require 'rexml/document'
require 'rexml/streamlistener'

class MyListener
  include REXML::StreamListener
  def tag_start(*args)
    puts "tag_start: #{args.map {|x| x.inspect}.join(', ')}"
  end
  def text(data)
    return if data =~ /^\w*$/ # whitespace only
    puts " text: #{data}"
  end
end

list = MyListener.new
xmlfile = File.new("data.xml")
REXML::Document.parse_stream(xmlfile, list)