JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://dev.sencha.com/deploy/ext-4.0.2a/resources/css/ext-all.css">

JavaScript

Ext.create('Ext.panel.Panel', {
        width: 500,
        height: 400,
        title: 'Border Layout',
        layout: 'border',
        items: [{
            title: 'South Region is resizable',
            region: 'south',     // position for region
            xtype: 'panel',
            height: 100,
            split: true,         // enable resizing
            margins: '0 5 5 5'
        },{
            // xtype: 'panel' implied by default
            title: 'West Region is collapsible',
            region:'west',
            xtype: 'panel',
            margins: '5 0 0 5',
            width: 200,
            collapsible: true,   // make collapsible
            id: 'west-region-container',
            layout: 'fit'
        },{
            title: 'Center Region',
            region: 'center',     // center region is required, no width/height specified
            xtype: 'panel',
            layout: 'fit',
            margins: '5 5 0 0'
        }],
        renderTo: Ext.getBody()
    });
Ext.getCmp('west-region-container').setLoading('dgdgh');