December 13, 2017

Inlining a React/Material-UI web app

This guide was originally posted on Medium. I am reposting here to test the features of my new Hugo website.

This guide is pretty simple and straightforward, it is not specific to React, but the example project uses React and Material UI. Before setting up a build system like this, you should at least be familiar with the UNIX terminal, JavaScript, CSS, and HTML.

Inlining can be done with other tools, like gulp or create-react-app (or next year’s big new JavaScript framework), so you should explore your options. For me, the biggest appeal of npm scripts (npm run) is that it’s simple, and doesn’t have any dependencies besides npm.

Node package manager (npm)

npm is used to download packages and run build commands, it can be downloaded as part of nodejs:

Creating a new project

Make a project folder and initialize npm inside of it:

$ mkdir ReactCalculator
$ cd ReactCalculator/
$ npm init

You can safely press enter through most/all questions. This is my resulting package.json:

  "name": "reactcalculator",
  "version": "0.1.0",
  "description": "An example application",
  "main": "index.html",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  "author": "olehermanse",
  "license": "MIT"

Note the scripts field; this is where we will add build commands later.

Installing packages

Use npm to install dependencies:

$ npm install --save material-ui react react-dom
$ npm install --save-dev babel-core babel-loader babelify browserify
$ npm install --save-dev babel-preset-env babel-preset-react babel-preset-stage-0
$ npm install --save-dev express inline-source inline-source-cli uglify

Tip: The–save flags add the packages to package.json , if you’re using the example project you can install them by running npm install.

A simple HTML skeleton

Our app will consist of HTML, CSS, and JavaScript files. The build system will compile all of these into a single file, index.html, using the inline-source package. Let’s create some empty files:

$ mkdir src
$ touch src/main.html src/main.css src/main.jsx

Let’s add some content to src/main.html:

<!doctype html>
  <link inline rel="stylesheet" type="text/css" href="main.css" />
  <div id=body_main class=body_main>
  <script inline src="main.js"></script>

Note the inline keyword in both <link> and <script> tags. inline-source will replace these tags with the contents of the referenced files. The body_main div content will be controlled by JavaScript(React).

Content to inline

To see the effects of inlining, we should add some simple content to the JavaScript and CSS files:

$ echo '* { background-color: #CCCCCC; }' > src/main.css
$ echo 'document.getElementById("body_main").innerHTML = "Hello, JavaScript";' > src/main.jsx

A simple build system using inline-source In package.json we can add build commands in the scripts section:

"scripts": {
  "prebuild": "mkdir -p ./build",
  "build:css": "cp ./src/main.css ./build/main.css",
  "build:js": "cp ./src/main.jsx ./build/main.js",
  "build:inline": "inline-source --root ./build ./src/main.html > build/index.html",
  "build": "npm run build:js && npm run build:css && npm run build:inline"

prebuild runs before build, making sure the build folder exists. build:js and build:css copy the files into the build folder. They are then inlined using the inline-source command.

Now, build:

$ npm run build

That’s it. build/index.html now contains both HTML, CSS, and JavaScript:

<!doctype html>
  <style type="text/css">* { background-color: #CCCCCC; }
  <div id=body_main class=body_main>
  <script>document.getElementById("body_main").innerHTML = "Hello, JavaScript";

You don’t need a development server, you can just open build/index.html in your browser of choice. The background color should be grey, and the text should say “Hello, JavaScript”.

Tip: Inlining is not limited to JavaScript and CSS. The inline-source package can also inline images. There are more packages for inlining other data, like JSON.

React, babel, JSX, browserify and uglify

When writing React apps and components, JSX is preferred over plain JavaScript. babel can be used to transpile JSX to javascript. It also translates newer syntax (ES6) to old syntax equivalents. Another piece of magic is browserify, which bundles dependencies. You can require('modules') and it just works. The final part of our javascript build command will be uglifyjs which reduces the size of the javascript file before inlining.

The build:js command in package.json should look something like this:

browserify -t [ babelify  --presets [ env stage-0 react ] ] src/main.jsx | uglifyjs -mc > build/main.js

Run the build command again, npm run build, to make sure you haven’t introduced any errors. The resulting index.html should look identical, we haven’t made any changes to the content, but the build system is now ready to build a React app written in JSX and ES6.

React app with Material-UI components

I’ve created a simple example project to show how this build system works with JSX and Material-UI code. Feel free to download from GitHub and experiment yourself. Teaching React or Material-UI is outside the scope of this tutorial. Excellent documentation is available for both, see the links below.

Learn more

Example app available on GitHub:

Inline-source documentation:

Material-UI documentation:

React (and JSX) documentation:

An overview of JavaScript build systems:

More information on npm scripts:

© Ole Herman Schumacher Elgesem 2021

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