In all versions of Telerik controls released in 2013 the ability to implement custom FilteringBehavior
is available and you should be able to implement it without any concerns. On the other hand, the AsyncFitleringBehavior
was introduces with the Q2 2014 release version. So, if you need to create a custom AsyncFitleringBehavior
please check the following forum thread that provides a detailed information how to achieve this:
However, if that is not what you're looking for, please provide us some more detailed information about the desired by you functionality.
Hopes this helps.