"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