gistfile1.xml

<people>
  <person>
    <name>Paul</name>
    <addresses>
      <address>
        <city>Boulder</city>
        <state>Colorado</state>
      </address>
    </addresses>
  </person>
</people>

gistfile2.rbx

class Person
  include DataMapper::Resource

  property :name, String

  has n, :addresses
end

class Address
  include DataMapper::Resource

  property :city,  String
  property :state, String
  
  belongs_to :person
end

gistfile3.rbx

def read_many(query)
  pp query
  Collection.new(query) do |collection|
    @xml.find("/people/person").each do |item|
      person = collection.load(
        query.fields.map do |prop| 
          text_for_elem(item, prop_to_elem(prop))
        end
      )
      a_query = Query.new(query.repository, Address)
      a_collection = Collection.new(a_query) do |a_collection|
        item.find("addresses/address").each do |a_xml|
          a_collection.load(
            a_query.fields.map do |prop|
              text_for_elem(a_xml, prop_to_elem(prop))
            end
          )
        end
      end
      person.send(:addresses_association).instance_variable_set(:@children, a_collection)
    end
  end
end