[ZPT] zope3-dev proposal on changing implicitly calling

[Florent Guillaume]

Steve Alexander wrote:
>> If I have a path:
>> /x/y/z
>> ...where x and z are callables (and x needs to be called to get 
>> somethat that y can be obtained from...) then what would the Zope 3 
>> ZPT/TAL look like to replace the contents of <i> with the result of 
>> calling z?
> 
> 
> For Zope 3, that should depend what traversal components are set for 
> traversing x and y and z.
> 
> If you say that x and z should be called, because it is their role in 
> the application to be called when traversed, then the TALES expression is:
> 
>   root/x/y/z
> 
> However, let's say 'z' has a __call__ method, but you don't want it to 
> be called when being traversed. Currently, you're stuck. It will always 
> be called.
> 
> The point of my proposal is that Zope 3 cannot control this properly 
> because the base TAL/TALES code always calls 'z' if it is callable.
> 
> 
>>> Can you summarise what you think the vote would be for?
>>
>>
>> Well, Florent proposed that, if the above example, you'd write:
>>
>> <i tal:contents="root/x/y/z"/>
> 
> 
> That's what I'd like too.
> 
>> I don't yet know what your opion would be, but at the moment, I'm in 
>> favour of Florent's
> 
> 
> Ok. What about when 'z' should not be called?

TALES has nocall: already, I'm not sure it's very elegant though...

Florent


-- 
Florent Guillaume, Nuxeo (Paris, France)
+33 1 40 33 79 87  http://nuxeo.com  mailto:fg at nuxeo.com