Before PHP transform

Registering a plugin before usePHP() lets you modify the raw source before the plugin escapes PHP fragments and runs Vite's HTML transforms.

When to use this

• Inject shared PHP variables or configuration into every entry.
• Add server-side logic that should be evaluated by PHP.
• Pre-process the PHP source based on the request context.

Example: inject a PHP config block

// vite.config.ts
import { defineConfig } from 'vite';
import usePHP from 'vite-plugin-php';

export default defineConfig({
    plugins: [
        {
            name: 'inject-config',
            transformIndexHtml: {
                order: 'pre',
                handler(html, ctx) {
                    return html.replace(
                        '</body>',
                        `<?php $appVersion = '${process.env.npm_package_version}'; ?>\n</body>`,
                    );
                },
            },
        },
        usePHP(),
    ],
});

Because this plugin runs before usePHP() with order: 'pre', the injected PHP code will be escaped, survive Vite transforms and eventually be executed by the PHP server.

Example: conditional environment banner

{
    name: 'env-banner',
    transformIndexHtml: {
        order: 'pre',
        handler(html, ctx) {
            if (process.env.NODE_ENV === 'development') {
                return html.replace(
                    '</body>',
                    `<div style="background:red;color:white;padding:0.5rem;">DEV MODE</div>\n</body>`,
                );
            }
        },
    },
}

Important caveat

The raw source at this point still contains the original PHP tags. Returning plain HTML that contains <?php ... ?> is fine because the plugin will escape it next.