protected function extractUrlVariables($url){
        $variables = array();
        $pattern = "/(\\".static::$_URL_VAR_CHARACTER.".*?[^\\/]*)/";
        if (preg_match($pattern,$url,$matches)){
            array_shift($matches);
            foreach($matches as $match){
                $variables[] = $match[0];
            }
        }
        return $variables;
    }