public function getActLanguageId()
    {
        if (($sValue = $this->getViewConfigParam('lang')) === null) {
            $iLang = $this->getConfig()->getRequestParameter('lang');
            $sValue = ($iLang !== null) ? $iLang : \OxidEsales\Eshop\Core\Registry::getLang()->getBaseLanguage();
            $this->setViewConfigParam('lang', $sValue);
        }

        return $sValue;
    }