public function process()
    {
        parent::process();

        $flydown = $this->getCompositeWidget('action_flydown');
        $selected_id = $flydown->value;

        if (isset($this->action_items_by_id[$selected_id])) {
            $this->selected = $this->action_items_by_id[$selected_id];

            if ($this->selected->widget !== null) {
                $this->selected->widget->process();
            }
        } else {
            $this->selected = null;
        }
    }