Splitting aggregated JSON response using a function DataSource

YAHOO.util.Event.onDOMReady(function () {

var Ex = YAHOO.namespace('example');

YAHOO.util.Connect.asyncRequest('GET','data.php',{
    success : function (o) {
        var data = YAHOO.lang.JSON.parse(o.responseText);

        function dataMarshaller(section) {
            return data.records[section] || [];
        }

        Ex.dataSource = new YAHOO.util.DataSource(dataMarshaller, {
            responseType : YAHOO.util.DataSource.TYPE_JSARRAY,
            responseSchema : {
                fields : ['foo','bar','baz']
            }
        });

        Ex.columns = [ { key: 'foo' }, { key: 'bar' }, { key: 'baz' } ];

        Ex.dataTable = new YAHOO.widget.DataTable('tbl1', Ex.columns,
            Ex.dataSource, { initialRequest : 'todo' });

        Ex.dataTable = new YAHOO.widget.DataTable('tbl2', Ex.columns,
            Ex.dataSource, { initialRequest : 'doing' });

        Ex.dataTable = new YAHOO.widget.DataTable('tbl3', Ex.columns,
            Ex.dataSource, { initialRequest : 'done' });
    }
});

});