/**
  * Delete group
  *
  * @param void
  * @return null
  */
 function delete()
 {
     if (!can_manage_security(logged_user())) {
         flash_error(lang('no access permissions'));
         ajx_current("empty");
         return;
     }
     // if
     $group = Groups::findById(get_id());
     if (!$group instanceof Group) {
         flash_error(lang('group dnx'));
         ajx_current("empty");
         return;
     }
     // if
     try {
         DB::beginWork();
         $group->delete();
         ApplicationLogs::createLog($group, null, ApplicationLogs::ACTION_DELETE);
         DB::commit();
         flash_success(lang('success delete group', $group->getName()));
         ajx_current("reload");
     } catch (Exception $e) {
         DB::rollback();
         flash_error(lang('error delete group'));
         ajx_current("empty");
     }
     // try
 }
 function getUserOrGroup()
 {
     if ($this->getUserId() < Group::CONST_MINIMUM_GROUP_ID) {
         // it's a user
         if (!$this->user_or_group instanceof User) {
             $this->user_or_group = Users::findById($this->getUserId());
         }
     } else {
         // it's a group
         if (!$this->user_or_group instanceof Group) {
             $this->user_or_group = Groups::findById($this->getUserId());
         }
     }
     return $this->user_or_group;
 }