Scaler – Web Development Full Course Module 5: Advanced Backend Development with Node.js and Express.js

Welcome to Module 5 of the Web Development Full Course focused on Advanced Backend Development using Node.js and Expressjs. In this module, we will dive deep into building powerful and scalable backend applications using these technologies.

Node.js is a popular JavaScript runtime built on Chrome’s V8 JavaScript engine. It allows you to run JavaScript on the server-side, giving you the ability to build dynamic web applications. Expressjs is a lightweight and flexible Node.js web application framework that provides a robust set of features for building web applications and APIs.

In this tutorial, you will learn how to set up a Node.js project, create a basic Expressjs server, handle routing, use middleware, work with databases, and deploy your application to a production server.

Setting up a Node.js Project:

1. Start by installing Node.js on your machine. You can download and install Node.js from the official website (https://nodejs.org/).
2. Once Node.js is installed, open a command line interface (CLI) and create a new directory for your project.
3. Navigate into the project directory using the CLI and run the following command to initialize a new Node.js project:
   npm init
4. Follow the prompts to set up your project details, such as the project name, version, description, entry point, etc.

Creating a Basic Expressjs Server:

1. Install Expressjs by running the following command in your project directory:
   npm install express
2. Create a new file (e.g., server.js) in your project directory and add the following code to create a basic Express server:

   
   const express = require('express');
   const app = express();

app.get(‘/’, (req, res) => {
res.send(‘Hello, World!’);
});

app.listen(3000, () => {
console.log(‘Server started on port 3000’);
});

3. Save the file and run the following command in the CLI to start the Express server:
   `node server.js`
4. Open a web browser and navigate to `http://localhost:3000` to see the "Hello, World!" message.

Handling Routing in Expressjs:
1. Expressjs uses a routing mechanism to define different routes and handle HTTP requests. You can define routes using the `app.get()`, `app.post()`, `app.put()`, and `app.delete()` methods.
2. Update the `server.js` file to include multiple routes:

app.get(‘/’, (req, res) => {
res.send(‘Home Page’);
});

app.get(‘/about’, (req, res) => {
res.send(‘About Page’);
});

app.get(‘/contact’, (req, res) => {
res.send(‘Contact Page’);
});

Using Middleware in Expressjs:
1. Middleware functions are functions that have access to the request object (`req`), the response object (`res`), and the next middleware function in the application's request-response cycle.
2. Add middleware functions to your Express application by using the `app.use()` method.
3. Create a middleware function that logs the request method and URL to the console:

app.use((req, res, next) => {
console.log(${req.method} ${req.url});
next();
});

Working with Databases in Expressjs:
1. To work with databases in Expressjs, you can use various database management systems such as MongoDB, MySQL, PostgreSQL, etc.
2. Install a database driver package (e.g., `mongoose` for MongoDB) using npm:
   `npm install mongoose`
3. Connect to your database in the `server.js` file and define database models:

const mongoose = require(‘mongoose’);
mongoose.connect(‘mongodb://localhost/myapp’);

const User = mongoose.model(‘User’, {
name: String,
email: String,
age: Number
});

Deploying Your Application to a Production Server:
1. Before deploying your application to a production server, make sure to optimize your code, secure your application, and configure environment variables for sensitive data.
2. You can deploy your Express application to popular hosting platforms such as Heroku, AWS, DigitalOcean, etc.
3. Follow the hosting provider's documentation to deploy your Node.js application to a production server.

In conclusion, this tutorial provided an overview of advanced backend development using Node.js and Expressjs. By following the steps outlined in this module, you can build powerful and scalable backend applications for your web projects. Remember to practice and experiment with different features of Node.js and Expressjs to enhance your backend development skills. Good luck with your journey into advanced backend development!