Remove gzip encoding in Zend

Question

Lots of questions here from people trying to implement gzip encoding in Zend - I need to do the opposite!

I have a controller which extends the standard Zend_Controller_Action. My downloadAction has a PDF file as it's response body. That works well, except that the downloaded file isn't correctly recognised by the client browsers.

The downloaded file is identified as a 'Zip Archive' by the browser download. When saved and double-clicked it opens correctly as a PDF. The response header shows Content-Encoding:gzip, so I figure that's likely the culprit.

The core of my action is:

$this->_helper->layout()->disableLayout();
$this->_helper->viewRenderer->setNoRender(true);

if ($fd = fopen($pdfpath.$pdf->Filename,'r')) 
    {
        header('Content-Type: application/octet-stream');
        header('Content-Disposition: attachment; filename="summary.PDF"');
        while(!feof($fd)) 
        {
           $buffer = fread($fd, 2048);
           echo $buffer;
        }
        fclose($fd);
    }

There is some other code before this piece, but it does nothing more exciting than populate the variables.

How would I go about disabling the Content-Encoding:gzip header for just this response, or if that's the wrong end of the stick (it would be good to use compression, but not at the expense of user experience), how do I get the client to correctly identify the downloaded file once the compression has been reversed?

How is the content being gzipped in the first place? Do you have something server-side like mod_deflate that is compressing all of your pages? — Tim Fountain, Apr 28 '12 at 15:53
I don't think the gzip is the problem, but the content-type should be `application/pdf` like in b.b3rn4rd's post below. If you serve it as octet-stream, it doesn't know what type of file it is. If the gzip is done by a server module like Tim said, you will have to tweak the server config to disable it in some cases, which is outside the scope of php. — drew010, Apr 28 '12 at 17:10
I'm not sure exactly where the gzipping is happening - there's nothing specified at the server level, and if I download direct from the server (outside of PHP/Zend) it works fine. It's somewhere in Zend's handling of the response. With gzip encoding, Firefox and Chrome both fail to download. Opera works though. b.b3rn4rd's answer has solved it for me. It was both the gzip and the content-type causing me problems. — Grokling, Apr 28 '12 at 22:48

b.b3rn4rd · Accepted Answer · 2012-04-28T08:08:01.073

I would recommend to use framework's Zend_Controller_Response_Http instead of header() function, usually I specify "default" headers with gzip compression etc. in my Bootstrap for all responses, and override them in actions for some special reasons:

public function indexAction()
{
      $frontContoller = $this->getFrontController(); 
      $this->_helper->layout()->disableLayout();
      $this->_helper->viewRenderer->setNoRender(true);
      $response = new Zend_Controller_Response_Http();
      $response
        ->setHeader('Content-Type', 'application/pdf')
        ->setHeader('Content-Disposition', 'attachment; filename=summary.pdf')
        ->setHeader('Expires', ''.gmdate('D, d M Y H:i:s', strtotime('31.08.1986')) . ' GMT', true)
        ->setHeader('Cache-Control', 'no-cache')
        ->setHeader('Pragma', 'no-cache', true);

      $response->setBody(file_get_contents('/full/path/to/summary.pdf'));
      $frontContoller->setResponse($response);

}

Remove gzip encoding in Zend

1 Answers1