Webpack hello world

In this example we're going to create a simple HTML page with some text and two buttons, then attach a click listener to each button that changes the text displayed - but we're going to do it using PHP that we'll pre-transpile to JavaScript using Webpack and the Uniter loader.

If you're in a hurry, you can check out the finished example here.

Step 1

Install all the tools you're going to need:

npm install --save-dev phpify source-map-loader transform-loader babel-loader babel-core babel-preset-env webpack

Step 2

Add your PHPify config to package.json:

    "phpify": {
        "phpToJS": {
            "sync": true

The sync option enables the synchronous mode for Uniter. In most cases you'll want to stick to synchronous mode, but if you need to call something that may block like usleep(...), you'll need to switch to async mode. See the [async vs sync mode]() section.

Step 3

Create your HTML page index.html:

<!DOCTYPE html>
        <title>My web page</title>
        <h1>My web page</h1>

        <p id="myMessage">Click a button to change me!</p>

        <button type="button" id="helloButton">Hello!</button>
        <button type="button" id="worldButton">World!</button>

        <script src="./dist/my_bundle.js"></script>

Step 4

Create your PHP file that will return a closure to attach the buttons' behaviours, binder.php:


print 'Hello from binder.php!';

return function ($document) {
    $messageBox = $document->getElementById('myMessage');

    $document->getElementById('helloButton')->addEventListener('click', function () use ($messageBox) {
        $messageBox->textContent = 'You clicked Hello!';

    $document->getElementById('worldButton')->addEventListener('click', function () use ($messageBox) {
        $messageBox->textContent = 'You clicked World!';

Step 5

Create your entrypoint JS file my_app.js:

// Fetch the PHP module (but don't actually run it yet)
const binderModule = require('./binder.php')();

// Hook stdout and stderr up to the console
binderModule.getStdout().on('data', function (data) {
binderModule.getStderr().on('data', function (data) {

// Run the PHP module, capture its result Closure
// and cast it to a JavaScript function we can call
const binder = binderModule.execute().getNative();

// Call the PHP closure function returned from binder.php, from JavaScript!

Step 6

Create your Webpack config file webpack.config.js:

module.exports = {
    context: __dirname,
    entry: './my_app',
    module: {
        rules: [
                // PHPify transpiles your PHP code to JavaScript,
                // so Webpack can include it in your JS bundle for you
                // and it can be run in the browser.
                test: /\.php$/,
                use: 'transform-loader?phpify'
                // PHPify is (at the moment) a Browserify transform and not
                // a Webpack loader, so we need to extract the source map
                // it generates and apply it to Webpack's for it to work properly.
                test: /\.php/,
                use: 'source-map-loader',
                enforce: 'post'
                // This is the standard Babel setup to enable ES5 support
                test: /\.js$/,
                exclude: /\bnode_modules\b/,
                use: {
                    loader: 'babel-loader?presets=env'
    output: {
        path: __dirname + '/dist/',
        filename: 'my_bundle.js'

Step 7

Build your bundle with Webpack:

node_modules/.bin/webpack --devtool source-map

You'll probably find it handy to add an NPM script for your webpack build command above.

There's one in the complete demo repository for this example.

Step 8

Open index.html in a browser!