[Zope-CMF] Re: [dev] refactoring listFilteredActionsFor: 2 questions

[Yuppie]

Hi!


Tres Seaver wrote:
> I think Yuppie is "kicking against the goads" here ;).

Doesn't feel like that ;)

> Caching an EC
> implicitly is going to be an evil bug magnet;  we would be better off
> adding a convenience method for constructing one from an object, and
> then just requiring clients to pass it in.

Well. I could live with your solution, it's a good alternative and no 
big deal to implement. But I would feel better if I'd understand what's 
wrong with my approach.

>> > So I experimented with storing the ExpressionContext in _v_skindata, 
>> > based on the assumption that
>> > i)  _v_skindata is always available in CMF
> 
> 
> _v_ anything is "volatile";  *don't* use it!

That was my first trial. The code I checked in on a branch uses REQUEST 
to store the cache.

>>Be aware that the same request may call "listFilteredActionsFor"
>>(or derivatives) for different objects...
> 
> 
> Right;  caching will break badly for anything but the cases which care
> only about the "published" object.

Not if you take care about that issue. See
<http://cvs.zope.org/CMF/CMFCore/Expression.py.diff?r1=1.5&r2=1.5.44.1>


Cheers,
	Yuppie