From: altinsel <altinsel@...>
Date: 2008-09-16T04:32:45+09:00
Subject: ruby / rexml / xpath bug?


I'm doing something I would think is very straight-forward but am
getting the strangest result.  I'm wondering if anyone could help to
let me know if this is a bug or if I'm doing something I can't see..

I copied a Google Maps script from Google Maps with Rails and Ajax
straight from code.  It requests a geocoding from Google and parses
the XML using rexml.  When it gets to the address with 2 results, the
"each" iterator is looping through, but on the second element is
giving me info from the first.  below is the script exactly.

require 'open-uri'
require 'rexml/document'

# Retrieve geocode information for all records in the Stores table
task :google_geocode => :environment do
  api_key=GOOGLE_MAPS_KEY

    (Store.find :all).each do |store|

      puts "\nStore: #{store.name}"
      puts "Source Address: #{store.full_address}"

      xml=open("http://maps.google.com/maps/geo?
q=#{CGI.escape(store.full_address)}&output=xml&key=#{api_key}").read
      doc=REXML::Document.new(xml)

      puts "Status: "+doc.elements['//kml/Response/Status/code'].text

      if doc.elements['//kml/Response/Status/code'].text != '200'
        puts "Unable to parse Google response for #{store.name}"
      else
        doc.root.each_element('//Response') do |response|
          response.each_element('//Placemark') do |place|
            #there are 2 "Placemarks" in one particular "Response"
            lng,lat=place.elements['Point/
coordinates'].text.split(',')
            puts "  Result Address: " << place.elements['//
address'].text
            # the address, lat and lng come from the 1st element twice
            puts "  ID: " << place.attributes['id']
            # .. but the 'id' is correct.
            puts "  Latitude: #{lat}"
            puts "  Longitude: #{lng}"
          end # end each place
        end # end each response
      end # end if result == 200
    end # end each store
  end # end rake task

#####

What I don't understand, is that the XML for each "place" is correct,
but the place.elements['//address'] keeps finding the previous
iterations information. How can this be?

Thank you.