https://github.com/blueimp/jQuery-File-Upload/wiki/Options#callback-options
https://github.com/blueimp/jQuery-File-Upload/wiki/Options#processing-callback-options
Such an approach has the following problems can cause jquery.fileupload-process.js the options [add] can not be triggered
https://github.com/blueimp/jQuery-File-Upload/blob/master/js/jquery.fileupload-process.js#L54
$(function () { $('#fileupload').fileupload({ dataType: 'json', add: function (e, data) { data.context = $('<button/>').text('Upload') .appendTo(document.body) .click(function () { data.context = $('<p/>').text('Uploading...').replaceAll($(this)); data.submit(); }); }, done: function (e, data) { data.context.text('Upload finished.'); } }); });