Prado\Web\UI\WebControls\TTabPanel::onPreRender PHP Method

    public function onPreRender($param)
    {
        parent::onPreRender($param);
        $this->getActiveView();
        // determine the active view
        $this->registerStyleSheet();
        $page = $this->getPage();
        $page->registerRequiresPostData($this);
        $page->registerRequiresPostData($this->getClientID() . "_1");
    }