active_record_from_xml_fix.rb

# fixes deserialization from xml with nested associations 
# based on http://www.xcombinator.com/2008/08/11/activerecord-from_xml-and-from_json-part-2/

module ActiveRecord #:nodoc:
  module Serialization
 
    def from_hash( hash )
      h = hash.dup
      h.each do |key,value|
        case value.class.to_s
        when 'Array' #collection
          self.send(key).map! { |e| self.class.reflect_on_association(key.to_sym ).klass.new.from_hash e }
        when /\AHash(WithIndifferentAccess)?\Z/ #single object
          if self.send(key).nil? #new object
            self.send("#{key}=", self.class.reflect_on_association(key.to_sym).klass.new.from_hash(value))
          else #existing object
            self.send(key).from_hash(value)
          end
        else
          self.send("#{key}=", value)
        end
      end
      self
    end
 
    def from_json( json )
      from_hash safe_json_decode( json )
    end
 
    # The xml has a surrounding class tag (e.g. ship-to),
    # but the hash has no counterpart (e.g. 'ship_to' => {} )
    def from_xml( xml )
      from_hash begin
        Hash.from_xml(xml).values.first
      rescue ; {} end
    end
 
  end # class Base
end # module ActiveRecord
 
### Global functions ###
 
# JSON.decode, or return {} if anything goes wrong.
  def safe_json_decode( json )
    return {} if !json
    begin
      ActiveSupport::JSON.decode json
    rescue ; {} 
  end
end