/**
  * Save file usages
  */
 static function saveFileUsage($a_page, $a_domdoc, $a_old_nr = 0)
 {
     $file_ids = self::collectFileItems($a_page, $a_domdoc);
     include_once "./Modules/File/classes/class.ilObjFile.php";
     ilObjFile::_deleteAllUsages($a_page->getParentType() . ":pg", $a_page->getId(), $a_old_nr, $a_page->getLanguage());
     foreach ($file_ids as $file_id) {
         ilObjFile::_saveUsage($file_id, $a_page->getParentType() . ":pg", $a_page->getId(), $a_old_nr, $a_page->getLanguage());
     }
 }
 /**
  * save file usages
  */
 function saveFileUsage($a_xml = "", $a_old_nr = 0)
 {
     $file_ids = $this->collectFileItems($a_xml, $a_old_nr);
     include_once "./Modules/File/classes/class.ilObjFile.php";
     ilObjFile::_deleteAllUsages($this->getParentType() . ":pg", $this->getId(), $a_old_nr);
     foreach ($file_ids as $file_id) {
         ilObjFile::_saveUsage($file_id, $this->getParentType() . ":pg", $this->getId(), $a_old_nr);
     }
 }