ContextualController.php in Drupal 10        
                          
                  
                        
  
  
  
  
File
  core/modules/contextual/src/ContextualController.php
  
    View source  
  <?php
namespace Drupal\contextual;
use Drupal\Component\Utility\Crypt;
use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
use Drupal\Core\Render\RendererInterface;
use Drupal\Core\Site\Settings;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
class ContextualController implements ContainerInjectionInterface {
  
  protected $renderer;
  
  public function __construct(RendererInterface $renderer) {
    $this->renderer = $renderer;
  }
  
  public static function create(ContainerInterface $container) {
    return new static($container
      ->get('renderer'));
  }
  
  public function render(Request $request) {
    if (!$request->request
      ->has('ids')) {
      throw new BadRequestHttpException('No contextual ids specified.');
    }
    $ids = $request->request
      ->all('ids');
    if (!$request->request
      ->has('tokens')) {
      throw new BadRequestHttpException('No contextual ID tokens specified.');
    }
    $tokens = $request->request
      ->all('tokens');
    $rendered = [];
    foreach ($ids as $key => $id) {
      if (!isset($tokens[$key]) || !hash_equals($tokens[$key], Crypt::hmacBase64($id, Settings::getHashSalt() . \Drupal::service('private_key')
        ->get()))) {
        throw new BadRequestHttpException('Invalid contextual ID specified.');
      }
      $element = [
        '#type' => 'contextual_links',
        '#contextual_links' => _contextual_id_to_links($id),
      ];
      $rendered[$id] = $this->renderer
        ->renderRoot($element);
    }
    return new JsonResponse($rendered);
  }
}