[Zope-dev] Callable baseclass for ZClasses

[Chris Withers]

"Stefan H. Holek" wrote:
> 
> Taking ideas from the Renderable product, the ZCallable baseclass
> (PTK) and the __call__ thread on this very list, I created a Callable
> baseclass intended as a mixin for ZClasses.
> 
> class Callable:
> 
>   def render( self, client=None, REQUEST={}, RESPONSE=None, **kw ):
>     '''Calls index_html, if it exists, to render this object.
>     '''
>     self.isDocTemp = 1                  # pass me the namespace, please
>     local = getattr( self, 'aq_base', self )
>     if hasattr( local, 'index_html' ):
>       method = self.index_html
>       args = (self, REQUEST, RESPONSE)  # substitute self for client
>       return apply( method, args, kw )
>     else:
>       raise AttributeError, 'index_html'
> 
>   __call__ = render


I'd probably do that as (untested):

class Callable:

   isDocTemp = 1                  # pretend I'm a docTemplate
 
   def __call__( self, client=None, REQUEST={}, RESPONSE=None, **kw ):
     '''Calls index_html, if it exists, to render this object.
     '''
     local = getattr( self, 'aq_base', self )
     method = local.index_html
     args = (self, REQUEST, RESPONSE)  # substitute self for client
     return apply( method, args, kw )


> I went on to make a ZClass derived from Folder and Callable to effectively
> create a CallableFolder. Man, was I proud ;). This worked fine for me
> until I had to put some security on my CallableFolders. Removing 'View'
> for Anonymous keeps me from accessing a CallableFolder directly but it can
> still be used as a subtemplate (dtml-var x) from another DTML Document or
> Method. Bummer! Doing some tests I discovered that plain DTML Documents
> show the same behaviour (!), though DTML Methods throw 'Unauthorized' as
> expected.

Ewww... that's not very nice, Collector time:
http://classic.zope.org:8080/Collector/


> *) Do I have to take measures in my baseclass to properly access/pass
>    security contexts?

...shouldn't do, AFAIK.

> *) Or is there even prior art on such a baseclass or reasons why this just
>    cannot possibly work?

ZCallable, ZRenderable and FunctionTemplate are all in this space...

cheers,

Chris