Difficulty parsing gpx file with libxml-ruby

[mrampton]

Hey guys,

I'm hoping that someone with more xml experience can see the easy explanation as to why i'm having difficulties here. Basically I'm attempting to extract elements from a gpx file (xml file for gps data). I had this working in rexml but it was TERRIBLY slow.

And, I can actually get it working if I muck with the gpx file and delete some of the urls in the header (for the xmlns variables).

Anyway, here's my model code and an example of the gpx file that it won't parse. No error messages appear -- it seems to simply skip right over the loop that cycles through the xml file.

require 'rubygems'
require 'xml/libxml'

class Path < ActiveRecord::Base
    has_many :geocodes
    belongs_to :trail

    def readGPX(file)
       
    if File.exist?("#{RAILS_ROOT}/gpxfiles/#{file}")
      puts "#{RAILS_ROOT}/gpxfiles/#{file}"
      gpxfile = File.new("#{RAILS_ROOT}/gpxfiles/#{file}")
     
    end
   
    doc = XML::Document.file("#{RAILS_ROOT}/gpxfiles/#{file}")
    root = doc.root
    puts "Root element name: #{root.name}"
    puts root

    puts "im stuck outside"
    doc.find('//gpx/trk/trkseg/trkpt').each do |node|
      # puts "Node path: #{node.path} \t Contents: #{node.content}"
      puts "Im inside at least"
    end
    puts "im back outside"

# NOTE: only the outside puts are printed. no error messages either...

    # from our regxml days... this parses fine
    # doc.elements.each("gpx/trk/trkseg/trkpt") { |element|
    #   g = Geocode.new
    #   g.longitude = element.attributes["lon"]
    #   g.latitude   = element.attributes["lat"]
    #   g.save 
    #   geocodes << g
    # }

  end
end

------------
gpx snippet (cutting and pasting might screw the with the format - sorry if it's hard to read).
------------

<gpx xmlns="[URL unfurl="true"]http://www.topografix.com/GPX/1/0[/URL] " xmlns:xsi="[URL unfurl="true"]http://www.w3.org/2001[/URL]
/XMLSchema-instance" xmlns:mbx="[URL unfurl="true"]http://www.motionbased.net/mbx"[/URL] xsi:schemaLocati
on="[URL unfurl="true"]http://www.topografix.com/GPX/1/0[/URL] [URL unfurl="true"]http://www.topografix.com/GPX/1/0/gpx.xsd[/URL]
[URL unfurl="true"]http://www.motionbased.net/mbx[/URL] [URL unfurl="true"]http://www.motionbased.net/site/schemas/mbx/0.0.1[/URL]
/mbx.xsd" creator="MotionBased Technolgies [URL unfurl="true"]http://www.motionbased.com[/URL] " version="
1.0">
  <trk>
    <mbx:gpsTrackPk>610018</mbx:gpsTrackPk>
    <trkseg>
      <trkpt lat="37.71365" lon="-122.099394">
        <ele>90.0</ele>
        <time>2006-02-12T10:02:49-08:00</time>
        <course>180.00000500895632</course>
        <speed>0.38016656041145325</speed>
      </trkpt>
    </trkseg>
  </trk>
</gpx>

--------
AND ...
--------

The above will parse if I delete the xmlns= section to produce the following gpx tag

<gpx xsi:schemaLocati
on="[URL unfurl="true"]http://www.topografix.com/GPX/1/0[/URL] [URL unfurl="true"]http://www.topografix.com/GPX/1/0/gpx.xsd[/URL]
[URL unfurl="true"]http://www.motionbased.net/mbx[/URL] [URL unfurl="true"]http://www.motionbased.net/site/schemas/mbx/0.0.1[/URL]
/mbx.xsd" creator="MotionBased Technolgies [URL unfurl="true"]http://www.motionbased.com[/URL] " version="
1.0">