node Package Manager, sometimes known as "NPM," is a highly useful tool for managing the server-side dependencies of any Expess.js project. Installing, updating, and, if required, removing various JavaScript libraries and packages is made simple using "NPM."
• HTTP - You must send an API request via "HTTP" to the server in order to submit data to the server or get data from a data source. When working on a web project, it would be helpful to have a basic understanding of HTTP methods and HTTP requests such as GET, POST, DELETE, PUT, and PATCH, among others.
• CLI - Command Line Interface, or CLI for short, is a text-based user interface that allows you to enter commands to direct your computer to carry out certain actions.

About this Express Js Tutorial

Key concepts covered in this tutorial will be :

• Query Parameter in Express
• Third party Middleware in ExpressJS
• Builtin MiddleWar in ExpressJS
• express sessions
• Mongoose with express js
• Express cookies
• pug node js express
• express js vs node js
• Sending Response in Express
• Redirect with ExpressJS
• Serving static files in Expressjs
• Express Scaffolding using Express generator
• What is Express and Why use it ?
• Express Router
• Uploading files in expressjs
• Error Handling in ExpressJS
• Getting Started with ExpressJS
• Prerequisites of Express
• Introduction to routing in Expressjs
• CRUD in Express
• Template Route in Express
• Introduction to MiddleWare architecture of ExpressJS .
• Custom middleware in ExpressJS
• Different Response Methods
• MongoDB with express js
• Protect against XSS attacks
• Express cors
• Websockets in expressjs
• Handling form submission
• Integrating express with react
• Creating MVC architecture for restful API
• Debugging and Logging in Express
• Sequelize with express js
• Performing CRUD in MYSQL with Expressjs
• Performing CRUD in mongodb with Expressjs
• Different types of attacks in express
• Protecting against CSRF attacks
• Deploying an Express application
• Monitoring and scaling an express server
• Templating engine for Express
• express js main hub page
• Integrating express with VUE

Take-Away Skills from This Express Js Tutorial

• ExpressJS is a web framework that enables you to design a web application to handle a variety of different HTTP demands.
• Managing queries and parameters inside the URL string is simple with Express.
• Express query params can be easily extracted from the query object, which is on the request object that was submitted to your route.
• Serving static files and routing in the express server.
• Express can quickly and easily add CORS functionality if we utilize the core library.
• Express is easily compatible with MongoDB and other databases in order to store and access data.
• Pug node js express templates make it possible for the server-side data that must be sent to the application to be rendered quickly.
• Sessions enable the HTTP protocol to go from being stateless to stateful and can easily be implemented in an express framework.
• Implementing CRUD functionalities in express.
• Scaffolding which allows us to easily create a skeleton for a web application using express generators.
• Express Cross-Site Scripting happens when dynamically generated web pages show user input that hasn't been properly validated, like login information.