Ext JS tree panel example

<!DOCTYPE html>
<html>

  <head>
    <link data-require="extjs@4.2.0" data-semver="4.2.0" rel="stylesheet" href="http://cdn.sencha.io/ext-4.2.0-gpl/resources/css/ext-all.css" />
    <script data-require="extjs@4.2.0" data-semver="4.2.0" src="http://cdn.sencha.io/ext-4.2.0-gpl/ext-all.js"></script>
    <script src="script.js"></script>
  </head>

  <body>
  </body>

</html>

Ext.onReady(function() {
    Ext.create('Ext.tree.Panel', {
        store: Ext.create('Ext.data.TreeStore', {
            root: {
                text: 'Root Folder',
                expanded: true,
                children: [
                    {text: 'Folder 1', children: [
                        {text: 'Item 1', leaf: true}
                    ]},
                    {text: 'Folder 2', expanded: true, children: [
                        {text: 'Item 2', leaf: true},
                        {text: 'Item 3', leaf: true}
                    ]},
                    {text: 'Folder 3', children: []}
                ]
            }
        }),
        renderTo: Ext.getBody()
    });
});