    public function saveConfig() { 
        if (!empty($this->params['aggregate']) || !empty($this->params['pull_rss'])) {
            if ($this->params['order'] == 'rank ASC') {
                expValidator::failAndReturnToForm(gt('User defined ranking is not allowed when aggregating or pull RSS data feeds.'), $this->params);
            }
        }
        
        parent::saveConfig();
    }