[Zope3-dev] Re: Interface implementation declaration weight (was Re: View lookup changes in Zope 3.2?)

[Jim Fulton]

Jeff Shell wrote:
> On 12/13/05, Jim Fulton <jim at zope.com> wrote:
> 
>>Jeff Shell wrote:
>>...
>>
>>>Going through a lot of debugging, it looks as through it has to do
>>>with how things are ranked in
>>>zope.interface.adapter.AdapterLookup.lookup() for multi-adapters.
>>
>>Yup.
>>
>>I don't know enough about the relationshipd between your content
>>interfaces, to comment directly, but I will note that the intent
>>was that content interface would have precedence over skin.  This
>>was not the case before due to a bug in  multi-adapter lookup.
> 
> 
> I'm sure that's the issue here. The software worked "fine" in 3.1, or
> basically worked in a way that I assumed was fine.
> 
> The situations where this is affecting us is in some of our oldest
> major Zope 3 code, and it's code we've had issues with before. Those
> issues, and this one, are likely due to it being early code and us
> (namely me) still learning a lot of core concepts and maybe not
> applying them so well.
> 
> So I have a new question: with the different ways that 'implements'
> and 'provides' may be applied to an object, is there a document that
> details how those affect the interface/spec resolution order?
> 
> I'm thinking of things like interface inheritance, class inheritance,
> ZCML's 'implements' directive, 'zope.interface.implements(IFoo)' in a
> Python class statement, and any interfaces said to be provided by a
> particular instance - how much weight does each method provide?

I'll write up a discussion of this ans check it in.  Feel free to
nag me if I don't get this done in a couple of days. :)

Jim

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