Check it out: PURE AJAX file uploads :D

[select]

in your client side js code use the js file api (this is for one file, but multi file upload can be done too)

$('#datafile-uploadfield').change(function() {
    var upload_element = $(this)[0];
    var file = upload_element.files[0];
    if (file) {
      var reader = new FileReader();
      reader.readAsDataURL(file); //, "UTF-8");//TODO what encoding should be parsed???
      reader.onload = (function(theFile) {
        return function(evt) {
          $.ajax({
            url: '{{=URL("datafile_create")}}',
            data: {
              data: evt.target.result,
              name: theFile.name
            },
            type: 'POST',
            dataType: 'json',
            success: function(data) {
              addDatafile(data);
            }
          });
        };
      })(file);
      reader.onerror = function(evt) {
        alert(":( oh noo, we could not read your file");
      };
      //++counter;
    }
  });

in you controller

def datafile_create():
    splitcontents = request.vars.data.split(',')
    import base64
    file_content = base64.b64decode(splitcontents[1])
    # create file like object
    import StringIO
    filelike_obj = StringIO.StringIO(file_content)
    db_store = db.datafiles.file.store(filelike_obj, request.vars.name)
    record_id = db.datafiles.insert(file=db_store)

in you db.py

db.define_table('datafiles',
 Field('file', 'upload', requires=IS_NOT_EMPTY()),
 )

== PURE AWESOMENESS

[Niphlod]

why the base64 ? I want my files submitted as binaries, if possibile.....

[select]

readAsBinaryString and readAsArrayBuffer and readAsText

did not work, i just tested, but if you have a hint on how to make them work I would be very interested

[Niphlod]

it's not that I don't like the use of native js api, but if the tradeoff is transmitting as base64 that's not an implementation I want to use (given that there are plenty of "drop-loaders" out there).
Base64 the contents means wasting a net 33% of bandwith.

[select]

so what do these drop loaders do to make pure ajax file uploads, i was not aware of that o_O

[select]

so i basically missed what is going on right now because I did not looked at the problem for half a year 

http://caniuse.com/xhr2

xhr2 is supported by almost all browsers and xhr2 supports sending files :D

implementations are here 

http://stackoverflow.com/a/10811427/1436151

http://stackoverflow.com/questions/4856917/jquery-upload-progress-and-ajax-file-upload/4943774#4943774