Ext.regModel("Calendar", {
                        fields: [
                                {name: 'text',      type: 'string'},
                                {name: 'time',      type: 'string'},
                                {name: 'location',  type: 'string'}
                            ]
                        });

                    var calendarStore = new Ext.data.TreeStore({
                        model: 'Calendar',
                            proxy: {
                                type: 'ajax',
                                url : 'calendar.json',
                                reader: {
                                    type: 'tree',
                                    root: 'children'
                                }
                            }
                        });

                    var calendarList = new Ext.NestedList({
                        title: 'Calendar',
                        iconCls: 'time',
                        fullscreen: true,
                        displayField: 'text',
                        getDetailCard: function(recordNode, parentRecord) {
                            var record = recordNode.getRecord();
                            return new Ext.Panel({
                                tpl: [
                                    '<div>{location}</div>',
                                    '<div>{text}</div>'
                                ],
                                border: false,
                                bodyPadding: 5,
                                center: true,
                                data: record.data
                            });
                        },
                        store: calendarStore
                    });

                    calendarList.on('leafitemtap', function(subList, subIdx, el, e, detailCard) {
                        var ds = subList.getStore(),
                        r  = ds.getAt(subIdx);

                        console.log(r.get('location'));
                    });