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NODEJS Tutorial
About Lesson

In the dynamic world of Node.js development, creating scalable and maintainable applications is crucial. One powerful feature that can significantly boost your application’s functionality and structure is the use of custom middleware. In this post, we’ll explore the ins and outs of creating and implementing custom middleware in your Node.js projects.

Understanding Middleware in Node.js:

Middleware acts as a bridge between the incoming request and the server’s response. It enables you to execute functions during the request-response cycle, providing a way to perform tasks such as authentication, logging, and error handling. Before diving into creating custom middleware, it’s essential to have a solid understanding of how middleware works in Node.js.

Setting Up Your Node.js Project:

If you haven’t already, make sure to set up a Node.js project and install the necessary dependencies, including Express. Express is a minimal and flexible Node.js web application framework that makes it easy to build robust web applications.

npm init -y
npm install express --save

Creating Your Custom Middleware:

Now that your project is set up, let’s create custom middleware to enhance your application. Custom middleware functions are essentially functions that have access to the request object (req), the response object (res), and the next function in the application’s request-response cycle.

// customMiddleware.js

const customMiddleware = (req, res, next) => {
// Your middleware logic goes here
console.log('Executing custom middleware');
next(); // Don't forget to call next() to pass control to the next middleware in the stack

module.exports = customMiddleware;

Implementing Custom Middleware in Express:

To use your custom middleware in an Express application, you need to import it and use the app.use() method.

// app.js

const express = require('express');
const customMiddleware = require('./customMiddleware');

const app = express();

// Use custom middleware for all routes

// Define your routes and other middleware as needed

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
console.log(`Server is running on port ${PORT}`);

Testing Your Custom Middleware:

Now that you’ve implemented your custom middleware, it’s time to test it. Start your Node.js server, and you should see the log statement from your middleware in the console every time a request is made.