Inertia.js WordPress Adapter
The unofficial Inertia.js server-side adapter for WordPress.
Installation
Option 1: Install the package via composer. (Recommended)
composer require boxybird/inertia-wordpress
Option 2: Clone or download as a plugin and run composer install before activating in WordPress Admin.
Bare-bones Example Theme
Example Movie CPT WordPress Project
- Demo: https://wp-inertia.andrewrhyand.com
- Theme: https://github.com/boxybird/wordpress-inertia-demo-theme
Inertia Docs
- Links: https://inertiajs.com/links
- Pages: https://inertiajs.com/pages
- Requests: https://inertiajs.com/requests
- Shared Data: https://inertiajs.com/shared-data
- Asset Versioning: https://inertiajs.com/asset-versioning
- Partial Reloads: https://inertiajs.com/partial-reloads
Root Template Example
Location: /wp-content/themes/your-theme/app.php
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<?php wp_head(); ?>
</head>
<body>
<?php bb_inject_inertia(); ?> // Adds Inertia to the page
<?php wp_footer(); ?>
</body>
</html>Root Template File Override
Location: /wp-content/themes/your-theme/functions.php
By default the WordPress adapter will use the app.php from .../your-theme/app.php. If you would like to use a different file name, you can change it. E.g. .../your-theme/layout.php.
<?php
add_action('init', function () {
Inertia::setRootView('layout.php');
});Inertia Function Output Override
By default the bb_inject_inertia() function returns <div id="app" data-page="{...inertiaJsonData}"></div>. If you need to override the div id, you can.
// Override 'id="app"' to 'id="my_app"' and add classes
<?php bb_inject_inertia('my_app', 'bg-blue-100 font-mono p-4'); ?>Inertia Response Examples
Basic
Location: /wp-content/themes/your-theme/index.php
<?php
use BoxyBird\Inertia\Inertia;
global $wp_query;
Inertia::render('Index', [
'posts' => $wp_query->posts,
]);Less Basic
Location: /wp-content/themes/your-theme/index.php
This may look busy, however it can be thought of as a "Controller". It gives you a place to handle all your business logic. Leaving your Javacript files easier to reason about.
<?php
use BoxyBird\Inertia\Inertia;
global $wp_query;
// Build $posts array
$posts = array_map(function ($post) {
return [
'id' => $post->ID,
'title' => get_the_title($post->ID),
'link' => get_the_permalink($post->ID),
'image' => get_the_post_thumbnail_url($post->ID),
'content' => apply_filters('the_content', get_the_content(null, false, $post->ID)),
];
}, $wp_query->posts);
// Build $pagination array
$current_page = isset($wp_query->query['paged']) ? (int) $wp_query->query['paged'] : 1;
$prev_page = $current_page > 1 ? $current_page - 1 : false;
$next_page = $current_page + 1;
$pagination = [
'prev_page' => $prev_page,
'next_page' => $next_page,
'current_page' => $current_page,
'total_pages' => $wp_query->max_num_pages,
'total_posts' => (int) $wp_query->found_posts,
];
// Return Inertia view with data
Inertia::render('Posts/Index', [
'posts' => $posts,
'pagination' => $pagination,
]);Quick Note
You may be wondering what this moster line above does:
'content' => apply_filters('the_content', get_the_content(null, false, $post->ID));Because we can't use the WordPress function the_content() outside of a traditional theme template setup, we need to use get_the_content() instead. However, we first need to apply the filters other plugins and WordPress have registered.
Matter of fact, we can't use any WordPress function that uses echo, and not return.
But don't fret. WordPress typically offers a solution to this caveat: get_the_title() vs the_title(), get_the_ID() vs the_ID(), and so on...
Reference: https://developer.wordpress.org/reference/functions/
Shared data
Location: /wp-content/themes/your-theme/functions.php
add_action('init', function () {
// Synchronously using key/value
Inertia::share('site_name', get_bloginfo('name'));
// Synchronously using array
Inertia::share([
'primary_menu' => array_map(function ($menu_item) {
return [
'id' => $menu_item->ID,
'link' => $menu_item->url,
'name' => $menu_item->title,
];
}, wp_get_nav_menu_items('Primary Menu'))
]);
// Lazily using key/callback
Inertia::share('auth', function () {
if (is_user_logged_in()) {
return [
'user' => wp_get_current_user()
];
}
});
// Lazily on partial reloads
Inertia::share('auth', Inertia::lazy(function () {
if (is_user_logged_in()) {
return [
'user' => wp_get_current_user()
];
}
}));
// Multiple values
Inertia::share([
// Synchronously
'site' => [
'name' => get_bloginfo('name'),
'description'=> get_bloginfo('description'),
],
// Lazily
'auth' => function () {
if (is_user_logged_in()) {
return [
'user' => wp_get_current_user()
];
}
}
]);
});Asset Versioning
Location: /wp-content/themes/your-theme/functions.php
Optional, but helps with cache busting.
add_action('init', function () {
// If you're using Laravel Mix, you can
// use the mix-manifest.json for this.
$version = md5_file(get_stylesheet_directory() . '/mix-manifest.json');
Inertia::version($version);
});