composer-request-and-htmlpurifier.php

<?php
require_once __DIR__.'/vendor/autoload.php';

use Symfony\Component\HttpFoundation\Request;

$request = Request::createFromGlobals();

$dirty_html = $request->get('dirty_input');

$config = HTMLPurifier_Config::createDefault();
$purifier = new HTMLPurifier($config);
$clean_html = $purifier->purify($dirty_html);

?>