TIWCGJQGridOptions.OnSortCol Property
Raised immediately after sortable column was clicked and before sorting the data. index is the index name from colModel, iCol is the index of column, sortorder is the new sorting order - can be 'asc' or 'desc'. If this event return 'stop' the sort processing is stopped and you can define your own custom sorting
published property OnSortCol: TIWCGJSonFunc index 100 read GetFuncValue write SetFuncValue stored IsFuncStored;