Goal: Create WordPress plugin which will inject React based web app\widget into normal WordPress page\post\sidebar.
This is useful when you need to create an complex fully interactive widget\app like calculator for example, and you want it to be a part of WordPress page.
In this article I’ll describe one of the approaches, though it may be not perfect, we’ll dig deeper into other build approaches in next articles.
Let’s split our big task into sub-tasks to better understand how we achieve it:
- Create WordPress plugin
- it will enqueue our js\css and register
shortcode
to render root element of React app - yes shortcodes are old school approach (compared to Gutenberg Blocks) but they work well for this use case and we keep it simpler for now.
- it will also pass in App’s settings via data attribute of root element.
- it will enqueue our js\css and register
- Generate React app via
npx create-react-app
- the idea is to utilize a ready to use solution for scaffolding and Webpack configuration, so newbies like me 🙂 in react world could follow standard React tutorials to build his first React App.
- also you can use approach explained in this article to simply inject your existing React App, generated via
npx create-react-app
into WP based site.
- Modify build\start npm scripts to work well with WordPress.
- by default react build Webpack’s configuration will generate js files split in chunks – it makes it harder to link them via
wp_enqueue_scripts
as we used to in WordPress. - so we’ll write a code which will partially override config and Webpack will generate js\css which will be easy to use in WP.
- by default react build Webpack’s configuration will generate js files split in chunks – it makes it harder to link them via
- Write JSX\React code and build it.
Result plugin can be fetched from github https://github.com/MikhailRoot/embeded-react-app-in-wp
1. Create WordPress plugin
It will register a shortcode and enqueue scripts and styles for our React App.
https://github.com/MikhailRoot/embeded-react-app-in-wp/blob/master/plugin.php
NB: I use
define('ENV_DEV', true); // in wp-config.php
to load generated by yarn start
css\js files while development, set it to false
when you need to use css\js generated via yarn build
.
In a shortcode I pass in json string of settings as data-default-settings
attribute for our App’s root element.
2. Generate React App
In your new plugin’s directory simply run npx create-react-app app
and wait a bit.
We’ll use yarn add
for the sake of brevity but you can use npm
as well. Just pick one (anyway you can switch back any time if needed).
Let’s cleanup a bit via removing redundant files from src
directory of app. These are:
logo.svg
– because in WordPress we handle images URLs differently – you can use relative to plugin’s path links to images.serviceWorker.js
As well as references to them in index.js
and App.js
You can remove all files inside /app/public
except index.html
as we don’t need them.
Remove .git
directory inside react app’s folder – as you’ll probably want to track changes via git but for a whole plugin and not just react part of it. And in .gitignore
remove line
/build
So our main.js
and main.css
files which are result of build process will be tracked with git.
Next step is optional – we’ll install node-sass
I just prefer to work with SCSS files rather then plain CSS, so in case you like it as well – just cd
to your newly generated react app directory and then run yarn add node-sass
as described here https://create-react-app.dev/docs/adding-a-sass-stylesheet/
Create scss
folder under src
and move css files into it, renaming them to .scss
and change imports of these files in js to point to our new .scss
files like:
import './scss/App.scss';
in App.js
, and
import './scss/index.scss';
for index.js
3. Modify build\start npm scripts to work well with WordPress
In your React App’s directory, run yarn add rewire --dev
– we use rewire
to be able to redefine webpack.config provided by create-react-app
boilerplate without a need to eject
react app or modify config files which reside in node_modules
Now create new directory called scripts
– here we’ll set our JS files which will do magic for us.
start-non-split.js
– this file will change Webpack config on fly so that it will not split JS code in chunks and will not inject hash into filename.
const externals = require( './externals' );
const rewire = require( 'rewire' );
const defaults = rewire( 'react-scripts/scripts/start.js' );
const configFactory = defaults.__get__( 'configFactory' );
defaults.__set__( 'configFactory', ( env ) => {
const config = configFactory( env );
config.externals = {
...config.externals,
...externals,
};
config.optimization.splitChunks = {
cacheGroups: {
default: false,
},
};
config.optimization.runtimeChunk = false;
config.output.filename = 'static/js/[name].js';
config.output.chunkFilename = 'static/js/[name].js';
return config;
} );
build-non-split.js
– this is used for building production js\css files it will again build them as single files making it easier to link in WP.
const externals = require( './externals' );
const rewire = require( 'rewire' );
const MiniCssExtractPlugin = require( 'mini-css-extract-plugin' );
const defaults = rewire( 'react-scripts/scripts/build.js' );
const config = defaults.__get__( 'config' );
/* we inject our Externals to keep our bundles clean and slim */
config.externals = {
...config.externals,
...externals,
};
/*
* we set jsonFunction of webpack to our custom one
* so multiple js bundles built with webpack could be safely loaded,
* as we are aware that our plugin isn't the only one which can be potentially built with webpack.
*/
config.output.jsonpFunction = 'YourReactApp_webpackJsonpjs';
/* we disable chunks optimization because we want single js\css file to be loaded by plugin. */
config.optimization.splitChunks = {
cacheGroups: {
default: false,
},
};
config.optimization.runtimeChunk = false;
config.output.filename = 'static/js/[name].js';
config.output.chunkFilename = 'static/js/[name].js';
/*
* lets find `MiniCssExtractPlugin` type of object in plugins array and redefine it's options.
* And remove all unnecessary plugins.
*/
const disabledPlugins = [
'GenerateSW',
'ManifestPlugin',
'InterpolateHtmlPlugin',
'InlineChunkHtmlPlugin',
'HtmlWebpackPlugin',
];
config.plugins = config.plugins.reduce( ( plugins, pluginItem ) => {
if ( disabledPlugins.indexOf( pluginItem.constructor.name ) >= 0 ) {
return plugins;
}
if ( pluginItem instanceof MiniCssExtractPlugin ) {
plugins.push(
new MiniCssExtractPlugin( {
filename: 'static/css/[name].css',
chunkFilename: 'static/css/[name].css',
} )
);
} else {
plugins.push( pluginItem );
}
return plugins;
}, [] );
externals.js
– this file contains shared scripts which can be provided by WP Core so we don’t need them to be bundled into our build.
module.exports = {
react: 'React',
'react-dom': 'ReactDOM',
};
In my case after I’ve marked React
and ReactDOM
as external ones JS bundle’s size decreased from 160kb to 56kb – those get’s loaded from wp-includes
as a dependency any way, but imagine you have bunch of such Apps and each will load extra version of bundled React library. To overcome this we mark them as external – this way we keep our bundles clean and light, and at the same time we leverage WordPress scripts dependency manager to link necessary dependencies for us.
Then open package.json
file and in scripts
section update start
command to
"start": "node ./scripts/start-non-split.js",
and build
command to
"build": "node ./scripts/build-non-split.js"
So your package.json
file will look like this:
{
"name": "app",
"version": "0.1.0",
"private": true,
"dependencies": {
"@testing-library/jest-dom": "^4.2.4",
"@testing-library/react": "^9.3.2",
"@testing-library/user-event": "^7.1.2",
"react": "^16.13.1",
"react-dom": "^16.13.1",
"react-scripts": "3.4.1"
},
"scripts": {
"start": "node ./scripts/start-non-split.js",
"build": "node ./scripts/build-non-split.js",
"test": "react-scripts test",
"eject": "react-scripts eject"
},
"eslintConfig": {
"extends": "react-app"
},
"browserslist": {
"production": [
">0.2%",
"not dead",
"not op_mini all"
],
"development": [
"last 1 chrome version",
"last 1 firefox version",
"last 1 safari version"
]
},
"devDependencies": {
"node-sass": "^4.14.0",
"rewire": "^5.0.0"
}
}
4. Write JSX\React code and build it.
Now we are almost ready, let’s update index.js
file which initializes our React app on root element inserted via shortcode.
import React from "react";
import ReactDOM from "react-dom";
import "./scss/index.scss";
import App from "./App";
const rootEl = document.getElementById("md-react-app");
if (rootEl) {
const settings = JSON.parse( rootEl.getAttribute( 'data-default-settings' ) );
ReactDOM.render(
<React.StrictMode>
<App settings={settings} />
</React.StrictMode>,
rootEl
);
}
Here we also read initialization settings data provided by WP, and pass them into App as prop.
If you’ll use Redux you can use these data to generate initial state for App.
Let’s update our App.js
file to utilize our settings from props.
import React from 'react';
import './scss/App.scss';
function App(props) {
const items = props.settings.some_items || [];
return (
<div className="App">
<header className="App-header">
<h1>{ props.settings.l18n.main_title }</h1>
<ul>
{
items.map((item, index)=>{
return (
<li key={index}>{item}</li>
)
})
}
</ul>
<p>
Edit <code>src/App.js</code> and save to reload.
</p>
<a
className="App-link"
href="https://reactjs.org"
target="_blank"
rel="noopener noreferrer"
>
Learn React
</a>
</header>
</div>
);
}
export default App;
Now we are ready to test everything together.
- activate our plugin and place
[md-react-app]
shortcode on page. - in terminal
cd
to plugin’s directory/app
and runyarn build
– it will build js\css then just open a page where you’ve placed a shortcode and app will be rendered there.
For development:
- add
define('ENV_DEV', true);
to yourwp-config.php
- in plugin’s
/app
sub directory runyarn start
it will build css\js and spin up a dev server to serve updated css\js whenever you make change in source files. (it doesn’t support live reloading yet but for quickstart it’s enough). - It will also open a new tab in browser leading to localhost:3000 and showing error message that
React is not defined
just close and ignore it. It says React is not defined just because we’ve declared it as external and we haven’t bundled it into our resultmain.js
- It will work inside WordPress page because we’ve declared
wp-element
as dependency in our plugin, so WordPress will load React on it’s own. - So just refresh your WordPress page where you’ve placed our new shortcode and here’s your React App inside WordPress page.
- NB: in
ENV_DEV true
mode you need toyarn start
otherwise it will not be able to load css\js, set it tofalse
or comment out for production.
Happy codding 🙂