[Zope-dev] Re: zcml entry points

[Chris McDonough]

On Oct 18, 2007, at 8:17 AM, Tres Seaver wrote:
> I may not *want* the other package's ZCML to be loaded:  some of its
> policies may not be appropriate for my application.  I think that the
> "library" vs. "pluggable application" distinction is valid here:   
> maybe
> you want to define an entry point in the egg which a given  
> pluggable app
> would use at startup time to configure all the plugins which exposed
> that entry point.

This probably an indication that there are two (I know, that horrible  
number) types of packages:

  - packages which provide zcml sugar in the form of new directive  
definitions

  - packages which perform component registrations

It seems that packages which do only the former could be classified  
as a "true" library while the latter is more application-y.  It seems  
like in a perfect world, libraries should not need any  
configure.zcml, just a meta.zcml which contains little except meta  
directives.

Personally I think it would be more useful to remove policy-laden  
registrations from existing packages so they're more libraryish and  
move these registrations into "site.zcml" (or an entry point moral  
equivalent) than it would be to attempt to annoint the status quo as  
the right thing by implementing dependency graph traversal.

- C