1. Introduction

In this tutorial, we aim to explore the features of Next.js, a popular open-source React framework developed by Vercel. This tutorial will guide you through understanding and using key features like automatic routing, server-side rendering, static site generation, hot code reloading, automatic code splitting, and built-in CSS support.

By the end of this tutorial, you will have a solid understanding of these key Next.js features and how to use them in your own projects.

Prerequisites: Basic knowledge of JavaScript, React, and Node.js is required. Familiarity with the command line and npm (Node Package Manager) will also be beneficial.

2. Step-by-Step Guide

Automatic Routing

One of the key features of Next.js is its file-system-based router built on the concept of pages.

When a file is added to the pages directory, it's automatically available as a route. For example, creating a file pages/about.js will be accessible at www.your-site.com/about.

Server Side Rendering (SSR)

Next.js allows pages to be rendered on the server-side, which can lead to improved performance and SEO benefits. By default, Next.js pre-renders every page. This means that Next.js generates HTML for each page in advance, instead of having it all done by client-side JavaScript.

Static Site Generation (SSG)

Next.js supports Static Site Generation. With SSG, you can generate the HTML at build time and will be reused on each request. To use it, export an async function called getStaticProps from a page.

Hot Code Reloading

Next.js automatically provides hot code reloading. This means that changes in the code will be immediately reflected in the browser, without a full page refresh.

Automatic Code Splitting

Next.js does code-splitting automatically, so each page only loads what’s necessary. This means faster page loads.

Built-in CSS Support

Next.js allows you to import CSS files from a JavaScript file. This is possible because Next.js extends the concept of import beyond JavaScript.

3. Code Examples

An example of a Next.js page with server-side rendering:

// pages/index.js

function HomePage({ posts }) {
  return (
    <div>
      {posts.map((post) => (
        <div key={post.id}>{post.title}</div>
      ))}
    </div>
  );
}

export async function getServerSideProps(context) {
  const res = await fetch(`https://.../posts`);
  const posts = await res.json();

  return {
    props: {
      posts,
    },
  };
}

export default HomePage;

4. Summary

In this tutorial, we covered key features of Next.js such as automatic routing, server-side rendering, static site generation, hot code reloading, automatic code splitting, and built-in CSS support.

For further learning, consider exploring topics such as API routes, dynamic imports, built-in Sass support, and environment variables in Next.js.

5. Practice Exercises

1. Create a new Next.js application and add three pages (Home, About, Contact) using automatic routing.

2. Fetch data from an API and render it on a page using server-side rendering.

3. For the API data from exercise 2, implement static site generation.

Remember, the best way to learn is by doing. Keep practicing and exploring the extensive features of Next.js. Good luck!