Problem binding to object stored in grid column

I'm not entirely sure if this is even possible. I thought it might be a job for deep binding, but I couldn't get that to work.



The fiddle http://ift.tt/1EO8iRg shows a simple stored, with a bound grid, and a form bound to the grid.



Selecting rows in the grid updates the form as expected, and editing the firstName or lastName fields in the form updates the grid as expected, but editing the properties of the data column does not update the grid.



Am I missing something basic or is this just not possible to do?

Problem binding to object stored in grid column