Hello. Hmm, I think I understand Rafael's proposed navigation, though I'm not sure I understand Jeremy's questions.
In any case, if I understand Rafael's proposed navigation, it should be reasonably straightforward to implement it by remixing bits of existing code. I haven't seen a compelling case for callbacks yet, but there may be one.
The tabs are queried out of the portal_pages table. The proc responsible for this is dotlrn::portal_navbar in packages/dotlrn/tcl/navigation-procs.tcl. The My Space pages are part of the user's personal portal, whose id can be found from dotlrn::get_portal_id.
Putting the My Space etc. navigation on all pages would just mean querying out the pages for the user's personal portal in addition to the pages for whatever class portal the user happens to be visiting.
