Node.js and Express.js Fundamentals

Overview

• An 8-hour course teaching the fundamentals of Node.js and Express.js to create backend and full stack web apps using JavaScript.
• Created by John Smilga, who has made multiple courses on the freeCodeCamp YouTube channel.
• Hands-on teaching style with a focus on building projects.

Course Structure

1. Introduction to Node.js and Express.js
   • Basics of Node.js and Express.js framework.
   • Building complex REST API with Express.js.
   • MERN application development.
   • Associated technologies: MongoDB, Mongoose.
   • Knowledge solidification through project building and deployment.
2. Understanding Node.js
   • Node.js: Environment to run JavaScript outside the browser.
   • Created in 2009, built on Chrome’s V8 JavaScript engine.
   • Focus on large community and full-stack app development.
   • Course requirements: Familiarity with basic HTML, CSS, and JavaScript, especially ES6, callbacks, promises, and async/await.
3. Course Fundamentals and Development Setup
   • Dev setup overview.
   • Installation of Node.js.
   • Differences between browser JavaScript and Node.js.
4. Modules in Node.js
   • Built-in modules: os, path, fs, http.
   • Synchronous and asynchronous methods.
5. Express.js Framework
   • Setting up an Express server.
   • Using express.json() and express.static() middleware.
   • Handling different HTTP methods: GET, POST, PUT, DELETE.

Key Concepts

What is Node.js?

• Node.js allows JavaScript to be run outside of the browser.
• Node uses the V8 engine from Chrome for JS execution.
• Developers can create backend and full-stack applications with JavaScript.
• Benefits: Large community, unified language for front-end and back-end.

Node.js Installation and Setup

• Install Node.js from nodejs.org.
• Select LTS (Long Term Support) version for production apps.
• Verify the installation via terminal using node -v.

Running Node.js Code

• Create a project folder and an app.js file.
• Spin up a REPL for interactive coding: node command in terminal.
• Create and run a simple Node application: node app.js.
• Understand Node global variables and the module object.

Node.js Modules

• Built-in modules: os, path, fs, http.
  • Example: os module for operating system info, path for file paths, fs for file system operations, http for creating servers.
• Creating custom modules: Use module.exports to define what will be exported from the module.
• Using Require: Import modules into files.
• Promisified Modules: Convert callback-based modules to promise-based for cleaner async code with util.promisify.

HTTP Module

• Create a server using the http module with http.createServer().
• Handle routing and responses: req, res objects.
• Set status codes and headers for responses.

Express.js Introduction

• Simplifies server creation compared to Node’s built-in http module.
• Installation: npm install express.
• Basic setup: const express = require('express'); and const app = express();.
• Middlewares: express.static, express.json, and custom middleware.

Express.js Routing and Middleware

• RESTful API Development: Building routes for GET, POST, PUT, DELETE.
• Static Assets: Serving CSS, JS, and image files via express.static.
• Route parameters and query strings: Handling dynamic routes and filtering data.
• Custom Middleware: Functions that run during request processing, implementing logging or authentication.

Building API with Express.js

• Serve data as JSON responses using res.json().
• Handle route parameters (e.g., /api/products/:id) and query strings.
• Use of middleware for tasks like authentication, request logging, and error handling.

Tools and Utilities

• Nodemon: Automatically restart the server on file changes, use script in package.json for nodemon app.js.
• Postman: REST client for testing API endpoints.

Deployment

• Overview of deploying Node.js applications.
• Setting up production environments.

Summary

• Node.js allows for JavaScript execution outside the browser using the V8 engine.
• Express.js simplifies backend development with middleware, routing, and easy server setup.
• Utilization of built-in and custom Node.js modules enhances functionality.
• API development requires handling HTTP methods correctly using Express.js.
• Tools like Nodemon and Postman streamline development and testing processes.