drag and drop with backbone

drag drop backbone jquery UI

$('#overlay-objet img').droppable({
    tolerance: 'pointer',
    drop: _.bind(function(event, ui) {
      object     = $(event.target);
      if (object.attr("data-val") != undefined){
        objectDrag = object.attr('data-val').toString();
        objectDrop = $(ui.draggable).attr('data-val').toString();
        //$(ui.draggable).removeClass('objet-drag').addClass('objet-hover');
        object.addClass('hidden');
        $('#'+object.attr('data-toggle')).removeClass('hidden');
        this.dragDropEvent(objectDrag + objectDrop);
      }
    }, this),
    over: _.bind(function(event,ui){
      object = $(event.target);
      object.addClass('hidden');
      $('#'+object.attr('data-toggle')).removeClass('hidden');
    }, this),
    out: _.bind(function(event,ui){
      object = $(event.target);
      object.removeClass('hidden');
      $('#'+object.attr('data-toggle')).addClass('hidden');
    }, this) // Edit mercredi soir ajouter ,this dans chaque callback
  });
      $('img.big-objet').draggable({
        helper: "clone"
});