[Zope3-Users] Re: [z3-five] zope.viewlet and zope.contentprovider - options for Zope 2 and Plone 3

[Jean-Marc Orliaguet]

Stephan Richter wrote:

>On Sunday 09 April 2006 20:33, David Pratt wrote:
>  
>
>>The Z2 integration will be started soon at a sprint soon. Viewlets and
>>portlets seem pretty synonymous and cpsskins provides a way to
>>manipulate portlets visually which is very nice.
>>    
>>
>
>Viewlets are not portlets! Portlets are much more restrictive and the industry 
>has a very specific meaning for the term, which differs from both, Plone's 
>and CPS skins', usage of the term. 
>
>Regards,
>Stephan
>  
>

Actually I've looked into creating a generic "viewlet" portlet that 
would make it possible to reuse viewlets in cpsskins (for instance by 
using the visual portlet editor). A feature that is missing is that 
there is no easy way to find the list of registered viewlets. A viewlet 
lookup mechanism would be needed, for instance a utility that returns a 
list vocabulary items with viewlet's name and the factory.

also something that seems strange is that some viewlets are dependent on 
viewlet managers:


see for instance: zope/app/boston/viewlets/toolbar:

class ToolBarViewlet(object):
    """I18n info viewlet."""

    implements(IToolBarViewlet)

    def macros(self, name):
        return self.manager.macros(name) <<<<<<<<<<

    def menus(self, menuId):
        return getMenu(menuId, self.context, self.request)


So if I want to render a toolbar viewlet I need to instanciate the 
corresponding viewlet manager. I would understand this if I wanted to 
render all viewlets in a given area of the page, but if I want to render 
just one viewlet?

Basically it introduces a cycle in the design: viewlet managers depend 
on viewlets and viewlets depend on viewlet managers to be rendered.


/JM