[Zope] How to make a script return rendered dtml

[Tim Hicks]

I have a ZClass (testclass) which subclasses DTMLDocument, and within this
zclass, I have a script (python) called index_html.  Obviously, this script
is called each time an instance of testclass is requested.  Based on the
presence of a query string, I want to either return the document_src
(although with a few modifications), or simply return the rendered
instance... by this, I mean have all the dtml tags that are in the instance
evaluated.  So, my question is, how do I make Zope evaluate the dtml tags?

Here is what I have so far in my script:

------------
if context.REQUEST.QUERY_STRING == 'editor':
    print context.raw
else:
    print context

return printed
------------

The 'else' statement simply gives me things like,

<dtml-var standard_html_header>

I also tried 'else: render(context)', which was simply a guess on my part,
but I get a Zope error as follows:

Error Type: AttributeError
Error Value: validate

Can anyone enlighten me?

Cheers

tim