force download

    $file = $document->getFileName();
        $file_url = "uploads/".$file;

        header("Pragma: public");
        header("Expires: 0");
        header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
        header("Cache-control: public");
        header("Content-Description: File Transfer");
        header('Content-Disposition: attachment; filename="'.basename($file).'"');
        header('Content-Type: application/octet-stream');
        header("Content-Length: " . filesize($file_url));


        $document->registerDownload();
        readfile($file_url);