How to update badgeText in Sencha Touch (Ext.Container)

Currently I'm a newbie in Sencha and I want to update the badgeText in Sencha Touch from the store count in Ext.Container, Please see my code below for your reference Thank you and God bless.

Ext.define('XX.view.Menu',{extend: 'Ext.Container',xtype: 'menu',config: { cls: 'mainmenu', docked: 'left', top: 0, left: 0, bottom: 0, zIndex: 0, width: 266, padding: '0 0 0 0', open: false, scrollable: 'vertical', defaultType: 'button', defaults: { textAlign: 'left' }, scrollable: { indicators: false }, items: [{ text: 'Home', ui: 'mainmenu', iconCls: 'home', itemId: 'home' },{ text: 'Contact Us', ui: 'mainmenu', iconCls: 'form', itemId: 'contactus' },{ text : 'Notifications', ui: 'mainmenu', badgeText: '0', iconCls: 'form', itemId: 'notifications' }]},setParent: function(parent) { this.callParent(arguments); this.maskCmp = parent.add({ xtype : 'component', cls : 'mainmenu-mask', top : 0, zIndex : 5000, hidden : true, width : 9999, left : this.getWidth(), bottom : 0 }); this.maskCmp.element.on({ scope : this, touchend: 'onMaskRelease' });}});

How to update badgeText in Sencha Touch (Ext.Container)