function hook_file_download

Control access to private file downloads and specify HTTP headers.

This hook allows modules enforce permissions on file downloads when the private file download method is selected. Modules can also provide headers to specify information like the file's name or MIME type.

Parameters

$uri: The URI of the file.

Return value

If the user does not have permission to access the file, return -1. If the: user has permission, return an array with the appropriate headers. If the file is not controlled by the current module, the return value should be NULL.

See also

file_download()

Related topics

File

core/modules/system/system.api.php, line 2341

Hooks provided by Backdrop core and the System module.

Code

function hook_file_download($uri) {
  // Check if the file is controlled by the current module.
  if (!file_prepare_directory($uri)) {
    $uri = FALSE;
  }
  if (strpos(file_uri_target($uri), config_get('system.core', 'user_picture_path') . '/picture-') === 0) {
    if (!user_access('access user profiles')) {
      // Access to the file is denied.
      return -1;
    }
    else {
      $info = image_get_info($uri);
      return array('Content-Type' => $info['mime_type']);
    }
  }
}