/**
  * Replaces the BlueSpiceSkin screen.less file with the one specified by the parameters
  * @global string $wgResourceModules
  * @param string $sFlexiskinId
  * @param int $bIsTemp
  * @return boolean true of replaced correctly, otherwise false
  */
 public function addCssFile($sFlexiskinId, $bIsTemp = false)
 {
     global $wgResourceModules;
     $oStatus = BsFileSystemHelper::ensureDataDirectory("flexiskin/" . $sFlexiskinId);
     if (!$oStatus->isGood()) {
         return false;
     }
     $sFilePath = BsFileSystemHelper::getDataPath("flexiskin/" . $sFlexiskinId);
     $sFilePath .= "/screen" . ($bIsTemp ? '.tmp' : '') . ".less";
     if (!isset($wgResourceModules['skins.bluespiceskin']) || !isset($wgResourceModules['skins.bluespiceskin']['styles'])) {
         return false;
     }
     foreach ($wgResourceModules['skins.bluespiceskin']['styles'] as $iIndex => $sStylePath) {
         //check if element ends with "screen.less"
         if (strpos($sStylePath, "screen.less", strlen($sStylePath) - strlen("screen.less")) === false) {
             continue;
         }
         $wgResourceModules['skins.bluespiceskin']['styles'][$iIndex] = ".." . $sFilePath;
         return true;
     }
     return false;
 }