[Zope] external methods, returning objects...argh!

[Gerrie Roos]

This is the setup:

**childLookup  (python method):**

branches = context.childBranchesLookup(BranchParent = parentBranch)
tags = context.childTagsLookup(BranchName = parentBranch)
#these above are ZSQL results...

result = context.createNodeObj(branchResult = branches, tagResult =
tags)

return result


**createNodeObj (external method, calling createNodeObj):**

class _dummy:
    def __init__(self, name):
        self.name=name

def createNodeObj(branchResult, tagResult):
    c = []
    for branch in branchResult.dictionaries():
        c.append(_dummy(branch["BranchName"]))
    for tag in tagResult.dictionaries():
        c.append(_dummy(tag["CVSTagNo"]))
    return c


So the idea is to call childLookup, which passes ZSQL results on to
createNodeObj, and createNodeObj generates a list of objects and returns
it.  I know, I know I could've done it with an external method only...I
only learnt that too late.  Now I can't work with the resulting list of
objects in Zope!

for instance:

<dtml-in expr="childLookup(parentBranch = 'Main')">
    <dtml-var name>
</dtml-in>

results in:

'Authorization failed. Retry? '  popup in my browser.  Then cancelling I
get the following trace:

Zope Error

   Zope has encountered an error while publishing this resource.

   Unauthorized

   Sorry, a Zope error occurred.

   Traceback (innermost last):
     File
/usr2/GnatsPkg/src/Zope-2.3.0-src/lib/python/ZPublisher/Publish.py, line
222, in publish_module
     File
/usr2/GnatsPkg/src/Zope-2.3.0-src/lib/python/ZPublisher/Publish.py, line
187, in publish
     File
/usr2/GnatsPkg/src/Zope-2.3.0-src/lib/python/ZPublisher/Publish.py, line
171, in publish
     File
/usr2/GnatsPkg/src/Zope-2.3.0-src/lib/python/ZPublisher/mapply.py, line
160, in mapply
       (Object: test_index_html)
     File
/usr2/GnatsPkg/src/Zope-2.3.0-src/lib/python/ZPublisher/Publish.py, line
112, in call_object
       (Object: test_index_html)
     File
/usr2/GnatsPkg/src/Zope-2.3.0-src/lib/python/OFS/DTMLDocument.py, line
189, in __call__
       (Object: test_index_html)
     File
/usr2/GnatsPkg/src/Zope-2.3.0-src/lib/python/DocumentTemplate/DT_String.py,
line 538, in __call__
       (Object: test_index_html)
     File
/usr2/GnatsPkg/src/Zope-2.3.0-src/lib/python/DocumentTemplate/DT_In.py,
line 711, in renderwob
       (Object: childLookup(parentBranch = 'Main'))
     File
/usr2/GnatsPkg/src/Zope-2.3.0-src/lib/python/OFS/DTMLMethod.py, line
261, in validate
       (Object: test_index_html)
     File
/usr2/GnatsPkg/src/Zope-2.3.0-src/lib/python/AccessControl/SecurityManager.py,
line 144, in validate
     File
/usr2/GnatsPkg/src/Zope-2.3.0-src/lib/python/AccessControl/ZopeSecurityPolicy.py,
line 168, in validate
   Unauthorized: name

So can't I return a list of objects from an external method?

How will one then get the example of dtml-tree with external methods
shown in
http://www.zope.org/Members/anthony/tree-coding-tricks
to work?

Thanks!