MachineNameController.php

<?php

namespace Drupal\system;

use Drupal\Component\Transliteration\TransliterationInterface;
use Drupal\Core\Access\CsrfTokenGenerator;
use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Controller routines for machine name transliteration routes.
 */
class MachineNameController implements ContainerInjectionInterface {
    
    /**
     * The transliteration helper.
     *
     * @var \Drupal\Component\Transliteration\TransliterationInterface
     */
    protected $transliteration;
    
    /**
     * The token generator.
     *
     * @var \Drupal\Core\Access\CsrfTokenGenerator
     */
    protected $tokenGenerator;
    
    /**
     * Constructs a MachineNameController object.
     *
     * @param \Drupal\Component\Transliteration\TransliterationInterface $transliteration
     *   The transliteration helper.
     * @param \Drupal\Core\Access\CsrfTokenGenerator $token_generator
     *   The token generator.
     */
    public function __construct(TransliterationInterface $transliteration, CsrfTokenGenerator $token_generator) {
        $this->transliteration = $transliteration;
        $this->tokenGenerator = $token_generator;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('transliteration'), $container->get('csrf_token'));
    }
    
    /**
     * Transliterates a string in given language. Various postprocessing possible.
     *
     * @param \Symfony\Component\HttpFoundation\Request $request
     *   The input string and language for the transliteration.
     *   Optionally may contain the replace_pattern, replace, lowercase parameters.
     *
     * @return \Symfony\Component\HttpFoundation\JsonResponse
     *   The transliterated string.
     */
    public function transliterate(Request $request) {
        $text = $request->query
            ->get('text');
        $langcode = $request->query
            ->get('langcode');
        $replace_pattern = $request->query
            ->get('replace_pattern');
        $replace_token = $request->query
            ->get('replace_token');
        $replace = $request->query
            ->get('replace');
        $lowercase = $request->query
            ->get('lowercase');
        $transliterated = $this->transliteration
            ->transliterate($text, $langcode, '_');
        if ($lowercase) {
            $transliterated = mb_strtolower($transliterated);
        }
        if (isset($replace_pattern) && isset($replace)) {
            if (!isset($replace_token)) {
                throw new AccessDeniedHttpException("Missing 'replace_token' query parameter.");
            }
            elseif (!$this->tokenGenerator
                ->validate($replace_token, $replace_pattern)) {
                throw new AccessDeniedHttpException("Invalid 'replace_token' query parameter.");
            }
            // Quote the pattern delimiter and remove null characters to avoid the e
            // or other modifiers being injected.
            $transliterated = preg_replace('@' . strtr($replace_pattern, [
                '@' => '\\@',
                chr(0) => '',
            ]) . '@', $replace, $transliterated);
        }
        return new JsonResponse($transliterated);
    }

}