property_with_fallback.rb

# This is just a dummy example of a property with a "fallback" mechanism
# that an adapter should use if it doesn't know how to natively persist
# a property value.
#
# In this case we're dealing with an array that some datastores can persist
# and others need to call dump before persisting and load after retrieving 
# a property value.

module DataMapper
  class Property
    class Array < Object
      primitive   ::Array
      fallback_to ::String

      def dump(value)
        value.join(',')
      end

      def load(value)
        value.split(',')
      end
    end
  end
end