[Zope] DTML Container?

[Mike]

Hello,

I wondered what is the simples (and efficient) way of implementing subj.

Let I explain first what it may be needed for.

Suppose we'd like to create a class modeling an article (newspaper
article, for example). An article has attributes 'title' and 'body' and
can contain zero or more photos. Article's body contains some HTML text
exposing those photos, if any. Note the images are aggregated by article
and should not be exposed anywhere else.

The simplest way is to subclass our Article from (Z)ObjectManager and
implement title and body as properties. On this way we are losing the
DTML capabilities which we were have in DTML document/method. This is a
big lost, indeed (at least we have to write <img src=img width=...
height=... alt=...> instead of just <dtml-var img>). The one way to keep
object DTML-aware is to subclass DTML method also. I tryed this approach
and found this working, but with one exception: <dtml-var img> does not
work. It does not work on _any_ callable objects. The workaround is
<dtml-var "img.tag()"> or something equivalent. This is also not so
good. 

Another approach is to render properties as DTML strings using external
method:

from DocumentTemplate import HTML

def render_dtml (text='',mapping={},**kw) :
    html = HTML(text)
    return html(client=None,mapping=mapping)

This also works fine but also has a dark side. As I found in sources,
Zope stores DTML methods and documents in parsed form, this was done not
just for fun, I guess. I think the parser is very expensive thing so on
this way we get a great performance impact, right?

Does anybody have any solution or just mention on it?

Best,
Mike

P.S. Why nobody asked this before???