public function getSubject()
    {
        if (null === $this->subject && $this->request) {
            $id = $this->request->get($this->getIdParameter());
            if (null === $id || !preg_match('#^[0-9A-Za-z/\-_]+$#', $id)) {
                $this->subject = false;
            } else {
                if (!UUIDHelper::isUUID($id)) {
                    $id = PathHelper::absolutizePath($id, '/');
                }
                $this->subject = $this->getObject($id);
            }
        }

        return $this->subject;
    }