Question

I am using PHP’s ZipArchive class to create a zip file containing photos and then serve it up to the browser for download. Here is my code:

/**
 * Grabs the order, packages the files, and serves them up for download.
 *
 * @param string $intEntryID 
 * @return void
 * @author Jesse Bunch
 */
public static function download_order_by_entry_id($intUniqueID) {

    $objCustomer = PhotoCustomer::get_customer_by_unique_id($intUniqueID);

    if ($objCustomer):

        if (!class_exists('ZipArchive')):
            trigger_error('ZipArchive Class does not exist', E_USER_ERROR);
        endif;

        $objZip = new ZipArchive();
        $strZipFilename = sprintf('%s/application/tmp/%s-%s.zip', $_SERVER['DOCUMENT_ROOT'], $objCustomer->getEntryID(), time());

        if ($objZip->open($strZipFilename, ZIPARCHIVE::CREATE) !== TRUE):

            trigger_error('Unable to create zip archive', E_USER_ERROR);

        endif;          

        foreach($objCustomer->arrPhotosRequested as $objPhoto):

            $filename = PhotoCart::replace_ee_file_dir_in_string($objPhoto->strHighRes);
            $objZip->addFile($filename,sprintf('/press_photos/%s-%s', $objPhoto->getEntryID(), basename($filename)));

        endforeach;

        $objZip->close();

        header('Last-Modified: '.gmdate('D, d M Y H:i:s', filemtime($strZipFilename)).' GMT',  TRUE, 200);
        header('Cache-Control: no-cache', TRUE);
        header('Pragma: Public', TRUE);
        header('Expires: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT', TRUE);
        header('Content-Length: '.filesize($strZipFilename), TRUE);
        header('Content-disposition: attachment; filename=press_photos.zip', TRUE);

        header('Content-Type: application/octet-stream', TRUE);

        ob_start();
        readfile($strZipFilename);
        ob_end_flush();
        exit;

    else:

        trigger_error('Invalid Customer', E_USER_ERROR);

    endif;

}

This code works really well with all browsers but IE. In IE, the file downloads correctly, but the zip archive is empty. When trying to extract the files, Windows tells me that the zip archive is corrupt. Has anyone had this issue before?

Edit Update: After suggestion from @profitphp, I changed my headers to this:

header("Cache-Control: public");
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-type: application/zip");
header("Content-Disposition: attachment; filename=\"pressphotos.zip\"");
//header("Content-Transfer-Encoding: binary");
header("Content-length: " . filesize($strZipFilename));

Also, here is a screenshot of the error in Windows after opening with Firefox:

This error occurs in both IE and Firefox on Windows. It works fine in Mac. Also, in Windows, the filesize appears to be correct:

Edit #2 This issue is sovled. See my answer below.

Answer 1

Ok, after much strife, I figured out the problem. The issue comes from the following line of code:

$objZip->addFile($filename,sprintf('/press_photos/%s-%s', $objPhoto->getEntryID(), basename($filename)));

For some reason, the /press_photos/ part of that path for the local (internal) file name inside the zip archive was causing Windows to think the zip file was corrupt. After modifying the line to look like what is below, Windows opened the zip files correctly. Phew.

$objZip->addFile($filename,sprintf('%s-%s', $objPhoto->getEntryID(), basename($filename)));