[Distutils] API for finding plugins

[Phillip J. Eby]

At 07:15 AM 2/9/2006 -0500, Jim Fulton wrote:
>Phillip J. Eby wrote:
>>I recently started work on adding egg support to Chandler ( 
>>http://chandler.osafoundation.org/ ), and ran into some interesting 
>>issues with respect to plugin discovery.  Specifically, it's not easy to 
>>do it well with the APIs that pkg_resources currently offers.  I suspect 
>>that others who've worked on plugin loading for application environments 
>>like Zope and Trac have probably run into similar issues.
>>I'm proposing, therefore, to add a new API to pkg_resources to make 
>>plugin-finding easier.  Among the requirements:
>
>I don't fully understand the goal here.  From later discussion, I think
>you envision a model where people drop eggs into some directory and an
>application should be able to analyze this directory to determine
>which ones to use, meaning which to include in some working set.
>In addition to automatically determining the working
>set, the application should be able to find the entry points in that
>working set.
>
>Does that capture what you want to do?

Yes, similar to the Zope 2 Basket product or Trac's plugin facility.  It 
also relates to non-entrypoint metadata, like the resource system that Ian 
and I have been discussing.  The goal there is to allow the located plugin 
eggs to offer translations, localizations, skins, etc. for other eggs to 
use.  I expect this will be relevant to Zope also, so I'd appreciate your 
input there as well.  I've been away from Zope 3 a little too long to know 
whether the ideas we're discussing can be made to work for it as well.