DataMapper embedded document for mongodb

embedded_coument.rb

module DataMapper
  class Property
    class EmbeddedDocument < Property
      coercion_method nil

      dump_as Hash

      accept_options :document_class

    protected
      def initialize(model, name, options = {})
        super

        @document_class = @options.fetch(:document_class) { raise ArgumentError,'missing :document_class' }

        @load_as = @document_class
      end

    public

      def load(value)
        if value.nil?
          nil
        else
          @document_class.datamapper_load value
        end
      end

      def typecast(value)
        case value
        when @document_class
          value
        when NilClass
          nil
        else
          raise ArgumentError,"+value+ must be of kind #{@document_class} or nil was: #{value.class}"
        end
      end

      def dump(value)
        if value.nil?
          nil
        else
          @document_class.datamapper_dump value
        end
      end
    end
  end
end