Datamapper Location object that updates logitude, latitude, city and state based on zip code

location.rb

require 'hpricot'
require 'open-uri'

class Location
  include DataMapper::Resource
  
  before :create, :update_location
  
  property :id, Serial
  property :name, String
  property :email, String
  property :city, String
  property :state, String
  property :zip_code, String
  property :longitude, Float
  property :latitude, Float

  def coordinates=(value)
    self.longitude, self.latitude = value.split(",")
  end
  def coordinates
    "#{self.longitude},#{self.latitude}"
  end

  def self.google_maps_key
    # YOUR GOOGLE MAPS ID HERE
  end
  
  protected
    def update_location
      doc = Hpricot.parse(open("http://maps.google.com/maps/geo?q=#{self.zip_code}&output=xml&key=#{Location.google_maps_key}"))
      self.city = (doc/:localityname)[0].inner_text
      self.state = (doc/:administrativeareaname)[0].inner_text
      self.coordinates = (doc/:coordinates)[0].inner_text
    end
end