inheritance.rb

gistfile1.txt

    module ClassMethods
      # True if this isn't a concrete subclass needing a STI type condition.
      def descends_from_active_record?
        if superclass.abstract_class?
          superclass.descends_from_active_record?
        else
          superclass == Base || !columns_hash.include?(inheritance_column)
        end 
      end 

      def finder_needs_type_condition? #:nodoc:
        # This is like this because benchmarking justifies the strange :false stuff
        :true == (@finder_needs_type_condition ||= descends_from_active_record? ? :false : :true)
      end 

      def symbolized_base_class
        @symbolized_base_class ||= base_class.to_s.to_sym
      end 

      def symbolized_sti_name
        @symbolized_sti_name ||= sti_name.present? ? sti_name.to_sym : symbolized_base_class
      end 

      # Returns the base AR subclass that this class descends from. If A
      # extends AR::Base, A.base_class will return A. If B descends from A
      # through some arbitrarily deep hierarchy, B.base_class will return A.
      #   
      # If B < A and C < B and if A is an abstract_class then both B.base_class
      # and C.base_class would return B as the answer since A is an abstract_class.
      def base_class
        class_of_active_record_descendant(self)
      end 
      
      #....
    end