ajax - Jquery and HTML FormData returns "Uncaught TypeError: Illegal invocation"

Question

I'm using this script to upload my image files: http://jsfiddle.net/eHmSr/

$('.uploader input:file').on('change', function() {
  $this = $(this);

  $('.alert').remove();

  $.each($this[0].files, function(key, file) {
    $('.files').append('<li>' + file.name + '</li>');

    data = new FormData();
    data.append(file.name, file);

    $.ajax({
      url: $('.uploader').attr('action'),
      type: 'POST',
      dataType: 'json',
      data: data
    });
  });
});

But when I click in upload button, the JavaScript console returns this error:

Uncaught TypeError: Illegal invocation 

Can you help me?

Answer 1

jQuery processes the data attribute and converts the values into strings.

Adding processData: false to your options object fixes the error, but I'm not sure if it fixes the problem.

Demo: http://jsfiddle.net/eHmSr/1/