Sample Code for ROXML Text Node Factory

roxml_examples_01.rb

require 'rubygems'
require 'roxml'

xml = '
<library>
   <name>Fullerton Public</name>
   <phoneNumber>000-000-000</phoneNumber>
   <media>
     <item>
        <medium>cassette-tape</medium>
        <title>The Story About Ping</title> 
        <readBy>A. Reader</readBy>
     </item>
     <item>
        <medium>book</medium>
        <title>The Story About Ping</title> 
        <binding>hardcover</binding>
     </item>
   </media>
</library>
'

class Library
  include ROXML

  xml_convention do |s|
    c = s.camelcase
    c[0..0].to_s.downcase + c[1..-1].to_s
  end
  
  xml_accessor :name
  xml_accessor :phone_number
end

lib = Library.from_xml( xml ) # pass an IO or String containing the XML
puts lib.to_xml

class Book
  include ROXML
  xml_accessor :title
  xml_accessor :author
end
 
class Library
  xml_accessor :books, :in   => :books, 
                       :as   => [Book]
end

lib = Library.new
lib.name = 'Fullerton Public'
lib.books = []

a_book = Book.new
a_book.title  = 'The Story About Ping'
a_book.author = 'Marjorie Flack'

lib.books << a_book

puts lib.to_xml

puts Library.from_xml( lib.to_xml.to_s ).books.first.title

class Medium

  include ROXML
  
  class << self

    def register(medium_id = nil, a_class = self)
      registry.store(medium_id || id_from_class, a_class)
    end

    def id_from_class
      demod       = ActiveSupport::Inflector.demodulize(self.name)
      underscored = ActiveSupport::Inflector.underscore(demod)
      dasherized  = ActiveSupport::Inflector.dasherize(underscored)
    end

    def class_for(medium_id)
      registry[medium_id]
    end

    def registry
      unless Medium.instance_variable_defined?(:@registry)
        Medium.instance_variable_set(:@registry, { })
      end
      Medium.instance_variable_get(:@registry)
    end

    private :registry

    alias __original_from_xml from_xml

    def from_xml(xml, *args)
      if self == Medium
        xml_node = ROXML::XML::Node.from(xml)
        if xml_node.nil?
          raise "Bad xml for action:\n\t#{xml}"
        end
        medium_id = xml_node.xpath('medium').first.text.strip
        medium_class = @registry[medium_id] if defined?(@registry)
        unless medium_class.nil?
          medium_class.from_xml(xml_node, *args)
        else
          $stderr.puts "WARN: no medium for #{medium_id}."
          __original_from_xml(xml, *args)
        end
      else
        __original_from_xml(xml, *args)
      end
    end

  end  # class methods

  xml_name 'medium' # even in subclasses
  
  xml_convention do |s|
    c = s.camelcase
    c[0..0].to_s.downcase + c[1..-1].to_s
  end
  
  xml_accessor :title
  xml_accessor :author
end

class CassetteTape < Medium
  xml_accessor :read_by
end

self.class.send(:remove_const, :Book )

class Book < Medium
  xml_accessor :binding
end

class Library
 
  xml_accessor :media, 
               :from => 'item',
               :in   => 'media',
               :as   => [Medium]
end

CassetteTape.register
Book.register

puts Medium.send(:registry).inspect

lib = Library.from_xml(xml)
lib.media.each do |item|
  puts "#{item.title} (#{item.class})"
end