[Zope] creator/owner attribute of an object? Mime-type of a file object?

[Mike Fletcher]

I'm attempting to create a directory list (well, the final version will be
more complex, but this is where I'm stuck).  I'm looking for some way to get
the creator ID for all of the (file) objects in a folder.  I'm also
interested in getting the mimetype, but this is less critical.  Here's what
I have so far:

<dtml-in "PARENTS[0].objectValues( ['File'])">
url <dtml-var URL1>/<dtml-var id>
title <dtml-var title>
id <dtml-var id>
size <dtml-var size>
ddate <dtml-var bobobase_modification_time fmt="%m/%d/%Y">
owner 
mimetype <dtml-call "getContentType()">
</dtml-in>
<dtml-call "RESPONSE.setHeader('Content-Type', 'text/plain')">

Unfortunately, getContentType always seems to return null strings, and I
cannot find any attribute which shows the owner/creator attribute of the
object. If the creator is not available, the last editor would be fine.

Pointers appreciated,
Mike

__________________________________
 Mike C. Fletcher
 Designer, VR Plumber
 http://members.home.com/mcfletch