[Zope-dev] ZPatterns sub-Specialist traversal

[Michael R. Bernstein]

With some help from the kind folks on #zope, this has been
solved.

"Michael R. Bernstein" wrote:
> 
> Here is what I've done:
> 
> ArchiveImages (Specialist)
>  defaultRack
>   traversal_method (Python Script)
>   traversal (SkinScript)
>  Renderings (sub-Specialist)
>   defaultRack

This was wrong in a couple of ways, here is how it needs to
be layed out:

ArchiveImages (Specialist)
 traversal_method (Python Script)
 defaultRack
  traversal (SkinScript)
 Renderings (sub-Specialist)
  defaultRack

As you can see, the Python Method needed to be moved from
within the Rack up into the Specialist.

> traversal_method has 'REQUEST, name' as parameters, and the
> following body:
> 
> return getattr(container.Renderings, name)

The body of the traversal_method needed to change in two
ways:

 if name in ['index_html', 'editInstanceForm',
'editInstance']:
     return getattr(context, name)
 else:
     return container.Renderings.getItem(name)

First, it needed to pass unmolested those methods of the
ArchiveImage that were needed. Second, Specialists
apparently don't support getattr(), so I needed to change
this to call getItem() instead.

> The 'traversal' SkinScript has the following body:
> 
> WITH SELF COMPUTE __bobo_traverse__=traversal_method

The SkinScript works fine as-is.

HTH,

Michael Bernstein.