Add to an XML File

update_xml_file.rb

def update_xml_file(string_to_add, file)
  # Ready a formatted string and XML'ify it
  new_xml = Nokogiri::XML::DocumentFragment.parse(string_to_add)
  # Open the XML file to which we add
  @xml_file = Nokogiri::XML(File.read(file))
  # Find the last instance of the `here` node
  @insertion_point = @xml_file.css('here').last
  # Stick the XML'ified string after the last 'here' node
  @insertion_point.add_next_sibling(new_xml)
  # Save it all
  File.open(file, 'w') { |f| f.write(@xml_file.to_xml) }
end