A Sencha ExtJS checkboxgroup and checkbox listener example

A Sencha ExtJS checkboxgroup and checkbox listener example:

Ext.create('Ext.form.Panel', {
    title: 'Checkbox Group',
    width: 300,
    height: 125,
    bodyPadding: 10,
    renderTo: Ext.getBody(),
    items:[{
        xtype: 'checkboxgroup',
        fieldLabel: 'Two Columns',
        // Arrange checkboxes into two columns, distributed vertically
        columns: 2,
        vertical: true,
        listeners: {
            change: function(field, newValue, oldValue, eOpts){
                console.log('change:' + field.fieldLabel + ' ' + newValue.rb);
            }
        },
        items: [
            { boxLabel: 'Item 1', name: 'rb', inputValue: '1' },
            { boxLabel: 'Item 2', name: 'rb', inputValue: '2', checked: true },
            { boxLabel: 'Item 3', name: 'rb', inputValue: '3' },
            { boxLabel: 'Item 4', name: 'rb', inputValue: '4' },
            { boxLabel: 'Item 5', name: 'rb', inputValue: '5' },
            { boxLabel: 'Item 6', name: 'rb', inputValue: '6' }
        ]
    }]
});