Soliciting Feedback: Rearranging ActiveFedora code related to Content Modeling

[Matthew Zumwalt]

Rick has just contributed some new code that extends ActiveFedora in useful ways.  Among other things, he added a has_datastream model method and added the long-absent support for deleting relationships.  Incorporating his code has precipitated some ideas about how to make the code base more readable & maintainable, at least where it is dealing with content modeling stuff.

Currently, the support for content modeling type stuff (has_metadata, has_relationship, etc.) is sprinkled all around in the code base.  I think we should put all of that stuff into a directory called active_fedora/model/ and modify the current ActiveFedora::Model  module to inject all of that content model-derived functionality when you include it in a class.  

At first pass, I'm thinking we should create these files:

active_fedora/model/datastream_modeler.rb

active_fedora/model/relationship_modeler.rb

active_fedora/model/metadata_modeler.rb

These would define ActiveFedora::Model::DatastreamModeler, ActiveFedora::Model::RelationshipModeler, and ActiveFedora::Model::MetadataModeler, which would provide class methods like has_metadata as well as any associated instance methods like metadata_streams.  Then we could add these lines to active_fedora/model.rb:

self.included(klass)  

    klass.send(:include, ActiveFedora::Model:: DatastreamModeler)

    klass.send(:include, ActiveFedora::Model::RelationshipModeler)

    klass.send(:include, ActiveFedora::Model:: MetadataModeler)

end

This would ensure that ActiveFedora::Base will inherit all of those behaviors when it calls "include ActiveFedora::Model" .

We should also start moving in the direction of aligning this work (features & method names) with Fedora's Enhanced Content Models (http://sourceforge.net/apps/mediawiki/ecm/index.php?title=Main_Page) whenever possible.  This will make it easier for us to serialize all of this information into ECM content model objects.

Any thoughts?

Matt Zumwalt

MediaShelf, LLC

http://www.yourmediashelf.com