Server Side Rendering with React

Gufran Mirza
Software Engineer @Continuum

 

Twitter: _imGufran

Agenda

  • Overview - React Client Side Rendering

  • Overview - React Server Side Rendering

  • Performance CSR vs SSR

  • Live Demo

  • Discussion

What?

 

Server-Side Rendering  is the ability of a front-end framework to render markup while running on a back-end system.

Why?

  • Performance benefit for our customers
  • Faster times for the initial page render

  • Consistent SEO performance

How?

  • Express-JS/Hapi-JS with NodeJS
  • React - Supports both CSR / SSR
  • ReactDOM - renderToString()

Overview - React Client Side Rendering

<!doctype html>
<html lang="en">

  <head>
      <meta charset="utf-8" />
      <link rel="shortcut icon" href="/favicon.ico" />
      <meta name="viewport" content="width=device-width,initial-scale=1,shrink-to-fit=no" />
      <title>React App</title>
      <link href="/static/css/main.css" rel="stylesheet">
      <script src="/static/js/main.js"></script>
  </head>

  <body>
      <div id="root"></div>
  </body>

</html>

Generated Markup (SPA)

Browser downloads the Javascript and then executes it to generate the Content

 

Overview - React Client Side Rendering

Let`s Understand CSR with Example Page

Overview - React Client Side Rendering

Pup vs. Pup - GET #1

GET - /

SERVER

index.html

<!DOCTYPE html>
<html>
  <head>
    <title>Pup vs Pup</title>
    <link rel="stylesheet" href="/css/style.css">
    <script src="public/bundle.js" defer></script>
  </head>
  <body>
    <div id="app"></div>
  </body>
</html>

Overview - React Client Side Rendering

Pup vs. Pup - View #1

User View

Overview - React Client Side Rendering

Pup vs. Pup - GET #2

GET - /public/bundle.js

SERVER

bundle.js

/******/ (function(modules) { // webpackBootstrap
/******/ 	// The module cache
/******/ 	var installedModules = {};
/******/
/******/ 	// The require function
/******/ 	function __webpack_require__(moduleId) {
/******/
/******/ 		// Check if module is in cache
/******/ 		if(installedModules[moduleId])
/******/ 			return installedModules[moduleId].exports;
/******/
/******/ 		// Create a new module (and put it into the cache)
/******/ 		var module = installedModules[moduleId] = {
/******/ 			exports: {},

....

21,547 MORE LINES OF CODE

Overview - React Client Side Rendering

Pup vs. Pup - View #2

  • 21,500 lines of javascript parsed
  • Script execution begins, React.DOM renders!

But where are the pups???

Overview - React Client Side Rendering

PuppyDB

Pup vs. Pup - GET #3

GET - /api/puppies

Overview - React Client Side Rendering

Client Side React - Overview

GET - /

1

SERVER

GET - /bundle.js

2

React.DOM Render

3

React.DOM Render

5

GET - api/puppies

4

"First Meaningful Paint"

GET - /style.css

Overview - React Client Side Rendering

Overview - React Server Side Rendering

<!doctype html>
<html lang="en">
  <head>
      <meta charset="utf-8" />
      <link rel="shortcut icon" href="/favicon.ico" />
      <meta name="viewport" content="width=device-width,initial-scale=1,shrink-to-fit=no" />
      <title>React App</title>
      <link href="/static/css/main.css" rel="stylesheet">
      <script src="/static/js/main.js"></script>
  </head>

  <body>
      <div id="root"></div>
      <div id="root">
        <div class="App" data-reactroot="">
            <header class="App-header">
                <img src="[object Object]" class="App-logo" alt="logo" />
                <p>Edit <code>src/App.js</code> and save to reload.</p>
                <a class="App-link" href="https://reactjs.org" target="_blank" rel="noopener noreferrer">Learn React</a>
            </header>
        </div>
    </div>
  </body>
</html>

Generated Markup (SSR)

Server (NodeJS) renders the App and generates the content at server-side and returns the generated content

Overview - React Server Side Rendering

Server Side React - Overview

GET - /

1

SERVER

React.DOM Render

2

  • Server gets request
  • Server GETs data from DB**
  • Server renders HTML

 

  • React DOM renders again on client side
     

  • Verifies state, adds click handlers

Downloads js

Overview - React Server Side Rendering

Performance - CSR vs SSR

Performance - CSR vs SSR

Performance - CSR vs SSR

Performance - CSR vs SSR

Light Hose Report - CSR

Performance - CSR vs SSR

Performance Report - CSR

Performance - CSR vs SSR

Light Hose Report - SSR

Performance - CSR vs SSR

Performance Report - SSR

Live Demo!

Discussion

Server Side Rendering with React

By Gufran Mirza

Server Side Rendering with React

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