I am trying to display a list of reports in a grid grouped by attributes in a parent object. I have searched the forums but have not been successful...

The JSON data:
Code:

{"d":{"__type":"DataObject","Success":true,"Message":"","RowCount":1,"Rows":[{"Id":1,"Name":"Test Data","SystemNames":["test1","test2"],"DailyReports":[],"WeeklyReports":[{"FileName":"TestReportA.pdf","FileCreationDate":"\/Date(1269968254271)\/"}],"MonthlyReports":[{"FileName":"TestReport1.pdf","FileCreationDate":"\/Date(1269968254271)\/"},{"FileName":"TestReport2.pdf","FileCreationDate":"\/Date(1269968254271)\/"}]}]}}
ExtJS Code:
Code:

      // Setup the json data store
    var jsonStore = new Ext.data.GroupingStore({id: 'JsonDataStore',
                                                autoLoad: false,
                                                proxy: new Ext.data.HttpProxy({url: '<Web Service URL>',
                                                                               method: 'GET', jsonData: {},
                                                                               headers: {'Content-Type': 'application/json; charset=utf-8;'}
                                                                               }),
                                                reader: new Ext.data.JsonReader({root: 'd.Rows', idProperty: 'Id',
                                                                                 totalProperty: 'd.RowCount', messageProperty: 'd.Message',
                                                                                 fields: [{name: 'Id', type: 'int'}, 'Name',]
                                                                                 }),
                                                groupField: 'Name',
                                                groupOnSort: true,
                                                sortInfo: {field: 'Name', direction: 'DESC'}
                                                });

    // Load the json data store
    jsonStore.load();

    // Setup the column model
    var columnModel = new Ext.grid.ColumnModel([{id: 'Id', header: "Property Identity", dataIndex: 'Id',
                                                 width: 50, readOnly: true, sortable: true, hidden: false},
                                                {id: 'Name', header: "Name", dataIndex: 'Name',
                                                 width: 150, readOnly: true, sortable: true, hidden: false}
                                                ]);

    // Setup the grid
    var myGrid = new Ext.grid.GridPanel({id: 'MyGrid', ds: jsonStore, cm: columnModel,
                                                 autoExpandColumn: 'Name', height: 500, width: '100%', stripeRows: true,
                                                 collapsible: false, loadMask: false, renderTo: myGridDiv,
                                                 view: new Ext.grid.GroupingView({forceFit: true})
                                                 });
I have successfully displayed a grid showing the Id and Name with grouping and sorting - based on some good examples. I have not been able to figure out how to display the FileName or FileCreationDate along with the Id and Name. To make this a little more complicated, there is no guarantee that each of the attributes/objects will contain data...

Thanks for the help!
-Dan