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The Ultimate Guide to React Server Components in 2024

Majd Muhtaseb05/25/20258 minutes

Introduction to React Server Components

React Server Components (RSCs) are a revolutionary addition to the React ecosystem, offering a new way to build performant and efficient applications. Unlike traditional client-side components, RSCs execute on the server, reducing the amount of JavaScript sent to the client. This results in faster initial page loads, improved SEO, and a better user experience.

Benefits of Using RSCs

• Improved Performance: Reduced client-side JavaScript leads to faster initial load times.
• Enhanced SEO: Server-side rendering makes it easier for search engines to crawl and index your content.
• Access to Server Resources: RSCs can directly access databases and other server-side resources without the need for an API.
• Simplified Data Fetching: Data fetching logic can be colocated with your components, making your code cleaner and easier to maintain.

Key Concepts

• Server Components: Run only on the server and cannot use client-side interactivity (e.g., useState, useEffect).
• Client Components: Run in the browser and can use client-side interactivity. They need to be explicitly marked with 'use client'.
• Serialization: Data passed from server to client components must be serializable.

Practical Example (Next.js)

This example demonstrates how to fetch data in a Server Component and render it.

// app/page.js (Server Component)

async function getData() {
  const res = await fetch('https://jsonplaceholder.typicode.com/todos/1');
  // The return value is *not* serialized
  // You can return Date, Map, Set, etc.

  if (!res.ok) {
    // This will activate the closest `error.js` Error Boundary
    throw new Error('Failed to fetch data')
  }

  return res.json()
}

export default async function Page() {
  const data = await getData()

  return (
    <div>
      <h1>Todo</h1>
      <p>User ID: {data.userId}</p>
      <p>Title: {data.title}</p>
      <p>Completed: {data.completed ? 'Yes' : 'No'}</p>
    </div>
  )
}

This Page component is a Server Component because it's not marked with 'use client'. It fetches data directly from an API and renders it.

Integrating Client Components

To use Client Components within Server Components, you'll need to import and render them. Remember to mark your Client Component with 'use client'.

// app/components/LikeButton.js (Client Component)

'use client';

import { useState } from 'react';

export default function LikeButton() {
  const [likes, setLikes] = useState(0);

  return (
    <button onClick={() => setLikes(likes + 1)}>
      Likes: {likes}
    </button>
  );
}

// app/page.js (Server Component)

import LikeButton from './components/LikeButton';

export default async function Page() {
  return (
    <div>
      <h1>My Page</h1>
      <LikeButton />
    </div>
  );
}

Conclusion

React Server Components are a powerful tool for building modern, performant React applications. By understanding their benefits and how to use them effectively, you can significantly improve the user experience and overall performance of your applications. Embrace the shift to server-first rendering and unlock the full potential of React in 2024.