Display JSON object in YUI Datatable

I'm trying to display the following JSON object using YUI DataTable. I was able to show the lastName, firstName, startDate, employeeCode, employeeStatus successfully in YUI DataTable. But I couldn't show the values in the inner object. In the columnset I tried user.userId and it is displayed as {value} in the DataTable.

[    
{
            "lastName": "MyLastName",
            "firstName": "MyFirstName",
            "startDate": "11-11-11",
            "employeeCode": "124",
            "employeeStatus": "Permanent",
            "user": {
                "key": {
                    "name": null,
                    "parent": {
                        "name": null,
                        "parent": null,
                        "id": 855,
                        "namespace": "",
                        "complete": true,
                        "kind": "Employee"
                    },
                    "id": 856,
                    "namespace": "",
                    "complete": true,
                    "kind": "Users"
                },
                "salt": null,
      开发者_如何转开发          "userId": "myemail@example.com",
                "status": true,
},
{
...
}
]

Here is the Javascript code:

<script type="text/javascript">
YUI().use("jsonp", 'sortable', 'json-parse', 'datatable', "datatable-sort", "io", "node", function(Y) {
var nestedCols = [ 
    {key : "employeeCode",label : "Employee Code", sortable:true},
    {key : "firstName", label : "First Name",sortable: true},
    {key : "lastName", label : "Last Name", sortable:true},
    {key : "user.userId", label : "Email Id"},
    ];
Y.io('/Employee/AjaxList', {
on : {
success : function(tx, r) {
var data = Y.JSON.parse(r.responseText);
var table = new Y.DataTable.Base({
        columnset : nestedCols,
        recordset : data,
        }).plug(Y.Plugin.DataTableSort);
        table.render("#empTable");
}
}
});
});
</script>

is there anything wrong with this code snippet? How can I show the value of user.userId in DataTable?

Note: The JSON is generated using Jackson and application is developed in GAE/J

UPDATE:

I used DataSource following the suggestion by @Luke. This time I got an empty DataTable with only the headers. Here is the code snippet.

YUI().use("datasource-get", "datatable-base", "datatable-datasource","datasource-arrayschema", function (Y) {

var url = "/Employee/AjaxList?";
var dataSource, table;

dataSource = new Y.DataSource.Get({ source: url });

dataSource.plug(Y.Plugin.DataSourceArraySchema, {
        schema: {
                resultFields: ["firstName", "lastName"]
                }
        });

var cols = ["firstName", "lastName"];

table = new Y.DataTable.Base({
                columnset: cols,
});

table.plug(Y.Plugin.DataTableDataSource, { datasource: dataSource });

table.render("#empTable");

table.datasource.load();
});

You'll need to use datasource-jsonschema to parse out the nested values. See this example: http://yuilibrary.com/yui/docs/datatable/datatable-dsget.html

You should be able to follow those steps, replacing Y.DataSource.Get with Y.DataSource.IO

I got the solution from YUI Forums following my post in the forum: http://yuilibrary.com/forum/viewtopic.php?f=92&t=8685

Here is the code which worked for me:

YUI().use( "datasource-io", "datasource-jsonschema", "datatable-base", "datatable-datasource", "datatable-scroll", 
           function (Y) {
    var cols = [    
            { key: "name", label: 'Name'  }, 
            { key: "email",  label: "Email"  },
            { key: "user.username", label: 'Username'  },
            { key: "user.password", label: 'Password'  },
        ];
    car url = "/Employee/AjaxList";
    var ds = new Y.DataSource.IO( { 
        source:url
     });
     ds.plug(Y.Plugin.DataSourceJSONSchema, {
            schema: {
                resultFields: [ 'name', 'email', 'user.username', 'user.password' ],
            }
        });
    var dt = new Y.DataTable.Base({
        columnset:cols } )
        .plug(Y.Plugin.DataTableDataSource, {datasource:ds});
    dt.render("#dtable");
    dt.datasource.load();
});

Hope this helps somebody else who is struggling with DataTable & DataSource.