require 'glimmer/error' module Glimmer module DataBinding module Observable # TODO rename methods to observe/unobserve def add_observer(observer, property_or_properties=nil) raise Error, 'Not implemented!' end def remove_observer(observer, property_or_properties=nil) raise Error, 'Not implemented!' end # Overriding inspect to avoid printing very long observer hierarchies def inspect "#<#{self.class.name}:0x#{self.hash.to_s(16)}>" end end end end