In the treelist, I would appreciate to have a loading component when the user performs actions (sort, filter). It is very disturbing, as the user doesn't know that the tree list is loading and he has to wait. Moreover this feature already exists for flat grids.
Hello,
For the time being, as a workaround, you could handle the requestStart and requestEnd events and manually display and hide a spinner with the kendo.ui.progress method over the TreeList.
Regards,
Preslav
Progress Telerik