delegate_model_attributes.rb

class ProductData < ActiveRecord::Base
  belongs_to :product

  def self.attribute_column_names
    return @@attr_columns if defined?(@@attr_columns)
    readers = content_columns.map { |n| n.name.intern } - [:created_at,:updated_at]
    @@attr_columns ||= readers.map { |k| [k, "#{k}=".to_sym] }.flatten
  end
end


class Product < ActiveRecord::Base
  has_one :product_data
  accepts_nested_attributes_for :product_data

  delegate( *ProductData.attribute_column_names << {:to => :product} )

  def initialize(*args)
    super(*args)
    build_product_data if product_data.nil?
  end
end

delegate_polymorphic_model_attributes.rb

class Address < ActiveRecord::Base
  belongs_to :addressable, :polymorphic => true

  def self.attribute_column_names
    return @@attr_columns if defined?(@@attr_columns)
    readers = content_columns.map { |n| n.name.intern } - [:addressable_type,:created_at,:updated_at]
    @@attr_columns ||= readers.map { |k| [k, "#{k}=".to_sym] }.flatten
  end
end


class User < ActiveRecord::Base
  has_one :address, :as => :addressable, :dependent => :destroy

  accepts_nested_attributes_for :address
  delegate( *Address.attribute_column_names << {:to => :address, :prefix => :address} )
end

#>> u = User.new
#=> #<User id: nil, store_id: nil, login: nil, email: nil, name: nil, role: "guest", state: "pending", group_id: nil, crypted_password: nil, password_salt: nil, persistence_token: nil, perishable_token: nil, login_count: nil, last_request_at: nil, last_login_at: nil, current_login_at: nil, last_login_ip: nil, current_login_ip: nil, created_at: nil, updated_at: nil, phone: nil>
#>> u.address.is_a? Address
#=> true
#>> u.methods.select { |m| m =~ /address/ }
#=> ["address", "address=", "loaded_address?", "set_address_target", "create_address", "has_one_dependent_destroy_for_address", "build_address", "autosave_associated_records_for_address", "validate_associated_records_for_address", "address_addressee", "address_addressee=", "address_attributes=", "address_line_1", "address_line_1=", "address_line_2", "address_line_2=", "address_city", "address_city=", "address_region", "address_region=", "address_country", "address_country=", "name_with_email_address", "address_postal_code", "address_postal_code="]
#>> u.address_line_1
#=> nil
#>> u.address_line_1 = "123 Main"
#=> "123 Main"
#>> u.address.line_1
#=> "123 Main"