Directory structure to xml - display in flex tree

Below code can be used to convert directory structure in xml.

require 'rubygems'
require 'rexml/document'

class DirectoryStructure
@@excludes = ["..","."]
@@doc = REXML::Document.new %{ <?xml version="1.0" encoding="UTF-8" ?> }

def self.traverse_directory(root_path)

  #traverse initial directory structure
  folder = @@doc.add_element( 'myroot',{'id' => root_path} )

  #call loop_path with root_path and parent_node
  loop_path(root_path,folder)
  #create xml file
   open( "final_directory_structure.xml", "w" ) do |f|
    f.puts @@doc
  end

end

def self.loop_path(path,parent_node)

dir_entries= Dir.entries(path)

# don't need '.','..'
dir_entries = dir_entries-['.','..']

dir_entries.each do | entry |

# check if directory or file
if File.directory?(path+"/"+entry)

   #Folders Loop -------------------------------------------------
   #Gets the directories of the current node.
   #It changes for each recursive call
   folder = parent_node.add_element( 'folder' ,{'label' =>entry
,'file_path' => path+"/"+entry } )
   loop_path( path+"/"+entry, folder )
else
   #Files Loop ------------------------------------------------------
   file = parent_node.add_element( 'file' ,{'label' =>entry ,'file_path'
=> path+"/"+entry } )

end

end

end

#first call to traverse directory
self.traverse_directory("Authentication/Authentication")

end