cms-resources.rb

class ResourceGroup
  has_many :resource_entries
end

class ResourceEntry
  belongs_to :resource, :polymorphic => true
end

# A type of resource
class Image < ActiveRecord::Base
  has_one :resource_entry, :as => :resource
end

# A type of resource
class Document < ActiveRecord::Base
  has_one :resource_entry, :as => :resource
end

# A type of resource
class Link < ActiveRecord::Base
  has_one :resource_entry, :as => :resource
end