JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://cdn.kendostatic.com/2011.3.1129/styles/kendo.common.min.css">
<link rel="stylesheet" href="http://cdn.kendostatic.com/2011.3.1129/styles/kendo.default.min.css">
<script src="http://cdn.kendostatic.com/2011.3.1129/js/kendo.all.min.js"></script>
<ul id="tree">
    <li id="item1">Item 1
        <ul>
            <li></li>
        </ul>        
    </li>
    <li>Item 2</li>
    <li>Item 3</li>
</ul>

JavaScript

$(function() {
    function appendNodes(node, subNodes, treeView) {
        $.each(subNodes, function() {
            $(node).find('.k-icon:first').removeClass('k-loading');
            treeView.append({
                text: this.Text
            }, $(node));
            if (this.HasChilds) {
                treeView.append({
                    text: ""
                }, $(node).find('.k-group:first').children('li:last'));
            }
        });
    }

    $('#tree').kendoTreeView({
        expand: function(e) {
            var treeView = $('#tree').data('kendoTreeView');
            if ($(e.node).find('ul:first').find('li').length == 1 && $(e.node).find('ul:first').find('li:first').find('.k-in').text() == "") {
                $(e.node).find('.k-icon:first').addClass('k-loading');
                $(e.node).find('ul:first').html("");
                if ($(e.node).is('#item1')) {
                    var nodes = [{
                        Text: "Item 1.1",
                        HasChilds: true},
                    {
                        Text: "Item 1.2",
                        HasChilds: true},
                    {
                        Text: "Item 1.3",
                        HasChilds: false},
                    {
                        Text: "Item 1.4",
                        HasChilds: false},
                    {
                        Text: "Item 1.5",
                        HasChilds: false}];
                    appendNodes(e.node, nodes, treeView);
                } else if ($(e.node).find('.k-in:first').text() == "Item 1.1") {
                    var nodes = [{
                        Text: "Item 1.1.1",
                        HasChilds: true}];
                    appendNodes(e.node, nodes, treeView);
                } else if ($(e.node).find('.k-in:first').text() == "Item 1.1.1") {
                    var nodes = [{Text: "Item 1.1.1.1", HasChilds: true}];
                    appendNodes(e.node, nodes, treeView);
               ...