Hack for ActiveRecord: to avoid "NameError: uninitialized constant" on Rails-3.1.3 + active_scaffold 3.* (append parent module name to association's class_name)

activerecord_hack__association_auto_class_name_with_parent_module.rb

class ActiveRecord::Reflection::AssociationReflection
  def derive_class_name
    cn = ""
    parent = active_record.parent
    unless parent == Object
      cn << "#{parent.name}::"
    end
    cn << name.to_s.camelize
    cn = cn.singularize if collection?
    cn
  end
end

"NameError: uninitialized constant" on Rails-3.1.3 + active_scaffold 3.*": https://gist.github.com/1663895