Express.js for Javascript Developers

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:

• Routing: Express.js provides a flexible and powerful routing mechanism that allows developers to define endpoints and handle incoming requests with ease. It supports a variety of HTTP methods, such as GET, POST, PUT, DELETE, and more.

• Middleware: Express.js middleware allows developers to modify and control the flow of incoming requests and outgoing responses. Middleware functions are executed sequentially, allowing developers to perform tasks such as authentication, logging, and error handling.

• Templating: Express.js supports a variety of templating engines, such as EJS, Pug, and Handlebars, which allow developers to create dynamic HTML pages and serve them to clients.

• Error Handling: Express.js provides a comprehensive error-handling mechanism that allows developers to catch and handle errors in a structured and organised manner. It supports both synchronous and asynchronous error handling.

• Extensibility: Express.js is highly extensible and can be seamlessly customized to fit the requirements of any project. It supports a wide range of third-party plugins and modules, making it easy to add new functionality and features to your application.

Advantages:

• Lightweight and Fast: Express.js is built on top of Node.js, known for its speed and performance. Express.js inherit these qualities and provide a lightweight and fast web framework that can handle a high volume of traffic with ease.

• Easy to Learn: Express.js has a simple and intuitive API that makes it easy for developers to get started. The documentation is comprehensive and well-organized, making it easy to understand and implement.

• Flexibility: Express.js is a flexible web framework that can be used to build a variety of applications, from small projects to large-scale enterprise applications. It supports various plugins and modules, making it easy to add new functionality and features as needed.

• Great Community Support: Express.js has a thriving developer support community that contributes to the framework’s development, shares their experiences and knowledge, and supports other developers. community 

Limitations:

• Learning Curve: Although Express.js is relatively easy to learn, it still requires developers to have a good understanding of Node.js and web development concepts. This can be challenging for developers who are new to Node.js or web development.

• Limited Functionality: Express.js is a minimalist framework that provides only basic functionality. Developers may need to add additional modules or plugins to support advanced features such as caching, database integration, and session management.

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:

• Building APIs: Express.js makes it easy to build RESTful APIs by providing a simple and intuitive routing mechanism, middleware, and request/response handling.

• Building web servers: Express.js is lightweight and fast, making it a popular choice for building scalable web servers. It provides a set of features for handling HTTP requests and responses, serving static files, and rendering templates.

• Building real-time applications: Express.js can be used with other technologies, such as Socket.io or WebSockets, to build real-time applications that require bi-directional communication between the client and the server.

• Building microservices: Express.js can be used to build microservices that are part of a larger application architecture. Microservices built with Express.js can be deployed independently and communicate with other microservices using RESTful APIs.

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:

• Trello: A popular project management tool built with Node.js and uses Express.js for its web server.

• Uber: A transportation network company that uses Express.js for its APIs and web server.

• PayPal: An online payment system that uses Express.js for its APIs and the web server.

• LinkedIn: A professional social network that uses Express.js for its APIs and web server.

• Medium: A popular blogging platform that uses Express.js for its web server.

• Netflix: Netflix is a streaming media service that uses Express.js for its APIs and web server.

• MyFitnessPal: A popular fitness app that uses Express.js for its APIs and the web server.

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.

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:

• Scalability: Express.js provides a lightweight and fast web framework that can handle a large number of requests simultaneously. Combined with React.js, you can build scalable web applications that handle heavy traffic and large data sets.
• Routing: Express.js provides a simple and intuitive routing mechanism that can be used to handle incoming requests and responses. By using Express.js with React.js, you can easily define routes and handle requests for different pages and components of your application.
• Middleware: Express.js provides a middleware mechanism that can be used to incorporate additional functionality to your web application, such as authentication, logging, and error handling. By using Express.js with React.js, you can easily integrate middleware into your application and provide additional functionality to your users.
• API Integration: Express.js is designed to work well with APIs and can be used to develop RESTful APIs that can be utilized by front-end applications such as React.js. By using Express.js with React.js, you can easily integrate your front-end application with your back-end API.
• Database Integration: Express.js provides a set of tools and libraries that can be used to integrate with different databases, such as MongoDB, MySQL, and PostgreSQL. By using Express.js with React.js, you can easily integrate your front-end application with your back-end database and provide real-time data updates to your users.

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:

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:

• Developing and maintaining website applications and APIs using the Express.js framework for Node.js.
• Creating and managing routes for different pages and components of the application.
• Implementing middleware for handling requests and responses, such as authentication, logging, and error handling.
• Integrating with databases, such as MongoDB, MySQL, and PostgreSQL, to provide data storage and retrieval.
• Implementing real-time communication using WebSockets or other technologies.
• Optimising application performance and scalability.
• Working with front-end developers to integrate the back-end with the front-end components of the application.
• Writing unit tests and integration tests to ensure code quality and reliability.
• Troubleshooting and debugging issues arising in the application.
• Staying up-to-date with the latest developments in Express.js and related technologies.

How to Become an ExpressJS Developer

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

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.

• express(): The ‘express()‘ function is used to create a new instance of the Express.js application. It returns an object that represents the Express.js application and can be used to configure routes and middleware.

• express.json(): The ‘express.json()’ function is a middleware function that parses incoming JSON requests. It adds a ‘body’ property to the request object containing the parsed JSON data.
• How to expire a session after 1 min of inactivity in the express session of Express.js? You can set the ‘cookie. manage the property of the session to a value that represents the duration of the session in milliseconds. To expire the session after 1 minute of inactivity, you can set ‘cookie.maxAge’ to ‘60000′ (60 seconds x 1000 milliseconds).

• express.Router(): The express. The router () function is used to generate a new router object. Routers can be used to group related routes and middleware functions.

• express.static(): The ‘express.static()’ function is used to serve static files such as images, CSS, and JavaScript files. It considers a directory path as an argument and returns a middleware function that serves files from that directory.

• express.text(): The ‘express.text()’ function is a middleware function that parses incoming plain text requests. It adds a ‘body’ property to the request object containing the parsed text data.
• express.urlencoded(): The ‘express.urlencoded()’ function is a middleware function that parses incoming form-data requests. It adds a body property to the request object containing the parsed form data.

•  express.raw(): The express.raw() function is a middleware function that parses incoming raw binary data requests. It adds a body property to the request object containing the raw data.

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.