protected function LinkWithSearch($link) {
        // Whitelist to avoid side effects
        $params=array(
                    'q'=>(array)$this->request->getVar('q'),
                    'tag'=>$this->request->getVar('tag'),
                    'creator'=>$this->request->getVar('creator'),
                    'ParentID'=>$this->request->getVar('ParentID')
                );
        
        $link=Controller::join_links(
                                    $link,
                                    (array_filter(array_values($params)) ? '?'.http_build_query($params):null)
                                );
        
        $this->extend('updateLinkWithSearch', $link);
        return $link;
    }