/**
  * Save material assignment
  */
 public function saveItemAssignment()
 {
     global $ilCtrl;
     $this->checkPermission("write");
     include_once './Modules/ItemGroup/classes/class.ilItemGroupItems.php';
     $item_group_items = new ilItemGroupItems($this->object->getRefId());
     $items = is_array($_POST['items']) ? $_POST['items'] : array();
     $items = ilUtil::stripSlashesArray($items);
     $item_group_items->setItems($items);
     $item_group_items->update();
     ilUtil::sendSuccess($this->lng->txt('msg_obj_modified'), true);
     $ilCtrl->redirect($this, "listMaterials");
 }