error.xml

<?xml version="1.0" encoding="utf-8"?>
<rsp stat="fail">
  <err code="11" msg="Something bad happened" />
</rsp>

gistfile2.rb

require 'rubygems'
require 'happymapper'
require 'pp'

class Error
  include HappyMapper

  attribute :code, Integer
  attribute :message, String
end

class Rsp
  include HappyMapper

  # NOTE: tag "/rsp" helps, but doesn't seem necessary
  attribute :stat,  String
  element   :err, Error
end


error = File.read("error.xml")
pp Rsp.parse(error) # => []
pp Rsp.parse(error, :single => true) # => nil