[Zope] Indirect calling of extensions?

[Tres Seaver]

Glenn Rogers <zope-list@gacela.demon.co.uk>
> To: zope@zope.org
> Subject: Re: 
> 
> On Fri, Mar 24, 2000 at 03:28:09PM -0600, Tres Seaver wrote:
> > Glenn Rogers <zope-list@gacela.demon.co.uk> wrote:
> >
> > > Imagine I have a python extension, with zope id pyFetch
> > >
> > >   def Fetch (self, href):
> > >     ...
> > >
> > > I want to call this in a manner similar to:
> > >
> > >   <!--#let call_method="'pyFetch'"-->
> > >     <!--#in sql-method-returns-href-->
> > >       <!--#var "_[call_method]( href )"-->
> > >     <!--#/in-->
> > >   <!--#/let-->
> > >
> >
> > I don't know what you mean by "python extension" -- is this an
> > ExternalMethod?
> >
> Yes.  It lives in the zope extensions directory though - blame lack of sleep.
> 
> > In a DTML method contained/acquired by that folder::
> >
> >   <ul>
> >   <dtml-in list_hrefs mapping>
> >     <li><dtml-var "this().pyFetch( href )"></li>
> >   </dtml-in>
> >   </ul>
> >
> Problem: In real life, I don't know that I'm calling pyFetch, it could be
> pyDontFetch or pyGoToSleep etc (the "#let call_method" is in another DTML
> method and there are a few alternatives).  All I know is that it shares
> the same signature.  Works fine if you call it directly.
> 
> Is there a better method than the equivalent of
> 
>   <!--#if "call_method=='pyFetch'"-->
>     <!--#var pyFetch( href )-->
>   <!--#elif "call_method=='pyDontFetch'"-->
>     <!--#var pyDontFetch( href )-->
>   ...

Try this (untested), assuming the name of the method you want to call is stored
somehow in the variable 'methodName'::

  <dtml-let methodToCall="_[ methodName ]">
    <dtml-in list_hrefs mapping>
      <dtml-var "methodToCall( this(), href )">
    </dtml-in>
  </dtml-let>

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Tres Seaver         tseaver@palladion.com    713-523-6582
Palladion Software  http://www.palladion.com