Page Comparison

...

Permalink.on_generate do |obj,url_for_obj|
  if obj.is_a? MediaObject
    return "http://permalinkresolver.example.edu/media/#{obj.pid}"
  else
    return nil
  end
end

It's also possible to use a generic route for permalinks.  The pid for an object can be substituted into the object controller route (i.e. /object/avalon:1).  The controller will redirect the browser to the resource.

Permalink.on_generate do |obj,url_for_obj|
  if obj.is_a? MediaObject
    return "http://permalinkresolver.example.edu/object/#{obj.pid}"
  else
    return nil
  end
end