[z3-five] Wrapping Z2 interfaces (maybe, "bride of Frankenzope"?)

[Tres Seaver]

Martijn Faassen wrote:
> Tres Seaver wrote:
> 
>> For existing Zope2 applications which already declare and use Zope2 
>> interfaces, it seems natural to re-use those specifications.  I have a 
>> utility module (with a handful of tests) which exports 
>> 'fromZ2Interface', a function which introspects a Zope2 interface 
>> object and synthesizes an "equivalent" Zope 3 interface.
> 
> 
> Sounds like a useful thing to me. Interesting!
> 
>> I am currently using it in a scratch product, CMFonFive, 
> 
> 
> Very interesting name, that. :)
> 
>> to populate the 'interfaces' module, e.g.:
>>  
>>   from utilities import fromZ2Interface
>>
>>   from Products.CMFCore.interfaces.CachingPolicyManager \
>>       import CachingPolicyManager as _IZ2_CachingPolicyManager
>>
>>   ICachingPolicyManager = fromZ2Interface(_IZ2_CachingPolicyManager)
>>
>>   del _IZ2_CachingPolicyManager
>>
>>
>> The amount of noisy boilerplate in that module is painful:  I did take 
>> the opportunity to rename CMF interfaces, but that is the only real 
>> "value" the module adds.  I am pondering a ZCML directive which would
>> remove the need for the boilerplate;  something like:
>>
>>   <five:bolt-on
>>
>> source="Products.CMFCore.interfaces.CachingPolicyManager.CachingPolicyManager" 
>>
>>     target=".interfaces.ICachingPolicyManager"
>>     />
>>
>> Would the utility be useful in Five?  The directive?
> 
> 
> Yes, sounds like a good idea! Just to be clear, this would be a utility 
> as in 'utility module', not as in "Zope 3 utility" right? A module is 
> definitely a bit easier to integrate. Z3 utilities I think work (at 
> least global ones), but we haven't done a lot of testing.

Right.  It is literally called 'utilities.py' in 'CMFonFive'.

> I'd suggest another name for the directive though. Hm, perhaps 
> five:convert-interface
> 
> <five:convert-interface
> 
> zope2="Products.CMFCore.interfaces.CachingPolicyManager.CachingPolicyManager" 
> 
> zope3=".interfaces.ICachingPolicyManager"
> />
> 
> I'm not sure about the zope2 and zope3 attributes, though that would 
> make it fairly clear what we're dealing with.
> 
> Or perhaps we could call it five:bride :).

Heh, that was the first spelling I played with. ;)  I don't have any 
investment in how it is spelled.  I will prototype it using your spelling.

I will ask for SVN access on IRC.

Tres.
-- 
===============================================================
Tres Seaver                                tseaver at zope.com
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