[ZPT] zope3-dev proposal on changing implicitly calling

Steve Alexander steve at z3u.com
Tue Jul 29 10:24:55 EDT 2003


Barry Warsaw wrote:
> On Mon, 2003-07-28 at 15:57, Steve Alexander wrote:
> 
> 
>>I'll discuss this on the Zope 3 list, but not on the ZPT list.
>>
>>For here, it is sufficient to say that for Zope 3 we want to control 
>>through policy whether something is implicitly called or not.
>>
>>The problem is not that you can explicitly not call using 'nocall:', but 
>>that the component is always called if it has a '__call__' method.
> 
> 
> I've only been able to pay tangential attention to this thread, but...
> how does this tie into the ability to call callables in the middle of a
> path expression?   I /really/ want that!

We do that already in Zope 3. In Zope 3, Zope 3's traversal machinery 
gets used to traverse path expressions. It is the responsibility for the 
traversal adapter for a particular object to say how to traverse it, and 
whether to call it.

The only problem comes with the last object from the path. TALES makes 
the decision of whether to call or not, rather than Zope 3. For Zope 3, 
this is inconsistent.

--
Steve Alexander





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