[Zope-dev] Generated Images Again

[David S. Harrison]

As you might recall, I am on a quest to get Zope to serve up automatically
generated images.  I am nearly there.  In a simple example, my DTML
looks like the following:

<!--#var standard_html_header-->
<h2><!--#var title_or_id--></h2>
<p>
<IMG SRC="GenerateImage">
</p>
<!--#var standard_html_footer-->

My external method kind of looks like this:

def GenerateImage(self, RESPONSE):
    bits = functionThatWritesImageIntoAString()
    RESPONSE.setHeader('content-type', 'image/png')
    return bits

This works fine.  However, functionThatWritesImageIntoAString()
actually takes arguments.  So, I attempted the following:

def GenerateImage(self, RESPONSE, arg):

Then I tried several possibilities in DTML:

<IMG SRC="GenerateImage(arg)">
<IMG SRC="GenerateImage(RESPONSE,arg)">

I tried permuting arguments.  I can't convince it to work.  It
appears that I don't know the magic to tell Zope to pass arguments
to the external method.  I am looking for suggestions.

There is a really nasty workaround: I could use <dtml-call> before
the <IMG> tag to pass arguments implcitly (through globals) to
the GenerateImage method.  But this seems really ugly.  I am
looking for a more graceful solution.

				David S. Harrison
				(dsh@magma-da.com)