Guide to Setting Up Server-Side Rendering (SSR) with Next.js and Styled Components

1. Overview of Server-Side Rendering (SSR)

SSR is a method where the server renders HTML when the client requests a web page. This contrasts with Client-Side Rendering (CSR), where all rendering tasks are performed on the client side. The main benefits of SSR are:

• Faster initial loading time: By providing server-rendered HTML, the browser can display the page quickly.
• Improved SEO: Search engine crawlers can easily index the complete HTML, enhancing SEO performance.

2. Introduction to Styled Components

Styled Components is a library that allows you to write CSS directly within JavaScript code. This enables you to manage styles and components in the same file and prevents styling conflicts. Styled Components particularly complement component-based libraries like React.

3. Setting Up SSR with Styled Components in Next.js

Next.js is a React-based framework that natively supports server-side rendering. When used with Styled Components, it can render HTML with styles on the server and deliver it to the client. To achieve this, you need to customize Next.js’s `Document` class and use the `ServerStyleSheet` from Styled Components.

4. Code Example

Here is an example of setting up SSR with Styled Components in a Next.js application:

Setting up _document.js file

import Document from 'next/document';
import { ServerStyleSheet } from 'styled-components';

class MyDocument extends Document {
  static async getInitialProps(ctx) {
    // Create an instance of ServerStyleSheet
    const sheet = new ServerStyleSheet();
    const originalRenderPage = ctx.renderPage;

    try {
      // Override renderPage to collect styles
      ctx.renderPage = () =>
        originalRenderPage({
          enhanceApp: (App) => (props) =>
            sheet.collectStyles(<App {...props} />),
        });

      // Collect initial props
      const initialProps = await Document.getInitialProps(ctx);

      return {
        ...initialProps,
        styles: (
          <>
            {initialProps.styles}
            {sheet.getStyleElement()}
          </>
        ),
      };
    } finally {
      sheet.seal();
    }
  }
}

export default MyDocument;

Setting up App.js file

import React from 'react';
import styled from 'styled-components';

const Title = styled.h1`
  color: palevioletred;
  font-size: 24px;
`;

const App = () => (
  <div>
    <Title>Hello, Styled Components with SSR!</Title>
  </div>
);

export default App;