Making objects to XML with Rubys' reflection (still wip)

xmler.rb

# Author::Simon Symeonidis 
#  This is a funky way to produce xml from a very simple object
#  with very simple instance variables. I was particularly amused
#  with the 'send' function since many times in OOP, we say that 
#  the objects are sending messages to each other; however in this
#  case it's quite literal. 
#
#  If for some reason you want to use this dumb script to check it
#  out, it's very simple. Just create a class Person with instance
#  variables 'name', and 'surname' and include the module in the 
#  class (so inside the class, add 'include XMLer'). Once your object
#  has been initialized, call to_xml, and you should have some output.
#
#  Here's some sample output: 
#  <Person>
#    <name>John</name>
#    <surname>Smith</surname>
#    <age>32</age>
#  </Person>
#
module XMLer

  XMLVersionTag = '<?xml version="1.0"?>'

  def to_xml
    vars = self.instance_variables
    
    # in:  [:@var1, :@var2] 
    # out: [:var1, :var2]
    vars.each_with_index do |val,index| 
      vars[index] = val.to_s.gsub('@','').to_sym
    end 

    output = XMLVersionTag
    output += "<#{self.class.name}>"
    vars.each do |val| 
      case self.send(val).class.name
      when "Array"
        output += process_a(val)
      
      when "Hash"
        output += process_h(val)

      when "Fixnum"
        output += process_i(val)  
 
      when "String"
        output += "<#{val}>"
	output += self.send(val)
	output += "</#{val}>"
      end 
      
    end 
    output += "</#{self.class.name}>"

  end 

private 

  def process_i(val)
    process_simple(val)
  end 


  def process_simple(val)
    ret = "<#{val}>"
    ret += "#{self.send(val)}"
    ret += "</#{val}>"
  end

  def process_a(val)
    ret = String.new
    ret += "<#{val}>"
    self.send(val).each do |el|
      ret += "<#{el}/>"
    end
    ret += "</#{val}>"
    return ret
  end 

  def process_h(val)
    ret = String.new 
    ret += "<#{val}>"
    self.send(val).each_pair do |key,value| 
      ret += "<#{key}>"
      case value.class.name
      when "Array"
        ret += process_a(value)
      
      when "Hash"
        ret += process_h(value)

      when "Fixnum"
        ret += process_i(value)  
 
      when "String"
	ret += value

      end 
        ret += "</#{key}>"

    end 
    ret += "</#{val}>"
    return ret 
  end 

end