Next.js is a popular framework for building server-side rendered React applications. One of the key features that makes Next.js stand out is its data-fetching methods, particularly getServerSideProps. In this post, we’ll explore how and when to use getServerSideProps to fetch data on every request.

What is getServerSideProps?

getServerSideProps is a function in Next.js that allows you to fetch data on the server for each request. It runs on the server during the rendering process and passes the fetched data as props to the page component.

Let’s look an example:

export async function getServerSideProps(context) {
    const res = await fetch('https://jsonplaceholder.typicode.com/posts');
    const data = await res.json();
  
    return {
        props: {
            posts: data,
        },
    };
}

function BlogPage({ posts }) {
    return (
        <div>
            <h1>Blog Posts</h1>
            <ul>
                {posts.map(post => (
                    <li key={post.id}>{post.title}</li>
                ))}
            </ul>
        </div>
    );
}

export default BlogPage;

So, what the previous code does is:

• The getServerSideProps function makes an API call to fetch a list of blog posts.
• The fetched data is passed to the BlogPage component as props.
• Every time the page is requested, getServerSideProps runs again to ensure the data is up-to-date.

Some of the key benefits are:

• Server-Side Rendering: Unlike getStaticProps (which fetches data at build time), getServerSideProps fetches data on each request, making it ideal for pages that require up-to-the-minute data.

• Context Object: The context parameter provides access to various helpful objects such as req, res, query, and params.

• SEO Benefits: Since data is fetched on the server and pre-rendered, it improves SEO compared to client-side data fetching.

But, when to use getServerSideProps?

• Dynamic Content: If your page needs dynamic content that changes frequently, like user profiles or real-time data.
• Personalized Pages: Use cases where the page content depends on the user, such as dashboards or admin panels.
• SEO Optimization: Pages where search engines need to crawl the rendered HTML with fresh data.

Performance considerations

Although getServerSideProps ensures up-to-date data, it may slow down page load times as it fetches data on every request. Consider using caching strategies or switching to getStaticProps if the data does not change often.

Conclusion

getServerSideProps is a powerful data-fetching tool in Next.js, enabling you to build server-rendered pages with ease. Use it wisely to balance dynamic content needs with performance.