class ImageStyleDownloadController in Drupal 8

Same name and namespace in other branches

9 core/modules/image/src/Controller/ImageStyleDownloadController.php \Drupal\image\Controller\ImageStyleDownloadController

Defines a controller to serve image styles.

Hierarchy

class \Drupal\Core\Controller\ControllerBase implements ContainerInjectionInterface uses LoggerChannelTrait, MessengerTrait, LinkGeneratorTrait, RedirectDestinationTrait, UrlGeneratorTrait, StringTranslationTrait
- class \Drupal\system\FileDownloadController
  - class \Drupal\image\Controller\ImageStyleDownloadController

Expanded class hierarchy of ImageStyleDownloadController

File

core/modules/image/src/Controller/ImageStyleDownloadController.php, line 22

Namespace

Drupal\image\Controller

View source

class ImageStyleDownloadController extends FileDownloadController {

  /**
   * The lock backend.
   *
   * @var \Drupal\Core\Lock\LockBackendInterface
   */
  protected $lock;

  /**
   * The image factory.
   *
   * @var \Drupal\Core\Image\ImageFactory
   */
  protected $imageFactory;

  /**
   * A logger instance.
   *
   * @var \Psr\Log\LoggerInterface
   */
  protected $logger;

  /**
   * Constructs a ImageStyleDownloadController object.
   *
   * @param \Drupal\Core\Lock\LockBackendInterface $lock
   *   The lock backend.
   * @param \Drupal\Core\Image\ImageFactory $image_factory
   *   The image factory.
   * @param \Drupal\Core\StreamWrapper\StreamWrapperManagerInterface $stream_wrapper_manager
   *   The stream wrapper manager.
   */
  public function __construct(LockBackendInterface $lock, ImageFactory $image_factory, StreamWrapperManagerInterface $stream_wrapper_manager = NULL) {
    parent::__construct($stream_wrapper_manager);
    $this->lock = $lock;
    $this->imageFactory = $image_factory;
    $this->logger = $this
      ->getLogger('image');
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static($container
      ->get('lock'), $container
      ->get('image.factory'), $container
      ->get('stream_wrapper_manager'));
  }

  /**
   * Generates a derivative, given a style and image path.
   *
   * After generating an image, transfer it to the requesting agent.
   *
   * @param \Symfony\Component\HttpFoundation\Request $request
   *   The request object.
   * @param string $scheme
   *   The file scheme, defaults to 'private'.
   * @param \Drupal\image\ImageStyleInterface $image_style
   *   The image style to deliver.
   *
   * @return \Symfony\Component\HttpFoundation\BinaryFileResponse|\Symfony\Component\HttpFoundation\Response
   *   The transferred file as response or some error response.
   *
   * @throws \Symfony\Component\HttpKernel\Exception\NotFoundHttpException
   *   Thrown when the file request is invalid.
   * @throws \Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException
   *   Thrown when the user does not have access to the file.
   * @throws \Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException
   *   Thrown when the file is still being generated.
   */
  public function deliver(Request $request, $scheme, ImageStyleInterface $image_style) {
    $target = $request->query
      ->get('file');
    $image_uri = $scheme . '://' . $target;

    // Check that the style is defined, the scheme is valid, and the image
    // derivative token is valid. Sites which require image derivatives to be
    // generated without a token can set the
    // 'image.settings:allow_insecure_derivatives' configuration to TRUE to
    // bypass the latter check, but this will increase the site's vulnerability
    // to denial-of-service attacks. To prevent this variable from leaving the
    // site vulnerable to the most serious attacks, a token is always required
    // when a derivative of a style is requested.
    // The $target variable for a derivative of a style has
    // styles/<style_name>/... as structure, so we check if the $target variable
    // starts with styles/.
    $valid = !empty($image_style) && $this->streamWrapperManager
      ->isValidScheme($scheme);
    if (!$this
      ->config('image.settings')
      ->get('allow_insecure_derivatives') || strpos(ltrim($target, '\\/'), 'styles/') === 0) {
      $valid &= hash_equals($image_style
        ->getPathToken($image_uri), $request->query
        ->get(IMAGE_DERIVATIVE_TOKEN, ''));
    }
    if (!$valid) {

      // Return a 404 (Page Not Found) rather than a 403 (Access Denied) as the
      // image token is for DDoS protection rather than access checking. 404s
      // are more likely to be cached (e.g. at a proxy) which enhances
      // protection from DDoS.
      throw new NotFoundHttpException();
    }
    $derivative_uri = $image_style
      ->buildUri($image_uri);
    $headers = [];

    // If using the private scheme, let other modules provide headers and
    // control access to the file.
    if ($scheme == 'private') {
      $headers = $this
        ->moduleHandler()
        ->invokeAll('file_download', [
        $image_uri,
      ]);
      if (in_array(-1, $headers) || empty($headers)) {
        throw new AccessDeniedHttpException();
      }
    }

    // Don't try to generate file if source is missing.
    if (!file_exists($image_uri)) {

      // If the image style converted the extension, it has been added to the
      // original file, resulting in filenames like image.png.jpeg. So to find
      // the actual source image, we remove the extension and check if that
      // image exists.
      $path_info = pathinfo($image_uri);
      $converted_image_uri = $path_info['dirname'] . DIRECTORY_SEPARATOR . $path_info['filename'];
      if (!file_exists($converted_image_uri)) {
        $this->logger
          ->notice('Source image at %source_image_path not found while trying to generate derivative image at %derivative_path.', [
          '%source_image_path' => $image_uri,
          '%derivative_path' => $derivative_uri,
        ]);
        return new Response($this
          ->t('Error generating image, missing source file.'), 404);
      }
      else {

        // The converted file does exist, use it as the source.
        $image_uri = $converted_image_uri;
      }
    }

    // Don't start generating the image if the derivative already exists or if
    // generation is in progress in another thread.
    if (!file_exists($derivative_uri)) {
      $lock_name = 'image_style_deliver:' . $image_style
        ->id() . ':' . Crypt::hashBase64($image_uri);
      $lock_acquired = $this->lock
        ->acquire($lock_name);
      if (!$lock_acquired) {

        // Tell client to retry again in 3 seconds. Currently no browsers are
        // known to support Retry-After.
        throw new ServiceUnavailableHttpException(3, 'Image generation in progress. Try again shortly.');
      }
    }

    // Try to generate the image, unless another thread just did it while we
    // were acquiring the lock.
    $success = file_exists($derivative_uri) || $image_style
      ->createDerivative($image_uri, $derivative_uri);
    if (!empty($lock_acquired)) {
      $this->lock
        ->release($lock_name);
    }
    if ($success) {
      $image = $this->imageFactory
        ->get($derivative_uri);
      $uri = $image
        ->getSource();
      $headers += [
        'Content-Type' => $image
          ->getMimeType(),
        'Content-Length' => $image
          ->getFileSize(),
      ];

      // \Drupal\Core\EventSubscriber\FinishResponseSubscriber::onRespond()
      // sets response as not cacheable if the Cache-Control header is not
      // already modified. We pass in FALSE for non-private schemes for the
      // $public parameter to make sure we don't change the headers.
      return new BinaryFileResponse($uri, 200, $headers, $scheme !== 'private');
    }
    else {
      $this->logger
        ->notice('Unable to generate the derived image located at %path.', [
        '%path' => $derivative_uri,
      ]);
      return new Response($this
        ->t('Error generating image.'), 500);
    }
  }

}

Members

Name	Modifiers	Type	Description	Overrides
ControllerBase::$configFactory	protected	property	The configuration factory.
ControllerBase::$currentUser	protected	property	The current user service.	1
ControllerBase::$entityFormBuilder	protected	property	The entity form builder.
ControllerBase::$entityManager	protected	property	The entity manager.
ControllerBase::$entityTypeManager	protected	property	The entity type manager.
ControllerBase::$formBuilder	protected	property	The form builder.	2
ControllerBase::$keyValue	protected	property	The key-value storage.	1
ControllerBase::$languageManager	protected	property	The language manager.	1
ControllerBase::$moduleHandler	protected	property	The module handler.	2
ControllerBase::$stateService	protected	property	The state service.
ControllerBase::cache	protected	function	Returns the requested cache bin.
ControllerBase::config	protected	function	Retrieves a configuration object.
ControllerBase::container	private	function	Returns the service container.
ControllerBase::currentUser	protected	function	Returns the current user.	1
ControllerBase::entityFormBuilder	protected	function	Retrieves the entity form builder.
ControllerBase::entityManager Deprecated	protected	function	Retrieves the entity manager service.
ControllerBase::entityTypeManager	protected	function	Retrieves the entity type manager.
ControllerBase::formBuilder	protected	function	Returns the form builder service.	2
ControllerBase::keyValue	protected	function	Returns a key/value storage collection.	1
ControllerBase::languageManager	protected	function	Returns the language manager service.	1
ControllerBase::moduleHandler	protected	function	Returns the module handler.	2
ControllerBase::redirect	protected	function	Returns a redirect response object for the specified route. Overrides UrlGeneratorTrait::redirect
ControllerBase::state	protected	function	Returns the state storage service.
FileDownloadController::$streamWrapperManager	protected	property	The stream wrapper manager.
FileDownloadController::download	public	function	Handles private file transfers.
ImageStyleDownloadController::$imageFactory	protected	property	The image factory.
ImageStyleDownloadController::$lock	protected	property	The lock backend.
ImageStyleDownloadController::$logger	protected	property	A logger instance.
ImageStyleDownloadController::create	public static	function	Instantiates a new instance of this class. Overrides FileDownloadController::create
ImageStyleDownloadController::deliver	public	function	Generates a derivative, given a style and image path.
ImageStyleDownloadController::__construct	public	function	Constructs a ImageStyleDownloadController object. Overrides FileDownloadController::__construct
LinkGeneratorTrait::$linkGenerator	protected	property	The link generator.	1
LinkGeneratorTrait::getLinkGenerator Deprecated	protected	function	Returns the link generator.
LinkGeneratorTrait::l Deprecated	protected	function	Renders a link to a route given a route name and its parameters.
LinkGeneratorTrait::setLinkGenerator Deprecated	public	function	Sets the link generator service.
LoggerChannelTrait::$loggerFactory	protected	property	The logger channel factory service.
LoggerChannelTrait::getLogger	protected	function	Gets the logger for a specific channel.
LoggerChannelTrait::setLoggerFactory	public	function	Injects the logger channel factory.
MessengerTrait::$messenger	protected	property	The messenger.	29
MessengerTrait::messenger	public	function	Gets the messenger.	29
MessengerTrait::setMessenger	public	function	Sets the messenger.
RedirectDestinationTrait::$redirectDestination	protected	property	The redirect destination service.	1
RedirectDestinationTrait::getDestinationArray	protected	function	Prepares a 'destination' URL query parameter for use with \Drupal\Core\Url.
RedirectDestinationTrait::getRedirectDestination	protected	function	Returns the redirect destination service.
RedirectDestinationTrait::setRedirectDestination	public	function	Sets the redirect destination service.
StringTranslationTrait::$stringTranslation	protected	property	The string translation service.	1
StringTranslationTrait::formatPlural	protected	function	Formats a string containing a count of items.
StringTranslationTrait::getNumberOfPlurals	protected	function	Returns the number of plurals supported by a given language.
StringTranslationTrait::getStringTranslation	protected	function	Gets the string translation service.
StringTranslationTrait::setStringTranslation	public	function	Sets the string translation service to use.	2
StringTranslationTrait::t	protected	function	Translates a string to the current language or to a given language.
UrlGeneratorTrait::$urlGenerator	protected	property	The url generator.
UrlGeneratorTrait::getUrlGenerator Deprecated	protected	function	Returns the URL generator service.
UrlGeneratorTrait::setUrlGenerator Deprecated	public	function	Sets the URL generator service.
UrlGeneratorTrait::url Deprecated	protected	function	Generates a URL or path for a specific route based on the given parameters.

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class ImageStyleDownloadController in Drupal 8

Hierarchy

File

Namespace

Members

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