Kendo grid with nested data causes error when filtering on null objects

Hi,

Our datasources data are generated with nested objects from the server and sometimes, some values can be null.

At first, I had to do custom template functions for every column to display them according to their values, so I created a function that either returns the value of the object, or an empty string if on any given level, it is null. However, if I try filtering that column, an exception is thrown.

I have created a sample code to show this error, just try adding a filter to the column to see the error : http://jsfiddle.net/UXBcW/1/

Thanks