sortable_column_header

Is there any way to make the plugin attach a class to its link?
(mainly sort direction).

This is rather ugly, looking for the purist way...

<th><%= link_to 'Name', sort_param('search', Directory, 'name'), {
:class => sort_param('', Directory, 'name' ).to_s.sub(/^(.+)-.+/,
'\1') } %></th>

yields:
<th><a href="..." class="sortdesc">...</a></th>