to_plist.rb

---- config/initializers/to_plist.rb

require 'rails_extensions/plist'

ActiveRecord::Base.class_eval do
  include Plist
end




---- rails_extensions/plist.rb
module Plist
  
  def to_plist(options = {})
    hash = ActiveRecord::Serialization::Serializer.new(self, options).serializable_record
#    hash.to_plist
    PlistXmlSerializer.new(hash, options).serialize
  end
  
  class PlistXmlSerializer

    attr_reader :options

    def initialize(record, options = nil)
      @record = record
      @options = options ? options.dup : {}
    end

    def builder
      @builder ||= begin
        options[:indent] ||= 2
        builder = options[:builder] ||= Builder::XmlMarkup.new(:indent => options[:indent])
        unless options[:skip_instruct]
          builder.instruct!
          builder.declare!(:DOCTYPE, :plist, :PUBLIC, "-//Apple//DTD PLIST 1.0//EN", "http://www.apple.com/DTDs/PropertyList-1.0.dtd" )
          options[:skip_instruct] = true
        end
        builder
      end
    end

    def serialize
      if options[:do_not_add_version]
        build_attributes
      else
        builder.plist(:version => "1.0" ) do
          build_attributes
        end
      end
    end

    def build_attributes
      builder.dict do
        @record.each do |k, v|
        builder.key k.to_s
          case v
            # weird v.class doesn't work, but plain old v does
          when String
            builder.string v
          when Time
            builder.date v.strftime('%Y-%m-%dT%H:%M:%SZ')
          when Fixnum
            builder.integer v
          when BigDecimal
            builder.real v
          when FalseClass
            builder.false
          when TrueClass
            builder.true
          else
            builder.string v
          end
        end
      end
    end

    # xml.comment!("COMMENT")
    # xml.declare!("DECLARATION")
    # xml.cdata!("CDATA")

    # def to_s
    #   serialize
    # end

    # def to_plist(options = {:root => 'dict'})
    #   options[:indent] ||= 2
    #   xml = options[:builder] ||= Builder::XmlMarkup.new(:indent => options[:indent])
    #   unless options[:skip_instruct]    
    #     xml.instruct! 
    #     xml.declare!(%w{DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"} )
    #     xml.plist(:version => "1.0" ) do
    #       xml.dict do
    #         self.attributes.each do |k, v|
    #           xml.key k.to_s
    #           xml.string v.to_s
    #         end
    #       end
    #     end
    #   end
    # end

    # module Enumerable
    #   def to_plist(*a)
    #     to_a.to_plist(*a)
    #   end
    # end

  end
  
end

class Array
  
  def to_plist(options = {})
    raise "Not all elements respond to to_plist" unless all? { |e| e.respond_to? :to_plist }
    require 'builder' unless defined?(Builder)

    options = options.dup
    options[:root]     ||= all? { |e| e.is_a?(first.class) && first.class.to_s != "Hash" } ? ActiveSupport::Inflector.pluralize(ActiveSupport::Inflector.underscore(first.class.name)) : "records"
    options[:children] ||= options[:root].singularize
    options[:indent]   ||= 2
    options[:builder]  ||= Builder::XmlMarkup.new(:indent => options[:indent])

    root     = options.delete(:root).to_s
    children = options.delete(:children)

    if !options.has_key?(:dasherize) || options[:dasherize]
      root = root.dasherize
    end
    
    unless options.delete(:skip_instruct)
      options[:builder].instruct! 
      options[:builder].declare!(:DOCTYPE, :plist, :PUBLIC, "-//Apple//DTD PLIST 1.0//EN", "http://www.apple.com/DTDs/PropertyList-1.0.dtd" )
    end

    opts = options.merge({ :root => children })
    
    plist = options[:builder]
      # yield plist if block_given?    
    plist.plist(:version => "1.0" ) do
      if options[:hash]
        plist.tag!('dict') do
          each do |e| 
            plist.key e.id
            e.to_plist(opts.merge({ :skip_instruct => true, :do_not_add_version => true }))
          end
        end
      else
        plist.tag!('array') do 
          each { |e| e.to_plist(opts.merge({ :skip_instruct => true, :do_not_add_version => true })) }
        end
      end
    end
    plist.target!
  end
  
end