SMART datagrid v.1 > Classes > DataColumn
If it is true, the user can click filter handle of this column header to change filtering state. filteringEnabled of operateOptions should also be set as true.
You can specify whether it is sortable through sortable property.
Defaults to true.
var col = grid.focusedIndex().column;
if (!col.filterable()) {
col.setFilterable(true);
}