Upload Progress — Request

I needed a handle on the upload progress for yet another project of mine.

What I found out is that you can poll the request's connection._bytesDispatched property.

For example:

r = request.post url: "http://foo.com", body: fileAsBuffer
setInterval (-> console.log "Uploaded: #{r.req.connection._bytesDispatched}"), 250

Note: If you were piping to r, poll r.req.connection.socket._bytesDispatched instead.

Someone has created a nice module to accomplish this that has been running in the production stack for transloadit (so it is dependable and well maintained). You can find it here:

https://github.com/felixge/node-formidable

Code should look like:

var formidable = require('formidable'),
    http = require('http'),

    util = require('util');

http.createServer(function(req, res) {
  if (req.url == '/upload' && req.method.toLowerCase() == 'post') {
    // parse a file upload
    var form = new formidable.IncomingForm();
    form.parse(req, function(err, fields, files) {
      res.writeHead(200, {'content-type': 'text/plain'});
      res.write('received upload:\n\n');
      res.end(util.inspect({fields: fields, files: files}));
    });
    return;
  }

  // show a file upload form
  res.writeHead(200, {'content-type': 'text/html'});
  res.end(
    '<form action="/upload" enctype="multipart/form-data" method="post">'+
    '<input type="text" name="title"><br>'+
    '<input type="file" name="upload" multiple="multiple"><br>'+
    '<input type="submit" value="Upload">'+
    '</form>'
  );
}).listen(80);

You could then push status to a client using Socket.io

Interesting Note: This was one of the problems that led to Node's creation. In this video Ryan talks about how node was started trying to find the best way of notifying a user, real time, about the status of file upload over the web...anyway I digress, but the video is worth a watch if you are interested in Node's history

Try this approach:

var file = fs.createWriteStream("largefile.jpg");
var totalbytes = request.headers['content-length'];
var donesofar = 0;

request.pipe(file);
request.on('data', function(chunk){
    donesofar += chunk.length;
    var progress = (donesofar / totalbytes) * 100;
    response.write(parseInt(progress, 10) + "%\n");

});