[Zope] How to properly do navigation Bar without un-authorized sub-objects?

[Brad Clements]

I need to "hand generate" a navigation bar, showing only those subobjects 
to which the current user is authorized to view.

It seems as if I'd get an AttributeError when trying to access items that I 
can't access, but with LoginManager it pops up a login box.. Which I don't 
want.

My design is to have each "folder" have its own "DrawNavBar" DTML-
Method, whose job it is to generate it's own html.. If that folder has sub-
folders, than that folder's DrawNavBar should call it's sub-folders 
DrawNavBar functions.

To avoid a recursive loop resolving DrawNavBar, I use aq_explicit, like 
this:

<dtml-try>
<dtml-var "_.getattr(PARENTS[-1].Z.Admin.aq_explicit,'ShowNavBar')(_.None,_)">
<dtml-except AttributeError>
</dtml-try>


The problem with this is that I get a login prompt from LoginManager if I'm 
anonymous.. 

I suppose I could use something like dtml-in to only show those objects to 
which I'm authorized, but I don't want to enumerate the contents of the 
folder, since I know exactly what I'm looking for.

So.. given an explcit path, how can I find out if the current user can 
'access' that path item, such as a DTML-method?

I'm not asking Zope to confirm that the object exists if I don't have access 
to it.. just say "no such object" or "here's the object" and not use 
acquisition to find it up the path.

Ideas?

Thanks


Brad Clements,                bkc@murkworks.com   (315)268-1000
http://www.murkworks.com                          (315)268-9812 Fax
netmeeting: ils://ils.murkworks.com               AOL-IM: BKClements