Prado\Web\UI\ActiveControls\TActiveFileUpload::addAttributesToRender PHP Method

    public function addAttributesToRender($writer)
    {
        parent::addAttributesToRender($writer);
        $writer->addAttribute('id', $this->getClientID());
        $this->getPage()->getClientScript()->registerPradoScript('activefileupload');
        $this->getActiveControl()->registerCallbackClientScript($this->getClientClassName(), $this->getClientOptions());
    }