Backbone.js drop event doesn't work

Question

I have problem with drop event.

In my template I have a div which is a drop area. When I drop a file I want disable reload site and show photo.

prevenDefault() doesn't work, my site is reloaded and I can see only photo which was uploaded

<div class="text-center js-upload">
</div>

JavaScript

ui: {
   upload: '.js-upload'
},
events: {
  'drop @ui.upload': 'onDrop'
},
onDrop: function (event) {
  event.preventDefault();
},

Answer 1

To solve this problem, I used solution from
Why preventDefault does not work?

$('#imgDropzone').on("dragenter dragstart dragend dragleave dragover drag drop", function (e) {
    e.preventDefault();
});

In my example, I similarly added preventDefault for all drag&drop events.