public function filter_uri(&$str)
{
if (!empty($str) && !empty($this->_permitted_uri_chars) && !preg_match('/^[' . $this->_permitted_uri_chars . ']+$/i' . (UTF8_ENABLED ? 'u' : ''), $str)) {
show_error('The URI you submitted has disallowed characters.', 400);
}
}