Next.js Getting Started Guide: The Best Choice for Building Modern Web Applications

Introduction

In today's rapidly evolving front-end development landscape, Next.js is a highly regarded framework that provides developers with powerful tools and flexibility to build high-performance, modern web applications. Whether you are a beginner or a developer looking to introduce Next.js into an existing project, this article will provide you with a comprehensive getting started guide to help you understand the basic concepts and usage of Next.js.

What is Next.js?

Next.js is a framework for React designed to help developers quickly build production-ready applications. It offers many powerful features, such as:

• Server-side Rendering (SSR) and Static Generation (SSG): Supports pre-rendering pages on the server, improving loading speed and SEO performance.
• Routing: Built-in file system routing simplifies the management of pages and API routes.
• API Routes: Easily build APIs within the same project without the need for an additional server.
• Performance Optimization: Automatic code splitting reduces initial loading time.

Installing Next.js

Installing Next.js is very simple; just ensure that Node.js is installed in your development environment. You can quickly create a new project with the following command:

npx create-next-app@latest my-next-app
cd my-next-app
npm run dev

After running the above commands, you will see a new Next.js application started at http://localhost:3000.

Project Structure

Once you create a Next.js application, you will see a default directory structure:

my-next-app/
├── node_modules/
├── public/
├── src/
│   ├── pages/
│   ├── styles/
│   └── components/
├── package.json
└── next.config.js

• pages/: The directory for storing pages; each .js file automatically corresponds to a route.
• public/: The directory for static files; any files placed in this directory can be accessed directly.
• styles/: The directory for storing CSS files, which can be used for global or specific component styles.

Creating Pages and Routes

Next.js manages routing based on the file system. Create a file in the pages/ directory, such as about.js, with the following content:

export default function About() {
  return 

# About Us

;
}

This will automatically create a /about route to access this page.

Static Generation and Server-side Rendering

Next.js supports Static Generation and Server-side Rendering based on data fetching strategies. Let's see how to implement them:

Static Generation

To pre-generate content at build time, you can use getStaticProps. For example:

export async function getStaticProps() {
  const data = await fetch('https://api.example.com/data');
  const json = await data.json();

  return {
    props: {
      data: json,
    },
  };
}

export default function Page({ data }) {
  return {data.title};
}

Server-side Rendering

If you want to fetch data on every request, you can use getServerSideProps:

export async function getServerSideProps() {
  const res = await fetch('https://api.example.com/data');
  const data = await res.json();

  return { props: { data } };
}

export default function Page({ data }) {
  return {data.title};
}

Adding CSS and Styles

Next.js provides various ways to add CSS styles, the simplest way is to create a CSS file in the styles/ directory and import it in the required pages:

import styles from './styles/Home.module.css';

export default function Home() {
  return 

# Welcome to Next.js!

;
}

Additionally, you can use CSS-in-JS libraries like styled-components or Emotion to handle styles.

API Routes

You can create API routes in the pages/api/ directory. For example, create a hello.js file:

export default function handler(req, res) {
  res.status(200).json({ message: 'Hello API' });
}

API routes can handle requests and responses, providing dynamic data processing capabilities for the front end.

Deploying Next.js Applications

The simplest way to deploy is using Vercel, a free hosting platform created by the Next.js development team. Just push your code to GitHub, then connect your GitHub account through Vercel to automatically build and deploy.

Conclusion

Next.js is an ideal framework for building modern web applications, with its powerful features and flexibility allowing developers to focus on building and optimizing applications. Through this introduction, you should now have a basic understanding of how to use Next.js. I hope you can fully utilize the advantages of Next.js in your future projects to build more efficient web applications.

If you have any questions or need further learning resources, please feel free to refer to the official documentation.