[Zope-dev] Re: Adapters in Zope 2

[Santi Camps]

> > Casey Duncan wrote:
> > > Zope2 folders are designed for this. They are really just "blank
> > > objects" where you can specify your own methods in instance space.
> > > Traditionally in Zope2, there are two ways to do this: by adding
> > > "method" objects (External Methods, DTML methods, python scripts,
> > > ZPT) directly to the folder. Or by adding these objects "above" the
> > > folders and aquiring them which is a type of environmental
> > > inheritance. In the CMF this is codified in the skins tool which
> > > contains global methods which can be applied to basically any object
> > > in the site.
> > 
> > Great explanation - would you give me a hint on the CMF part ?
> > Which global methods do you speak of ?
> 
> The CMF has a "Tool" infrastructure. Tools are persistent objects
> typically at the top of the CMF site. Tools provide methods and
> configuration for use by all objects in the site via acquisition. For
> example, the membership tool (portal_membership), provides methods to
> access member information and member folders.
> 
> The portal_skins tool is special in that it actually contains framework
> and application defined method objects (scripts, templates, etc)
> organized into layers and configured into skins (which are lists of
> layers to use). The CMF Site object is a special "Skinnable" folder
> which allows methods available in the current skin (as described in the
> skins tool) to be acquired through it. This makes all of the method
> objects in the skin's layers globally available to all objects in the
> CMF site. 
> 
> This solves several problems, one of which is a tendancy of top-heavy
> hierarchies in zope where lots of objects are in the root because they
> need to be global. The skin and layer mechanisms allow different sets of
> methods to be available depending on the application, products
> installed, site policy and user preferences.
> 
> -Casey
> 

Very interesting.  That's what I was looking for.  I will try to extract
this mechanism from CMF.

Thanks a lot for your answers

-- 
Santi Camps
http://zetadb.sourceforge.net