[Zope-CMF] Re: Delete trouble
Philipp von Weitershausen
philipp at weitershausen.de
Wed Mar 28 02:16:03 EDT 2007
On 27 Mar 2007, at 20:57 , Dieter Maurer wrote:
> As so often, we have completely different views on how things
> should be:
> When I have an "IObjectBeforeDeleteEvent" subscriber which
> should update the unique ID tool, then it can assume that
> there is indeed a unique ID tool. And if the assumption is
> wrong, an exception should result.
What makes you think you can make that assumption? This is Zope 2 all
over again, where things just have to be there. That won't help
making things more flexible.
> We have this situation here: there should be (and is) a unique
> id tool but the local registrations have not been performed.
Nope, we're just not operating in a place where we can get to the
tool. It's standard acquisition semantics.
> An exception is better than silently omit the update of the existing
> unique id tool.
> You could argue that the local id tool does not need to be updated
> as the complete site (including the tool) gets deleted.
> But would the effect be different, if I used:
> Or in other words, is attribute lookup entailed in traversal?
> If it is not (which I assume), then your "defensive programming"
> would hide inconsistencies in the unique id tool -- similar
> to a "defensive try: .... except: pass".
What kind of inconsistencies? We're deleting the thing anyway, what's
the point to update it?
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