recursive function to render xml from a multidimensional hash using Nokogiri.

hash to xml

def write_xml(hash)
  builder = Nokogiri::XML::Builder.new do |xml|
    hash_to_xml(hash, xml)
  end
  render xml: builder
end

def hash_to_xml(hash, xml)
  hash.each do |key, value|
    if value.is_a? String
      xml.send(key, value)
    elsif value.is_a? Hash
      xml.send(key.to_s) { hash_to_xml(value, xml) }
    end
  end
  xml
end