summernote style dropdown not work code example

Example: summernote dropdown plugin

var emojiBtn = function (context) {

    var ui = $.summernote.ui;
    var list = $('#elements-list').val();

    var button = ui.buttonGroup([
              ui.button({
                className: 'dropdown-toggle',
                contents: '<span class="fa fa-smile-o"></span> <span class="caret"></span>',
                tooltip: "Insert Greetings",
                data: {
                  toggle: 'dropdown'
                }
              }),
              ui.dropdown({
                className: 'drop-default summernote-list',
                contents: "<ul>"+list+"</ul>",
                callback: function ($dropdown) {
                    $dropdown.find('li').each(function () {
                      $(this).click(function() {
                        context.invoke("editor.insertText", $(this).html());
                      });
                    });
                }
              })
    ]);

    return button.render();
}