Kendo Grid - Aggregate not working on complex data objects

Hello, as promised, here's Kendo solution :

The behavior you are experiencing is caused by the fact that the 
"path" you have specified will be used as a key in the map created as 
result of the aggregation. Producing a object similar to the following:



	{ "foo.bar" :  { sum: 30 } }



Unfortunately, this construct is not supported by the footer template 
generation and will not be resolved correctly. A possible workaround for
 this scenario is to use a function instead. I have modify the sample in
 order to illustrate this.

var grid = $("#grid").kendoGrid({
    dataSource: {
        data: [
            {"foo": {"bar": 10}},
            {"foo": {"bar": 20}}
        ],
    
        aggregate: [
            {field: "foo.bar", aggregate: "sum"}
        ]
    },
    columns: [
        {
            field: "foo.bar",
            footerTemplate: function(data) { return "Sum: " + data["foo.bar"].sum; }
        }
    ]   
}).data("kendoGrid");