function image_file_download

Implements hook_file_download().

Control the access to files underneath the styles directory.

File

core/modules/image/image.module, line 139

Code

function image_file_download($uri) {
  $path = StreamWrapperManager::getTarget($uri);
  // Private file access for image style derivatives.
  if (strpos($path, 'styles/') === 0) {
    $args = explode('/', $path);
    // Discard "styles", style name, and scheme from the path
    $args = array_slice($args, 3);
    // Then the remaining parts are the path to the image.
    $original_uri = StreamWrapperManager::getScheme($uri) . '://' . implode('/', $args);
    // Check that the file exists and is an image.
    $image = \Drupal::service('image.factory')->get($uri);
    if ($image->isValid()) {
      // Check the permissions of the original to grant access to this image.
      $headers = \Drupal::moduleHandler()->invokeAll('file_download', [
        $original_uri,
      ]);
      // Confirm there's at least one module granting access and none denying access.
      if (!empty($headers) && !in_array(-1, $headers)) {
        return [
          // Send headers describing the image's size, and MIME-type.
'Content-Type' => $image->getMimeType(),
          'Content-Length' => $image->getFileSize(),
        ];
      }
    }
    return -1;
  }
}