phone_field.rb

module PhoneField
  def phone_field(field_name)
    define_method :"#{field_name}=" do |content|
      self[field_name.to_s] = self.class.strip_nonnumeric content
    end
    
    define_method :"formatted_#{field_name}" do
      raw = send field_name
      raw.blank? ? '' : "(#{raw[0..2]}) #{raw[3..5]}-#{raw[6..9]}"
    end
    
    validates_format_of field_name, :with => /[0-9]{10}/, :allow_blank => true
    validates_uniqueness_of field_name, :allow_blank => true
  end
  
  def phone_fields(*field_names)
    field_names.each {|p| phone_field p}
  end

  def strip_nonnumeric(phone)
    (phone || '').gsub /[^0-9]/, ''
  end
end