JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://dev.sencha.com/deploy/ext-4.0.0/resources/css/ext-all.css">

JavaScript

Ext.define('ItemTemplateModel', {
	extend: 'Ext.data.Model',
    fields: [
		{ name: 'id', type: 'int' },
		{ name: 'imageUri', type: 'string' },
		{ name: 'name', type: 'string' }
	]
});

var itemTemplateStore = Ext.create('Ext.data.Store', {
	model: 'ItemTemplateModel',
	autoLoad: false,
	proxy: {
		type: 'memory',
		reader: {
			type: 'json',
			root: 'entries'
		}
	}
});

var comboBox = Ext.create('Ext.form.field.ComboBox', {
	store: itemTemplateStore,
    queryMode: 'local',
	fieldLabel: 'Item Template',
	name: 'template',
	displayField: 'name',
	valueField: 'id',
	editable: false,
	typeAhead: false,
	triggerAction: 'all'
});

Ext.create('Ext.form.Panel', {
    title: 'Form',
    renderTo: Ext.getBody(),
    items: comboBox
});

var extraData = { entries: [
    { id: 184, name: 'Item4', imageUri: 'parts/speed/lv5/{1}' },
    { id: 183, name: 'Item3', imageUri: 'parts/defence/lv5/{1}' },
    { id: 182, name: 'Item2', imageUri: 'parts/attack/lv5/{1}' },
    { id: 173, name: 'Item1', imageUri: 'parts/attack/lv2/{1}' }
]};

setTimeout(function() {
    itemTemplateStore.loadRawData(extraData);
}, 2000);