[Zope] DTML difficulties

[Nolan Darilek]

I'm working on my first zope product and, while everything has gone
relatively smoothly so far, I'm having some issues.

The product is a folderish object which contains 3 subfolders, each of
which contains a specific type of object. The structure looks
something like this:
work/: Main folder, UI, etc
       jobs/: List of all jobs
       projects/:
       taskforces/:

Each folder contains a job, project or taskforce object, as well as
the UI to manage them.

Projects and taskforces are simple objects with names, descriptions,
etc. Logic will be attached to these classes so that, when instances
are viewed, they will search for jobs which are assigned to them. Each
job can be assigned to multiple projects/taskforces.

Now, the difficulty. I'm working on the UI for the job add form, which
is in work/jobs. The form needs to iterate over the contents of
projects/ and taskforces/, and I can't figure out how. Here's what
I've tried:

<tr>
<th align="LEFT" valign="TOP">Taskforces</th>
<td align="LEFT" valign="TOP">
<select multiple name="taskforces:list">
<dtml-in "PARENTS[1].taskforces">
<option value="<dtml-var id>"><dtml-var title_or_id</option>
</dtml-in>
</select>
</td>
</tr>

<tr>
<th align="LEFT" valign="TOP">Projects</th>
<td align="LEFT" valign="TOP">
<select multiple name="projects:list">
<dtml-in "PARENTS[1].projects">
<option value="<dtml-var id>"><dtml-var title_or_id</option>
</dtml-in>
</select>
</td>
</tr>


And the error I get is:

|    |Error Type: TypeError                                                  |
|    |Error Value: unsliceable object                                        |

Traceback (innermost last):
  File /usr/lib/zope/lib/python/ZPublisher/Publish.py, line 222, in publish_module
  File /usr/lib/zope/lib/python/ZPublisher/Publish.py, line 187, in publish
  File /usr/lib/zope/lib/python/Zope/__init__.py, line 221, in zpublisher_exception_hook
  File /usr/lib/zope/lib/python/ZPublisher/Publish.py, line 171, in publish
  File /usr/lib/zope/lib/python/ZPublisher/mapply.py, line 160, in mapply
    (Object: ESPWorkRequestAdd)
  File /usr/lib/zope/lib/python/ZPublisher/Publish.py, line 112, in call_object
    (Object: ESPWorkRequestAdd)
  File /usr/lib/zope/lib/python/App/special_dtml.py, line 120, in __call__
    (Object: ESPWorkRequestAdd)
  File /usr/lib/zope/lib/python/DocumentTemplate/DT_String.py, line 528, in __call__
    (Object: ESPWorkRequestAdd)
  File /usr/lib/zope/lib/python/DocumentTemplate/DT_In.py, line 672, in renderwob
    (Object: PARENTS[1].taskforces)
  File /usr/lib/zope/lib/python/OFS/ObjectManager.py, line 617, in __getitem__
    (Object: RoleManager)
  File /usr/lib/zope/lib/python/OFS/ObjectManager.py, line 257, in _getOb
    (Object: RoleManager)
TypeError: (see above)


Can anyone offer any advice?