Need help sending a binary file

[Blake McBride]

Greetings,

I have a binary (zip) file I would like to send to a browser.  The browser already knows the file name.  I would like the browser to provide a save-as dialog defaulting to the name it already knows.  I have everything working except that the file being sent and the file received don't end up the same length.  The resulting file is a lot larger (binary encoding?) and is corrupt.  Here is what I am using on the node/express side:

 var options = {
// root: __dirname + '/' + downloadPath + '/',
    dotfiles: 'deny',
    headers: {
      'x-timestamp': Date.now(),
      'x-sent': true
    }
 };

 fullZipPath = downloadPath + '/' + fileName;
 var absPath = path.resolve(fullZipPath);
 res.attachment(absPath);
 res.setHeader('Content-Disposition', 'attachment');
 res.set('Content-Type', 'application/octet-stream');
 res.sendFile(absPath, options, function (err) {
     if (err) {
        console.log(err);
        res.status(err.status).end();
     } else {
        console.log('Sent:', absPath);
     }
 });

Here is what I have on the browser side:

var downloadStream = function (filename, data) {
    var pom = document.createElement('a');
    pom.setAttribute('href', 'data:application/zip;charset=utf-8,' + encodeURIComponent(data));
    pom.setAttribute('download', filename);
    if (document.createEvent) {
        var event = document.createEvent('MouseEvents');
        event.initEvent('click', true, true);
        pom.dispatchEvent(event);
    } else {
        pom.click();
    }
}

I really appreciate the help.  I've been working on this for a whole day already.

Thanks.

Blake McBride

[Aaron Martone]

res.attachment(file), doesn't that set the Content-Dispo and Content-Type headers based on the file type? Can you try omitting those?

Also, can you ensure that the browser's request headers accept both application/zip and application/octet-stream?

Was the file uploaded by FTP? Did they by chance upload it as ASCII data rather than Binary in case automatic detection wasn't enabled?