acts_as_ferret extra (polymorphic) fields...

Hi,

I have a class with some polymorphic associations to it. I want to use acts_as_ferret to index my objects and its associations. I want to do it in a way I can define the fields from the associations to be indexed in the association class.

I know I could do something like:

  acts_as_ferret :fields => [:title, :body, :author_name]   has_one :author

  def author_name     author.name   end

but since the relationship is polymorphic it woul be like

  acts_as_ferret :fields => [:title, :body, :extra_field]   belongs_to :extra, :polymorphic=>true

  def extra_field     case self.extra_type       when 'x'         x.name       when 'y'          y.date   end

what is very ugly and realy not DRY. How can I define in the foreing class the fields to be indexed?

thanks for any answers! acts_as_ferret seems to be very nice, but I fell it lacks some docs.

Bruno