client_hints-8.x-1.0-alpha3/src/Controller/Redirect.php

<?php

namespace Drupal\client_hints\Controller;

use Drupal\client_hints\Service\ClientHints;
use Drupal\Core\Cache\CacheableRedirectResponse;
use Drupal\Core\DependencyInjection\ContainerInjectionInterface;
use Drupal\Core\Render\RenderContext;
use Symfony\Component\DependencyInjection\ContainerInterface;
use Symfony\Component\HttpFoundation\Request;

/**
 * Redirect controller.
 */
class Redirect implements ContainerInjectionInterface {

  /**
   * The client hints service.
   *
   * @var \Drupal\client_hints\Service\ClientHints
   */
  protected $clientHints;

  /**
   * Constructs a redirect controller.
   *
   * @param \Drupal\client_hints\Service\ClientHints $client_hints
   *   The client hints service.
   */
  public function __construct(ClientHints $client_hints) {
    $this->clientHints = $client_hints;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static($container->get('client_hints'));
  }

  /**
   * Image URL redirect.
   */
  public function image(Request $request) {
    // Get request parameters.
    $image_uri = $request->query->get('file');
    $dpr = $request->query->getInt('dpr', 1);
    $width = $request->query->getInt('width', 0);

    // Get corresponding image style redirect URL.
    // Generating the URL for a URI using a stream wrapper ends up calling
    // StreamWrapperInterface::getExternalUrl(), which in turn can result in
    // early rendering, for example for the private stream. Therefore, we
    // generate the URL inside of a fake render context and subsequently add the
    // "leaked" cacheability metadata to the response.
    /* @see \Drupal\Core\StreamWrapper\PrivateStream::getExternalUrl() */
    $context = new RenderContext();
    $image_style_url = \Drupal::service('renderer')->executeInRenderContext($context, function () use ($image_uri, $dpr, $width) {
      return $this->clientHints->getImageRedirectUrl($image_uri, $dpr, $width);
    });

    $response = new CacheableRedirectResponse($image_style_url);
    // Add cacheability metadata.
    $response->getCacheableMetadata()->addCacheContexts(['url.query_args:file', 'url.query_args:dpr', 'url.query_args:width']);
    if (!$context->isEmpty()) {
      $response->addCacheableDependency($context->pop());
    }

    return $response;
  }

}