html download tag

Question

The basic problem is this: I have a link to an image file. The desired behavior when I click on the link is to get the download dialog which would allow me to launch an associated image editor. This doesn't happen because the image file is rendered by the browser.

Is there any html magic which I can use to force the browser to offer a download dialog when the user clicks on a link?

Any help or pointers would be much appreciated.

Answer 1

Not possible with just HTML however you can force the file to be downloaded via modifying headers with a server side language such as PHP.

// grab the requested file's name
$file_name = $_GET['file'];

// make sure it's a file before doing anything!
if(is_file($file_name))
{

    /*
        Do any processing you'd like here:
        1.  Increment a counter
        2.  Do something with the DB
        3.  Check user permissions
        4.  Anything you want!
    */

    // required for IE
    if(ini_get('zlib.output_compression')) { ini_set('zlib.output_compression', 'Off'); }

    // get the file mime type using the file extension
    switch(strtolower(substr(strrchr($file_name,'.'),1)))
    {
        case 'pdf': $mime = 'application/pdf'; break;
        case 'zip': $mime = 'application/zip'; break;
        case 'jpeg':
        case 'jpg': $mime = 'image/jpg'; break;
        default: $mime = 'application/force-download';
    }
    header('Pragma: public');   // required
    header('Expires: 0');       // no cache
    header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
    header('Last-Modified: '.gmdate ('D, d M Y H:i:s', filemtime ($file_name)).' GMT');
    header('Cache-Control: private',false);
    header('Content-Type: '.$mime);
    header('Content-Disposition: attachment; filename="'.basename($file_name).'"');
    header('Content-Transfer-Encoding: binary');
    header('Content-Length: '.filesize($file_name));    // provide file size
    header('Connection: close');
    readfile($file_name);       // push it out
    exit();

}

Answer 2

if you want to show up download dialog, you need to put special headers to your image

in PHP it will be:

header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename=image.jpg');
header('Content-Transfer-Encoding: binary');

Answer 3

Another solution would be to add this to an htaccess file in the folder with your images:

AddType application/octet-stream .jpg