Address all or nothing validation

address_all_or_nothing.rb

class Address < ActiveRecord::Base
  attr_accessible :address1, :address2, :phone, :city, :state, :zip, :country, :website_url, :name

  def validate
    required_set = [:address1, :city, :state, :zip, :country]
    matches = required_set.map {|my_method| self.send(my_method).present? }.reduce(0) {|a,b| a + (b == true ? 1 : 0) }
    self.errors.add(:address1, "Must have a full address!") if matches.between?(1, 4)
  end

end