I Don\'t understand that... call its always undefined
Create the mock file:
var mockFile = { name: \"Filename\", size: 12345 };
I was having hard time with this also. This one as a starting point would have helped even more:
Dropzone.autoDiscover = false; // otherwise will be initialized twice
var myDropzoneOptions = {
maxFilesize: 5,
addRemoveLinks: true,
clickable: true
};
var myDropzone = new Dropzone('#myDropzoneElement', myDropzoneOptions);
var mockFile = { name: "Existing file!", size: 12345 };
myDropzone.options.addedfile.call(myDropzone, mockFile);
myDropzone.options.thumbnail.call(myDropzone, mockFile, "http://url-to-thumb-goes-here");