The Talent500 Blog

Express.js for Javascript Developers

Debaleena Ghosh

Express.js is a popular, lightweight, and minimalist web framework for Node.js. It provides a set of powerful features and tools that simplify the development of server-side web applications.  Express.js is built on top of Node.js and offers a high level of abstraction for creating web servers and APIs. In this blog post, we’ll dive into the technical details of Express.js and explore its key features, advantages, and limitations. We’ll also share step-by-step instructions on how to create a basic web application using Express.js.

But before that, let’s dig through the history of Express.js.

ExpressJS History  

Express.js was first released in 2010. It was created by TJ Holowaychuk, who is also the creator of many other popular Node.js modules, such as Stylus, Jade, and Mocha.

It was created to address some of the limitations of the Node.js core HTTP module. While the HTTP module provided a basic framework for handling HTTP requests and responses, it lacked some of the features needed for building complex web applications and APIs.

Express.js was designed to provide a more comprehensive framework for building web applications and APIs with Node.js. It provided a set of features and tools for handling routing, middleware, request/response handling, and more. With Express.js, developers could build web applications and APIs more quickly and with fewer lines of code.

Over the years, Express.js has become one of the most common web frameworks for Node.js, with a large and active developer community. It has evolved to incorporate new features and tools, such as support for WebSockets, sessions, and cookie parsing.

Key Features:

Advantages:

Limitations:

Use Cases of Express.js:

Express.js provides a set of tools and features for building web applications and APIs. Here are some of the use cases for Express.js:

Popular Apps Using Express.js:

Express.js is used by many companies and organizations to build web applications and APIs. Here are some of the popular apps that are built with Express.js:

   

Comparative analysis between Express.js, Node.js and Angular.JS

Express.js, Node.js, and AngularJS are three popular web technologies that are often used together to build modern web applications. Although they are all used in web development, they are different in their purpose, architecture, and functionality.

  Node.js Express.js AngularJS 

 

 

 
Definition Node.js is an open-source, cross-platform, server-side runtime environment that is built on Chrome’s V8 JavaScript engine. It allows developers to build fast and scalable network applications using JavaScript on the server side. Express.js represents a lightweight and flexible web framework for Node.js that simplifies the development of server-side web applications. It provides a set of powerful features and tools that allow developers to create RESTful APIs and web applications quickly and easily. AngularJS is a popular front-end JavaScript framework for building dynamic and responsive web applications. It provides a powerful set of tools and features that allow developers to build single-page applications (SPAs) with ease.
Features
  • The event-driven architecture enables non-blocking I/O operations, making it fast and scalable.
  • Single-threaded. It can handle a large number of requests simultaneously without using a lot of system resources.
  • Built-in modules for networking, file system I/O, and cryptography, making it easy to build server-side applications.
  • Routing mechanism that allows developers to define endpoints and handle incoming requests with ease.
  • Middleware functions that allow developers to modify and control the flow of incoming requests and outgoing responses.
  • Supports various templating engines such as EJS, Pug, & Handlebars, allowing developers to create dynamic HTML pages.
  • Comprehensive error handling mechanism that allows developers to catch and handle errors in a structured and organised manner.
  • Two-way data binding allows changes in the model to automatically reflect in the view and vice versa.
  • Dependency injection that allows for modular and reusable code.
  • Directives that allow developers to create custom HTML tags and attributes to extend the functionality of HTML.
  • A testing framework allows developers to write tests for their code, ensuring that it works as expected.
Architecture Node.js is a runtime environment for JavaScript  Express.js is a web framework built on top of Node.js.  AngularJS is a front-end JavaScript framework.
Purpose Node.js is used to build server-side applications.  Express.js is used to build RESTful APIs and web applications. AngularJS is used to build front-end applications.
Functionality Node.js provides a set of built-in modules for networking, file system I/O, and cryptography.  Express.js provides a routing mechanism, middleware functions, and an error-handling mechanism.  AngularJS provides tools and features for building dynamic and responsive front-end applications.

 

 
Development Approach Server-side development approach Server-side development approach Client-side development approach
Learning Curve Steeper learning curve

 

 

 Steeper learning curve Relatively easier learning curve due to its declarative and modular nature.

 

 

Benefits of Using Express js With React js

React.js is a front-end library for developing user interfaces, while Express.js is a popular back-end web framework for building web applications and APIs. Using Express.js with React.js can provide several benefits:

Getting Started with Express.js:

Now that we’ve discussed the key features, advantages, and limitations of Express.js, let’s dive into how to create a basic web application using Express.js.

Step 1: Install Node.js and Express.js

Before you can start building an application with Express.js, you need to install Node.js and the Express.js package. You can install Node.js by visiting the official website (https://nodejs.org/) and downloading the appropriate installer for your operating system.

Once Node.js is installed, you can easily install Express.js by executing the following command in your terminal:

npm install express

Step 2: Create a New Project

Once you have installed Node.js and Express.js, you can create a new project by generating a new directory and navigating to it in your terminal. Once you are in the directory, you can execute the following command to develop a new package.json file:

npm init -y

This’ll create a new package.json file with default values.

Step 3: Create a Server

Next, you need to create a server using Express.js. To do this, develop a new file called app.js and add the following code:

const express = require(‘express’);

const app = express();

app.get(‘/’, (req, res) => {

  res.send(‘Hello World!’);

});

app.listen(3000, () => {

  console.log(‘Server listening on port 3000’);

});

This code creates a new Express.js application, defines a route for the root path /, and sets up a listener on port 3000.

Step 4: Run the Server

Finally, you can run the server by executing the following command in your terminal:

node app.js

This will start the server, and you should be able to see the message “Server listening on port 3000” in your terminal.

What Does an ExpressJS Developer Do?

An Express.js developer is responsible for developing and maintaining web applications and APIs using the Express.js framework for Node.js. Here are some of the generic tasks and responsibilities of an Express.js developer:

How to Become an ExpressJS Developer

If you want to become an Express.js developer, the following are some steps you can take:

Learn JavaScript
  • Express.js is built on top of Node.js, which is a JavaScript runtime. Therefore, it’s important to have a solid understanding of JavaScript before diving into Express.js. 
  • You can start by learning the basics of JavaScript syntax, data types, and control structures and then move ahead to more advanced topics such as functions, objects, and asynchronous programming.

Learn Node.js
  • Express.js is a framework for building web applications with Node.js, so it’s vital to have a good understanding of Node.js. 
  • You can start by learning the basics of Node.js, such as how to create and run Node.js applications, how to work with the Node.js core modules, and how to use Node.js to work with the file system and network.

Learn Express.js
  • Once you have a good understanding of JavaScript and Node.js, you can start learning Express.js. 
  • There are many resources available for learning Express.js, including the official Express.js documentation, online tutorials, and courses. 
  • Some key concepts to learn include routing, middleware, request/response handling, and template engines.

Build projects
  • One of the best ways to learn Express.js is to build projects. Start with simple and easy projects and gradually work your way up to more intricate ones. 
  • This will give you hands-on experience with building web applications and APIs using Express.js and help you develop a deeper understanding of the framework.

Learn database integration
  • Many web applications and APIs require data storage and retrieval. Therefore, it’s important to learn how to integrate Express.js with databases such as MongoDB, MySQL, or PostgreSQL.
  • There are many resources available for learning database integration with Express.js.

Practice good coding practices
  • As with any development work, it’s important to practice good coding practices. This includes writing clean, maintainable, and modular code, using version control systems like Git, writing unit tests, and documenting your code.

Stay up-to-date
  • The web development landscape is constantly evolving, and new technologies and frameworks are being developed all the time. 
  • Therefore, it’s important to stay up-to-date with the latest developments in Express.js and related technologies.

ExpressJS Development Best Practices

Here are some Express.js development best practices:

Use middleware 

Middleware functions in Express.js are used to adjust the request and response objects, handle errors, and perform other tasks. Using middleware can help you write clean and modular code, as it separates concerns and allows you to reuse code across different routes. 

Use a router

Routers in Express.js are used to group related routes and middleware functions. Using a router can help you organize your code and make it easier to maintain.

Use environment variables

Express.js applications often have configuration variables that depend on the environment (e.g., development, production). Using environment variables can help you manage these variables and make your code more portable.

Use a logging library.

Logging is an important aspect of web application development, as it helps you debug issues and monitor application performance. Using a logging library can help you write more effective logs and make searching and analysing them easier.

Use a validation library.

Validating input from users is an important aspect of web application development. Using a validation library can help you ensure the received user data is valid and prevent security issues.

Use a templating engine.

Templating engines in Express.js are used to generate HTML pages dynamically. Using a templating engine can help you write clean and maintainable code, as it separates HTML markup from code.

Use a task runner

Task runners like Grunt or Gulp can help you automate repetitive tasks like minification, concatenation, and deployment.

Use error-handling middleware

Error handling middleware can help you handle errors that occur during request processing. Using error-handling middleware can help you write more robust and reliable code.

Use testing frameworks

Testing is an important aspect of web application development, as it helps you catch bugs and ensure that your code works as expected. Using a testing framework like Mocha or Jest can help you write automated tests for your code.

Use security best practices.

Security is an important aspect of web application development. Using security best practices like input validation, parameterized queries, and HTTPS can help you prevent security issues like SQL injection, cross-site scripting, and man-in-the-middle attacks.

Express.js functions Complete Reference.

php

const session = require(‘express-session’);

const app = express();

app.use(session({

  secret: ‘my secret’,

  resave: false,

  saveUninitialized: true,

  cookie: { maxAge: 60000 }

}));

Javascript

const express = require(‘express’);

const router = express.Router();

router.get(‘/’, (req, res) => {

  res.send(‘Hello, World!’);

});

module.exports = router;

php

const express = require(‘express’);

const app = express();

app.use(express.static(‘public’));

php

const express = require(‘express’);

const app = express();

app.use(express.urlencoded({ extended: true }));

php

const express = require(‘express’);

const app = express();

app.use(express.raw());

Wrapping Up

Express.js is a powerful web application framework for Node.js that offers a wide range of features, such as a robust routing system, middleware support, and template engine integration. It’s an easy-to-learn and versatile framework that can be used to build a variety of web applications. 

With an active community of developers and third-party plugins, Express.js is continuously evolving, making it a top choice for web development. 

So, whether you’re a newbie tech enthusiast or an experienced developer, learning Express.js can take your web development skills to an advanced level.

                 

 

 

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