Create XPath from XML node structure

make_xpath.rb

def make_xpath(node, xpath = "//")
  xpath << node.name

  first = true

  node.attributes.values.each do |attr|
    if first
      first = false
      xpath << "["
    else
      xpath << " and "
    end

    xpath << "@" << attr.name << ' = "' << attr.value << '"'
  end

  node.children.each do |ch|
    if ch.elem?
      if first
        first = false
        xpath << "["
      else
        xpath << " and "
      end
      
      make_xpath(ch, xpath) 
    end
  end

  xpath << "]" unless first

  xpath
end