public function getRouteURL()
    {
        if (empty($this->routeUrl)) {
            $param = trim(Server::get('REQUEST_URI'), '/');

            // strip base directory from request url
            $base_dir = $this->getBaseDir();
            $param = substr($param, strlen($base_dir));

            // Strip query string (?a=b) from Request Url
            $path = trim(explode('?', $param)[0], '/');
            $this->routeUrl = strtolower($path);

            if (empty($this->routeUrl)) {
                $this->routeUrl = '/';
            }
        }

        return $this->routeUrl;
    }