02GEEK: Server Side Rendering

Server Side Rendering

Adding ES6 and JSX Support on the Server

In this tutorial, we expand our Express server's capabilities by integrating Babel Register to enable ES6 and JSX support. This step is crucial for preparing your server to dynamically render React components.

Step 1: Dynamically Pass Variables to EJS Templates

Update your EJS template:
- Replace static HTML with dynamic placeholders.
- Example for a layout template:
```
<html>
  <head>
    <title><%= title %></title>
  </head>
  <body>
    <%= body %>
  </body>
</html>
```
- The <%= %> syntax dynamically injects values into the template.

Update your Express server to pass variables:

app.get('/', (req, res) => {
  res.render('layout/blank', { 
    title: 'Mastering React Performance', 
    body: 'I got a body.' 
  });
});

This sends the title and body properties to the template.

Restart your server to reflect changes:
- Use Ctrl+C to stop the server, then node server.js to restart.

Step 2: Set Up Babel Register

Install Babel Register:
```
npm install @babel/register --save
```
- This package dynamically transpiles ES6+ and JSX files during runtime.
Add Babel Register to your project:
- Place this at the top of your server.js file:
```
require('@babel/register')({
  presets: ['@babel/preset-env', '@babel/preset-react']
});
```
- This ensures all JavaScript files loaded by the server are transpiled to a compatible format.
Configure Babel in your project:
- Create a .babelrc file in your project root:
```
{
  "presets": ["@babel/preset-env", "@babel/preset-react"]
}
```

Step 3: Load React Components Dynamically

Load React and ReactDOMServer:

const React = require('react');
const ReactDOMServer = require('react-dom/server');

Dynamically render React components:

Import your main React app:

const App = require('./path-to-your-app').default;

Render the React component into HTML:

const renderedHTML = ReactDOMServer.renderToString(<App />);

Why Use Babel Register?

Babel Register eliminates the need to precompile files, allowing you to:

Work with ES6 and JSX seamlessly.
Automatically cache transpiled files for optimized performance.
Enable runtime support for modern JavaScript features.

In the next lecture, we’ll combine these tools to render React components directly from the server, completing our journey to isomorphic JavaScript!

2024

The approach described is still functional in 2024, but it is no longer the most efficient or commonly recommended practice. The JavaScript ecosystem has evolved significantly, with modern frameworks and tools providing more streamlined and optimized solutions for server-side rendering (SSR). Here are some key points:

Key Considerations in 2024

1. Babel Register vs. Precompilation

Babel Register is still a valid solution, especially for quick setups. However, it adds runtime overhead as files are transpiled on-the-fly. In a production environment, precompiling your code using a build tool like Webpack or Vite is the preferred approach.
Modern build tools can bundle, minify, and tree-shake your code, resulting in significantly better performance.

2. The Rise of Next.js

Next.js has become the industry standard for server-side rendering and full-stack React applications. It provides:
- Built-in ES6+ and JSX support.
- Automatic code splitting for optimized loading.
- API routes and server-side functions for seamless backend integration.
- File-based routing for simplicity.
- Edge rendering for ultra-low-latency applications.
In 2024, using Next.js eliminates the need for manual Babel configurations or custom Express server setups, significantly reducing complexity.

3. Native ES Modules in Node.js

Node.js has robust ES module support, allowing developers to use import and export natively without Babel for most modern use cases.
If you still require JSX transpilation, SWC (used by Next.js) or ESBuild can provide faster alternatives to Babel.

4. Enhanced React Ecosystem

The React ecosystem now includes powerful libraries like React Server Components (RSC), enabling fine-grained control over what is rendered on the server versus the client.
React’s Streaming SSR offers improved performance for server-side rendering by streaming content to the browser as it is generated.

Recommended Modern Workflow

Use Next.js for Full-Stack Applications:
- Skip the manual setup of Babel, ReactDOMServer, and Express.
- Focus on your application logic instead of configuration.
Precompile Your Code for Production:
- Use build tools like Vite, Webpack, or SWC for preprocessing ES6+ and JSX files before deploying your application.
Leverage React Server Components (RSC):
- Use server components for SSR while dynamically rendering client components as needed.
Embrace Edge Functions (Optional):
- Use platforms like Vercel or Cloudflare Workers to deploy server-rendered content closer to your users for better performance.

When Would This Setup Still Be Useful?

The described approach (using Babel Register, EJS, and Express) may still be relevant if:

You are maintaining a legacy application.
You need a custom server setup for educational purposes.
You are exploring low-level SSR concepts as part of a learning process.

However, for new projects in 2024, modern frameworks like Next.js or Remix are far superior in terms of both developer experience and performance.

Building an Express Server

Learn to set up an Express server for React applications, including configuring Node.js and serving static files.