how to print preview first before download the file while using dompdf library.

Question

I am using dompdf library (0.8.2) for print preview and print invoices. Below code doesnot show the print preview but download file immediately. I want to see print preview first before download the file. I tried to array("Attachment"=>0) also, but not worked.

   $dompdf = new Pdf();
   $file_name = 'Invoice-'.$row["order_no"].'.pdf';
   $dompdf->loadHtml($output);

   //$dompdf->setPaper('A4', 'landscape');

   $dompdf->render();
   $dompdf->stream($file_name,array("Attachment"=>false));
   //exit(0);
   }
   ?>