e.dataTransfer is undefined

Question

I have a problem with my drag and drop item, when i drag got an error: "e.dataTransfer is undefined"

drag function

dragstart: function(e) {
    e.dataTransfer.effectAllowed = 'move';
    e.dataTransfer.dropEffect = 'move';
    e.dataTransfer.setData('application/json', index);
    element.addClass('dragging');
}

Someone know where is the problem?

Answer 1

Add dataTransfer prop explicitly:

e.dataTransfer = e.originalEvent.dataTransfer;

Answer 2

In jquery you have to use it like this, it will work:

e.originalEvent.dataTransfer.dropEffect = 'move';