View Larger Map

Pretty slick!

#written by Benjamin Smith
#www.disjointthoughts.com
#benjamin.lee.smith@gmail.com

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

#arg: url to parse from http://www.hotspringsenthusiast.com/TextLinks.asp
#doesnt work for arkansas, georgia, new york, north carolina, south dakota, virgina
url = ARGV[0]

#parse name of state out of url
state = url[url.index('.com')+5..url.length-5]

#grab the html
doc = Hpricot(open(url))

#create xml for the kml file
xml = REXML::Document.new
kml = xml.add_element 'kml', {'xmlns' => 'http://earth.google.com/kml/2.1'}
kml_doc = kml.add_element 'Document'

#add the name of the state to the xml
(kml_doc.add_element 'name').text = "#{state} Hot Springs"

#add reference to me
(kml_doc.add_element 'description').text = 'created by Benjamin Smith http://www.disjointthoughts.com'
doc_folder = kml_doc.add_element 'Folder'

#add reference to the data source
(doc_folder.add_element 'name').text = 'http://www.hotspringsenthusiast.com/'
(doc_folder.add_element 'description').text = "data source #{url}"

#iterate over the rows in the table
doc.search('//tr').each do |tr|
  tds = tr.search('//td')
  if tds.first.inner_html != 'STATE'
    link = tds[3].search('//a').to_s
    lat = link[link.index('lat=')+4..link.index('&',link.index('lat='))-1]
    lon = link[link.index('lon=')+4..link.index('"',link.index('lon='))-1].gsub('E','')
    topo = link[link.index('href="')+6..link.index('"',link.index('href="')+7)-1] 

    placemark = doc_folder.add_element 'Placemark'
    (placemark.add_element('name')).text = tds[3].search('//a').inner_html.to_s.gsub("\r\n",'').squeeze.downcase
    (placemark.add_element('description')).text = REXML::CData.new('Temperature: '+tds[4].inner_html+'F/'+tds[5].inner_html+'C<br/><a href="'+topo+'">Topo')
    point = placemark.add_element 'Point'
    (point.add_element 'coordinates').text = "#{lon.to_s},#{lat.to_s}"
  end
end

f = File.new("#{state.downcase}.kml",'w')
f.write(''+"\n")
xml.write(f,4)
f.close

#create html file to display kml in google map
erb = ERB.new(File.read('template_hot_springs.erb'))
f = File.new("#{state.downcase}_hot_springs.html",'w')
f.write(erb.result(binding))
f.close

If you’d like to run it on your own, you can download it here. You’ll also need this template file and this css file.

The map was created using a kml file loaded into an html page using some google javascript magic:


var geoXml = new GGeoXml("http://www.disjointthoughts.com/static_blog_files/arizona.kml");


Everything loaded up and looked fine until I tried to click on one of the markers/pins. When I clicked on the markers, the bubble which appeared over the it was blank instead of containing the description: name of the hot spring along with a link to a topo. To make things more confusing, this behavior didn’t happen when loading the kml in google earth.

Since the kml file worked fine in google earth, I assumed the kml file was ok. The HTML I was using to render the map in a web browser was a copied/pasted example from google’s documentation, so I assumed that was ok as well. After some searching around I found this thread describing my exact problem. Turns out google’s documentation was a bit outdated. The javascript include for google map api needs to be updated from “v=2″ to “v=2.x”:

<script src="http://maps.google.com/maps?file=api&v=2.x&key=your-google-map-key" type="text/javascript"></script>

This cured my problem. Now I have a lovely, marker clickable, map of the hot springs of arizona.