[Zope-dev] Re: [z3-five] relocating Zope 2 core interfaces - a proposal

[yuppie]

Hi!


Martijn Faassen wrote:
> yuppie wrote:
> [snip]
> 
>> Current State
>> =============
>>
>> Five (now part of Zope 2.8) ships with one big interfaces.py file that 
>> contains z3 interfaces for Zope 2 core classes. (There are also some 
>> five specific interfaces in that file, but they are not subject of 
>> this proposal.)
>>
>> interfaces.zcml states that Zope 2 implements these interfaces, but 
>> there are no tests to verify that and in fact many of these interfaces 
>> are broken in Five 1.0. (Yesterday I checked in some fixes to the Five 
>> trunk.)
> 
> 
> Note that they also need to be in the 1.0 branch, if this is to be in 
> Zope 2.8.

<sarcasm>Maybe it's better the interfaces are broken. That makes sure 
people don't use them extensively and might give us a chance to relocate 
them at a later point.</sarcasm>

>> I grepped through CMFonFive, SilvaDocBook and SilvaFlexibleXML: None 
>> of them use these interfaces.
> 
> 
> I think there's some code inside the Five tests that might use them. 
> There's also a chance someone else is using them, but admittedly the 
> risk of breaking something doesn't seem too big. This does deserve to be 
> called 1.1 though if we're breaking APIs (this would then derive from 
> the 1.0 branch, not the Five trunk).

Ok.

>> Proposed Solution
>> =================
>>
>> 1.) Adding ZCML that bridges existing z2 interfaces into the 
>> 'interfaces' module of their package. [Zope 2.8.0]
>>
>> 2.) Copying z3 interfaces from Five.interfaces to the 'interfaces' 
>> module of the corresponding package. Marking those in Five as Zope 2.7 
>> backwards compatibility cruft. [Zope 2.8.0]
> 
> 
>> 3.) Doing the same for Zope 2.7 with monkey patching code. [Five 1.0+]
> 
> 
> I don't understand this step; what are you proposing?

It might be better to use the new locations also for Zope 2.7. But the 
interfaces don't exist in Zope 2.7, so we would have to inject them into 
Zope 2.7.

>> 4.) Making interfaces.zcml point to the new locations. [Five 1.0+]
> 
> 
> While in Zope 2.8, we could add 'implements' in the Zope 2 code 
> directly, we don't need to do this from ZCML anymore.

As you state below, there might be issues with mixing five:implements 
and implements(). But if there are no issues, I agree that using 
implements() would be better.

> Another potential risk is Five doing five:implements to a class that 
> already has a Zope 3 style 'implements()'. I don't know what happens in 
> such a case...


Cheers,

	Yuppie