Tidy XML with Ruby

tidy_helper.rb

module TidyHelper                                                                                                                                                                                                                                                                                                             
  def self.tidy_xml xml_string                                                                                                                                                                                                                                                                                                
    IO.popen("tidy -q --input-xml y --output-xml y --indent 'auto' --indent-attributes y --indent-spaces '4' --wrap '90'", "w+") do |pipe|                                                                                                                                                                                    
      buffer = String.new                                                                                                                                                                                                                                                                                                     
      pipe.puts xml_string                                                                                                                                                                                                                                                                                                    
      pipe.close_write                                                                                                                                                                                                                                                                                                        
      while line = pipe.gets                                                                                                                                                                                                                                                                                                  
        buffer << line                                                                                                                                                                                                                                                                                                        
      end                                                                                                                                                                                                                                                                                                                     
      buffer                                                                                                                                                                                                                                                                                                                  
    end                                                                                                                                                                                                                                                                                                                       
  end                                                                                                                                                                                                                                                                                                                         
end