/**
  * Returns cache key (in non admin mode)
  *
  * @param string $sType   object type
  * @param int    $iLang   active language id
  * @param mixed  $iShopId active shop id
  * @param string $sParams additional seo params. optional (mostly used for db indexing)
  *
  * @return string
  */
 protected function _getCacheKey($sType, $iLang = null, $iShopId = null, $sParams = null)
 {
     $blAdmin = $this->isAdmin();
     if (!$blAdmin && $sType !== "oxarticle") {
         return $sType . (int) $iLang . (int) $iShopId . "seo";
     }
     // use cache in non admin mode
     if (self::$_sCacheKey === null) {
         self::$_sCacheKey = false;
         if (!$blAdmin && ($oView = $this->getConfig()->getActiveView())) {
             self::$_sCacheKey = md5($oView->getViewId()) . "seo";
         }
     }
     return self::$_sCacheKey;
 }