Rails - Aug 2006 - ActiveRecord inheritance with types table

I have a Field class:

  class Field < ActiveRecord::Base
    belongs_to :field_type
  end

with it''s table:
fields:
  id
  field_type_id
  name
  ordering

every field has a type

  class FieldType < ActiveRecord::Base
  end

stored in the field_types table
field_types:
  id
  name
  class_name

for each field type, there''s a subclass of Field that do whatever 
special things

  class BooleanField < Field
    def get_stuff
      return "I am a Boolen Field!"
    end
  end

Is there any way, when I do Field.find(), that I can return fields that 
are all instances of the proper Field subclasses?

I know this could be done using single table inheritance, but I like to 
have the classes in a seperate types table and use foreign keys to to 
ensure there are no invalid types. I also expect to have 10-20 different 
types, all with different attributes that need to be stored in the 
database, so I''d rather not add 20 columns to the fields table. I would
rather store the attributes as name-value pairs in a seperate table. Any 
ideas would be greatly appreciated.

-- 
Posted via http://www.ruby-forum.com/.