An in-depth look at the Next.js data fetching methods

Introduction

Next.js is a popular React framework that simplifies building server-side rendered (SSR) web applications. One of the key features of Next.js is its data fetching methods, which help developers fetch data from various sources and render it on the client or server side. In this blog post, we'll take an in-depth look at the different data fetching methods offered by Next.js and how to use them to build powerful web applications.

Static Generation (getStaticProps)

Static Generation is the most common data fetching method used in Next.js. It allows developers to pre-render pages at build time and serve them as static HTML files to improve performance and SEO. The getStaticProps method is used to fetch data during build time and pass it as props to the page component. This method can be used to fetch data from various sources such as APIs, databases, and markdown files.

export async function getStaticProps() {
  // Fetch data from an API
  const res = await fetch('<https://example.com/data>')
  const data = await res.json()

  // Pass data as props to the page component
  return {
    props: {
      data
    }
  }
}

Server-side Rendering (getServerSideProps)

Server-side rendering is another data fetching method offered by Next.js. It allows developers to fetch data at the requested time and render pages on the server side. This method is useful for pages that require dynamic data or user authentication. The getServerSideProps method is used to fetch data at the requested time and pass it as props to the page component.

export async function getServerSideProps(context) {
  // Fetch data from an API
  const res = await fetch('<https://example.com/data>')
  const data = await res.json()

  // Pass data as props to the page component
  return {
    props: {
      data
    }
  }
}

Client-side Rendering (useSWR)

Client-side rendering is a data fetching method used to fetch data on the client side. This method is useful for pages that require real-time data updates or user interactions. The useSWR hook is a popular data-fetching library used in Next.js. It allows developers to fetch data from APIs and cache it locally to improve performance.

import useSWR from 'swr'

function MyComponent() {
  const { data, error } = useSWR('<https://example.com/data>', fetcher)

  if (error) return <div>Error...</div>
  if (!data) return <div>Loading...</div>

  // Render data
  return <div>{data}</div>
}

Conclusion

In conclusion, Next.js offers various data fetching methods that can be used to fetch data from various sources and render it on the client or server side. Static Generation is the most common method used to pre-render pages at build time, while Server-side rendering is useful for pages that require dynamic data or user authentication. Client-side rendering is useful for pages that require real-time data updates or user interactions. By understanding these methods, developers can build powerful web applications with Next.js.