save_order_after_sort.js

var list = $(".type_data_articles ul.select2-selection__rendered"),
    list_li = $(".type_data_articles ul.select2-selection__rendered li.select2-selection__choice"),
    list_b = $(".type_data_articles ul.select2-selection__rendered b"),
    select2 = $(".type_data_articles .select2_from_array"),
    select2Backup = $(".type_data_articles .select2_from_array option");

list.sortable({
  containment: 'parent',
  update: function() {
      var select2val = [];
      $(".type_data_articles ul.select2-selection__rendered li.select2-selection__choice").each(function() {
        select2val.push( $(this).children('b').data('id'));
      });

      select2.empty().trigger('change');
      for (var i = 0; i < select2val.length; i++) {
        select2Backup.each(function(index, elem){
          if ($(this).attr('value') == select2val[i]) {
            var option = new Option($(this).text(), $(this).attr('value'), true, true);
            option.setAttribute('data-category', $(this).attr('data-category'));
            option.title = $(this).attr('title');
            select2.append(option).trigger('change');
            return false;
          }
        });
      }
      select2Backup.each(function(index, elem){
        if (select2val.indexOf( +$(this).attr('value') ) == -1) {
          var option = new Option($(this).text(), $(this).attr('value'), false, false);
          option.title = $(this).attr('title');
          option.setAttribute('data-category', $(this).data('category'));
          select2.append(option).trigger('change');
        }
      });

  }
});