ActiveModel Object With Multi-Part Attribute/Date Support

Simple Ruby ActiveModel class that works with View and Form helpers in Rails 3. Appears to handle dates properly. Let me know if any problems arise:

class CreditCard
  include ActiveModel::Validations
  include ActiveModel::Conversion
  extend ActiveModel::Naming    

  attr_accessor :name
  attr_accessor :number
  attr_accessor :expiration_date
  attr_accessor :code
  
  validates_presence_of [ :name, :number, :expiration_date, :validation_code ]
  validates_format_of :number, :with => /^\d+$/, :if => Proc.new {|o| !o.card_number.blank? && !o.errors[:card_number] }
  validates_format_of :code, :with => /^\d+$/, :if => Proc.new {|o| !o.code.blank? && !o.errors[:code] }
  
  def initialize( attrs = {} )
    if !attrs.nil? then
      dattrs = {}
      attrs.each do |n, v|
        if n.match( /^(.+)\(.+\)$/ ) then
          an = Regexp.last_match[1]
          dattrs[an] = [] if dattrs[an].nil?
          dattrs[an] << { :n => n, :v => v }
        else
          send( "#{n}=", v)          
        end          
      end
      dattrs.each do |k, v|
        vs = v.sort_by{|hv| hv[:n] }.collect{|hv| hv[:v] }
        p1 = vs[0]
        p2 = ( vs[1].size() > 0 ? ( vs[1].size() == 1 ? "0#{vs[1]}" : vs[1] ) : "01" )
        p3 = ( vs[2].size() > 0 ? ( vs[2].size() == 1 ? "0#{vs[2]}" : vs[2] ) : "01" )
        dv = [ p1, p2, p3 ].join( "-" )
        begin send( "#{k}=", Date.parse( dv ) ); rescue; end
      end
    end        
  end
  
  def persisted?
    false
  end
  
end