[Zope] dtml-tree with multiple objects

[Dennis Allison]

Navigation for a site I have in progress uses dtml-tree to build it's left index.
The left index display, as designed, will include tree's derived from several 
objects (call them A, B, and C).  The particular objects and the number of objects
will vary depending where the user is in the site.

dtml-tree is limited to a single tree per page, presumably because it uses a 
cookie to store the expansion state.

So, the question is, how to implement this scheme.  My current thought is to create a 
Product which wraps the various objects to be displayed and implements tpValues and 
the like for the collection.  dtml-tree applied to an instance of the Product would 
have the properties I want (or so I believe).

A search for an existing product of this sort has turned up nothing.  Anyone have pointers
to a product or experience trying to do this?

-dra