[Zope-CMF] Re: GenericSetup extension profile import step mis-feature

[Hanno Schlichting]

Tres Seaver wrote:
> Martin Aspeli wrote:
> 
>> Tres Seaver wrote:
>>> 'importVarious' is a brutal hack:  better to focus efforts on making it
>>> disappear.  The entire point of the tool is to externalize configuration
>>> as declarative data in the profile;  accomodating imperative
>>> configuration is not something I care to support.
>> I think that's a bit puritanical. Sometimes it's just not possible to have
>> declarative configuration for anything, either for time or complexity
>> reasons. There will be setup tasks that can only feasibly be achieved in an
>> imperative way, and need to run during the installation of a product.
> 
> My point is that imperative configuration creates a logically-insoluble
> rats-nest:  Goedel's Law comes into play, because imperative stuff
> induces ordering dependencies, which are irrelevant for purely
> declarative stuff.
> 
> Plone's 'importVarious' was supposed to be a "temporary" hack when Rob
> added it almost two years ago;  it should *still* die.  In the meantime,
> it is the responsibility of the perpetrator to obey the Hippocratic
> maxim, "first do no harm."

Just as a side note, Plone itself (not counting the ones from its
dependencies) currently has five different interdependent import various
handlers. One is enabling the portal as a Zope3 site, two are
quickinstalling products based on extension profiles (which are again
dependent on each other), one is doing some configuration that really
should be in xml files and one is installing content. The content
creation as well as some site settings are dependent on the current
browser language.

All this works reasonable well right now and while I don't like all of
it, I think realistically we need to have some sensible support for
imperative import handlers for some time in the future.

Hanno