Implementing Server-Side Rendering in Next.js with TypeScript

Next.js has emerged as one of the leading frameworks for building React applications, thanks to its powerful features like server-side rendering (SSR). Leveraging SSR can significantly enhance your application's performance and SEO. In this article, we’ll explore how to implement server-side rendering in Next.js using TypeScript, offering detailed examples and actionable insights along the way.

What is Server-Side Rendering (SSR)?

Server-side rendering (SSR) is the process of rendering web pages on the server instead of in the browser. When a user requests a page, the server generates the HTML content and sends it to the client. This leads to:

• Faster initial load times: Users receive fully rendered pages more quickly.
• Improved SEO: Search engines can easily crawl and index server-rendered pages.
• Better performance on low-powered devices: Heavy lifting is done on the server, reducing the workload on the client-side.

Why Use Next.js for SSR?

Next.js simplifies the implementation of SSR with built-in support, making it an ideal choice for developers. It provides:

• An intuitive file-system-based routing mechanism.
• Automatic code splitting and optimization.
• Easy integration of TypeScript for type safety.

Setting Up Your Next.js Project

Before diving into server-side rendering, let’s set up a Next.js project with TypeScript.

Step 1: Create a New Next.js App

Open your terminal and run the following command:

npx create-next-app@latest my-next-app --typescript

This command creates a new Next.js application named my-next-app with TypeScript support.

Step 2: Change Directory

Navigate into your project folder:

cd my-next-app

Step 3: Install Dependencies

Although the basic setup is ready, you may want to install additional packages like Axios for data fetching:

npm install axios

Implementing Server-Side Rendering

Now that we have our Next.js project ready, let's implement server-side rendering.

Step 1: Create a New Page

In the pages directory, create a new file named posts.tsx:

// pages/posts.tsx
import { GetServerSideProps } from 'next';
import axios from 'axios';

interface Post {
  id: number;
  title: string;
  body: string;
}

interface Props {
  posts: Post[];
}

const Posts: React.FC<Props> = ({ posts }) => {
  return (
    <div>
      <h1>List of Posts</h1>
      <ul>
        {posts.map((post) => (
          <li key={post.id}>
            <h2>{post.title}</h2>
            <p>{post.body}</p>
          </li>
        ))}
      </ul>
    </div>
  );
};

// Fetch data on server-side
export const getServerSideProps: GetServerSideProps = async () => {
  const res = await axios.get('https://jsonplaceholder.typicode.com/posts');
  const posts = res.data;

  return {
    props: { posts }, // Will be passed to the page component as props
  };
};

export default Posts;

Step 2: Understanding the Code

• GetServerSideProps: This is a special function that fetches data on each request. It runs exclusively on the server and allows us to fetch data before rendering the page.
• Axios: We use Axios to fetch data from an API, in this case, a placeholder API that returns posts.

Step 3: Running the Application

Start your Next.js application:

npm run dev

Visit http://localhost:3000/posts in your browser. You should see a list of posts rendered server-side.

Benefits of SSR with Next.js and TypeScript

1. Type Safety: Using TypeScript ensures that your data structures are well-defined, minimizing runtime errors.
2. SEO Optimization: Server-rendered pages are fully accessible to search engine crawlers, enhancing the visibility of your content.
3. Improved User Experience: Users receive fully rendered pages instantly, leading to lower bounce rates.

Troubleshooting Common Issues

As you implement SSR with Next.js, you may encounter a few common issues:

Issue 1: Data Fetching Errors

If you’re unable to fetch data, ensure that:

• The API URL is correct.
• You handle errors within getServerSideProps:

export const getServerSideProps: GetServerSideProps = async () => {
  try {
    const res = await axios.get('https://jsonplaceholder.typicode.com/posts');
    const posts = res.data;

    return {
      props: { posts },
    };
  } catch (error) {
    console.error(error);
    return {
      props: { posts: [] }, // Return an empty array on error
    };
  }
};

Issue 2: TypeScript Errors

Ensure that your interfaces are correctly defined. If you are unsure about the data shape, use TypeScript's optional properties or union types to accommodate different data structures.

Conclusion

Implementing server-side rendering in Next.js with TypeScript is a straightforward yet powerful way to enhance your web application's performance and SEO. With the steps outlined in this article, you can efficiently set up SSR, fetch data, and render dynamic content. As you build more complex applications, consider exploring additional Next.js features like static site generation (SSG) and API routes to fully leverage the framework’s capabilities. Happy coding!