public function ImageStyleDownloadController::deliver in WebP 8

Generates a derivative, given a style and image path.

After generating an image, transfer it to the requesting agent.

Parameters

\Symfony\Component\HttpFoundation\Request $request: The request object.

string $scheme: The file scheme, defaults to 'private'.

\Drupal\image\ImageStyleInterface $image_style: The image style to deliver.

Return value

\Symfony\Component\HttpFoundation\BinaryFileResponse|\Symfony\Component\HttpFoundation\Response The transferred file as response or some error response.

Throws

\Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException Thrown when the user does not have access to the file.

\Symfony\Component\HttpKernel\Exception\ServiceUnavailableHttpException Thrown when the file is still being generated.

File

src/Controller/ImageStyleDownloadController.php, line 105

Class

ImageStyleDownloadController

Defines a controller to serve image styles.

Namespace

Drupal\webp\Controller

Code

public function deliver(Request $request, $scheme, ImageStyleInterface $image_style) {
  $target = $request->query
    ->get('file');
  $image_uri = $scheme . '://' . $target;
  if ($webp_wanted = preg_match('/\\.webp$/', $image_uri)) {
    $path_info = pathinfo($image_uri);
    $possible_image_uris = [
      // 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['dirname'] . DIRECTORY_SEPARATOR . $path_info['filename'],
    ];

    // Try out the different possible sources for a webp image.
    $extensions = [
      '.jpg',
      '.jpeg',
      '.png',
    ];
    foreach ($extensions as $extension) {
      $possible_image_uris[] = str_replace('.webp', mb_strtoupper($extension), $image_uri);
      $possible_image_uris[] = str_replace('.webp', $extension, $image_uri);
    }
    foreach ($possible_image_uris as $possible_image_uri) {
      if (file_exists($possible_image_uri)) {
        $image_uri = $possible_image_uri;
        break;
      }
    }
  }

  // Don't try to generate file if source is missing.
  if (!file_exists($image_uri)) {
    $this->logger
      ->notice('Source image at %source_image_path not found while trying to generate derivative image.', [
      '%source_image_path' => $image_uri,
    ]);
    return new Response($this
      ->t('Error generating image, missing source file.'), 404);
  }

  // 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 &= $request->query
      ->get(IMAGE_DERIVATIVE_TOKEN) === $image_style
      ->getPathToken($image_uri);

    // ImageAPI Optimize case: generator searches for a WEBP, but image style
    // returns a non-WEBP (!= tokens). Sanity checks that image_style returns a token.
    if (!$valid && $image_style
      ->getDerivativeExtension(pathinfo($image_uri)['extension']) != "webp") {
      $valid = $image_style
        ->getPathToken($image_uri) ? true : false;
    }
  }
  if (!$valid) {
    throw new AccessDeniedHttpException();
  }
  $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 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, $this
        ->t('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);
    if ($webp_wanted && ($webp = $this->webp
      ->createWebpCopy($image
      ->getSource())) && in_array('image/webp', $request
      ->getAcceptableContentTypes())) {
      return $this
        ->webpResponse($webp, $headers, $scheme);
    }
    else {
      return $this
        ->response($image, $headers, $scheme);
    }
  }
  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);
  }
}