Redux and Server-Side Rendering
Tags: redux, javascript, webdev, beginners
Published: 2024-01-27 08:49:06

**What is Server-Side Rendering?**

Server-side rendering (SSR) is a technique that allows web pages to be rendered on the server before being sent to the client. This means that the server sends a fully rendered HTML page to the client, rather than just a blank HTML file with JavaScript that needs to be executed to render the page. This technique has several benefits, including faster page load times, better search engine optimization, and improved accessibility.

**What is Redux?**

Redux is a state management library for JavaScript applications. It provides a predictable state container that can be used to manage the state of an application in a consistent and reliable way. Redux is often used in conjunction with React, but it can be used with any JavaScript framework or library.

**Why use Redux with Server-Side Rendering?**

When using server-side rendering, it's important to send the initial state of the application along with the HTML response. This is because the client needs to have access to the same state that was used to render the HTML on the server. If the client doesn't have access to the same state, the client-side rendering will not match the server-side rendering, which can lead to issues such as flickering or incorrect data.

Redux is a great choice for managing the state of an application when using server-side rendering. This is because Redux provides a predictable state container that can be used to manage the state of an application in a consistent and reliable way. When using Redux with server-side rendering, the initial state of the application can be sent along with the HTML response, ensuring that the client has access to the same state that was used to render the HTML on the server.

**How to use Redux with Server-Side Rendering**

To use Redux with server-side rendering, we need to create a new Redux store instance on every request, dispatch some actions if necessary, pull the state out of the store, and then pass the state along to the client. On the client side, a new Redux store will be created and initialized with the state provided from the server.

Here's an example of how to set up server-side rendering with Redux:

1. Install the required packages:
```
npm install express react-redux
```

2. Create a new Redux store instance on every request:
```
import { createStore } from 'redux';
import { Provider } from 'react-redux';
import rootReducer from './reducers';

function handleRender(req, res) {
  const store = createStore(rootReducer);

  // Render the component with the current state
  const html = renderToString(
    <Provider store={store}>
      <App />
    </Provider>
  );

  // Send the rendered HTML back to the client
  res.send(renderFullPage(html, store.getState()));
}
```

3. Pass the state along to the client:
```
function renderFullPage(html, preloadedState) {
  return `
    <!doctype html>
    <html>
      <head>
        <title>My App</title>
      </head>
      <body>
        <div id="app">${html}</div>
        <script>
          window.__PRELOADED_STATE__ = ${JSON.stringify(preloadedState).replace(/</g, '\\u003c')}
        </script>
        <script src="/bundle.js"></script>
      </body>
    </html>
  `;
}
```

4. Create a new Redux store on the client side:
```
import { createStore } from 'redux';
import { Provider } from 'react-redux';
import rootReducer from './reducers';

const preloadedState = window.__PRELOADED_STATE__;
const store = createStore(rootReducer, preloadedState);

ReactDOM.render(
  <Provider store={store}>
    <App />
  </Provider>,
  document.getElementById('app')
);
```

**Conclusion**

Server-side rendering is a powerful technique that can improve the performance, accessibility, and search engine optimization of web applications. When using server-side rendering, it's important to send the initial state of the application along with the HTML response. Redux is a great choice for managing the state of an application when using server-side rendering, as it provides a predictable state container that can be used to manage the state of an application in a consistent and reliable way. By following the steps outlined in this guide, you can easily set up server-side rendering with Redux in your own applications.