/**
* Validate data.
*
* This ensures that key file is provided if URL is provided.
*
* @param string $data
* @return mixed True on success, else error message.
*/
public function validate($data)
{
$result = parent::validate($data);
if ($result !== true) {
return $result;
}
$usercontext = context_user::instance($USER->id);
$url = get_config('filter_cloudfront_signurl', 'distributionurl');
$fs = get_file_storage();
if ($url != '' && empty($data)) {
return get_string('errornoprivatekey', 'filter_cloudfront_signurl');
}
return true;
}
