[Zope3-dev] Number of languages in Zope 3

[Tres Seaver]

On Wed, 2003-04-09 at 06:52, Andy McKay wrote:
> >> But now you want to add a custom title attribute. Just because of this 
> >> you have to switch to a completely different syntax:
> >>
> >> <img
> >>   tal:replace="structure 
> >> python:here.Imagefolder.imagename.tag(title='MyTitle')"
> >>   src="" />
> >
> >> This is even hard to get for somebody who knows Python because you are 
> >> limited to having to use single quotes in the brackets due to some 
> >> limitation of the TAL parser.
> > 
> > I'd suggest writing this as a method in a supporting view class.
> 
> I don't know much about zope 3 at the moment, but how does writing a
> supporting view class make passing parameters from a template easier?
> 
> I think the point here is that the template, contains a value that you
> want to pass to the method. This is common when one does a tal:repeat,
> and then pass some value of that repeat off to a function for each
> iteration.

In Zope3, that idiom would typically be replaced by an intermediate
method on the view class which did the underlying work.  E.g., where in
Zope2 I might to something like:

  <div tal:repeat="snippet python:here.objectValues(['Some Type'])">
   <h3 tal:conetnt="python:snippet.headline(version='Brief')">HEADLINE
   >/h3>
   <div tal:content="python:snippet.teaseText(maxwords=100)>TEASE</div>
  </div>

in Zope3 I would add a method to the view class which did the heavy
lifting:

   def getSnippetInfo(self):
       results = []
       for snippet in [x for x in self.context.values()
                         if ISnippet.isImplementedBy(x) ]:
           results.append({'title' : snppet.headline(version='Brief'),
                           'tease' : snippet.teaseText(maxWords=100)})
       return results

The template then becomes much clearer:

   <div tal:repeat="info context/getSnippetInfo">
    <h3 tal:content="info/title">TITLE</h3>
    <div tal:content="info/tease">TEASE</div>
   </div>

Tres.
-- 
===============================================================
Tres Seaver                                tseaver@zope.com
Zope Corporation      "Zope Dealers"       http://www.zope.com