[Zope-dev] [Plone-developers] experimental.broken - Graceful handling of broken interfaces and components in the ZODB

[Ross Patterson]

Raphael Ritz <r.ritz at biologie.hu-berlin.de> writes:

> On 11/7/11 10:36 AM, Malthe Borch wrote:
>> On 7 November 2011 09:17, Ross Patterson<me at rpatterson.net>  wrote:
>>> The intention of this package is to see if the implementation of broken
>>> object handling is correct and robust enough to merge into
>>> zope.interface and zope.component themselves.  Is this the right
>>> approach?  If not why and what would be better?  How might this approach
>>> be improved?
>>
>> (removed plone-dev from cc).
>>
>> Isn't it symptom treatment though?
>
> Yes, it is but the symptom is severe and not uncommon.
> The problem Ross is addressing here just happens way too often
> in the real world to simply say "Sorry, user error".

Exactly.  There is also precedent.  The same argument Malthe offers
would suggest we shouldn't have ZODB.broken, but we do.  We have it
because the ZODB is too fundamental a piece of such applications to let
it break so completely when code is missing.  The same is true of the
ZCA, it's too fundamental a piece of such applications to let it break
completely when code is missing.

Ross

>> If you've got an add-on which adds
>> marker interfaces to "general objects", shouldn't that add-on remove –
>> or no longer provide – those same interfaces when it's uninstalled? At
>> least in Plone, you can easily query content objects providing a
>> particular set of interfaces.
>>
>> I think it's a non-goal to be able to run a system without all the
>> required software – which is how I understand it when you just do a
>> "hard remove" of an add-on without a prior "soft remove".
>>
>> \malthe
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