[Zope-dev] Dependencies question

[Wichert Akkerman]

Previously Dan Korostelev wrote:
> I was looking at dependencies of various zope.* packages and see that
> some packages depend on other because of ZCML directives and some are
> not. For example:
> 
> The zope.app.catalog package depends on zope.app.component, but
> doesn't use it anywhere in non-testing code, however it does use the
> ``class`` directive, registered in zope.app.component.
> 
> While the zope.app.keyreference doesn't depend on zope.app.component
> at all, but uses ``class`` directive as well.
> 
> So, the question is: what's the common policy for that? Should we
> depend on packages that is used in ZCML or not? Or maybe ZCML-related
> dependencies should be in some extras_require, say "zcml"?

There is certainly precendence for that (zope.component and zope.i18n
iirc).

> Personally, I think, that extras_require way is a nice compromise for
> that. Because many of packages can be used greatly without ZCML
> configuration, but getting ZCML-reqired dependencies should be easy.

+1

Those zcml dependencies make it a lot more painful to use zope.*
packages in other environments.

Wichert.

-- 
Wichert Akkerman <wichert at wiggy.net>    It is simple to make things.
http://www.wiggy.net/                   It is hard to make things simple.