Rails - May 2006 - Introspection of validates_presence_of

Hello all.

I don''t know how to get all symbols passed to method
validates_presence_of in model. I''ve trying to use following solution:

class News < ActiveRecord::Base
  validates_presence_of :title, :text

  def validates_presence_of(*attr_names)
    @@obligatory_fields = attr_names
    ActiveRecord::Base.validates_presence_of(*attr_names)
  end

  def obligatory_fields
    @@obligatory_fields
  end
end

But when object news was created i''ve got following error message:

uninitialized class variable @@obligatory_fields in News.

I don''t understand when object News call methods:
validates_presence_of, attr_accessible, attr_reader, etc.
Maybe someone know how to deal with this problem?

-- 
 Serhiy Boiko, CRIS-UANIC

On 5/18/06, ?????? ????? <cris@univ.kiev.ua>
wrote:
> class News < ActiveRecord::Base
>   validates_presence_of :title, :text
>
>   def validates_presence_of(*attr_names)
>     @@obligatory_fields = attr_names
>     ActiveRecord::Base.validates_presence_of(*attr_names)
>   end
>
>   def obligatory_fields
>     @@obligatory_fields
>   end
> end
Try:

class News < ActiveRecord::Base
  def self.validates_presence_of(*attr_names)
    @@obligatory_fields = attr_names
    super(*attr_names)
  end

  validates_presence_of :title, :text
  cattr_accessor :obligatory_fields
end