2007-12-21 08:48:59 +01:00
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# These class attributes behave something like the class
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# inheritable accessors. But instead of copying the hash over at
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# the time the subclass is first defined, the accessors simply
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# delegate to their superclass unless they have been given a
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# specific value. This stops the strange situation where values
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# set after class definition don't get applied to subclasses.
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class Class
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def superclass_delegating_reader(*names)
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class_name_to_stop_searching_on = self.superclass.name.blank? ? "Object" : self.superclass.name
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names.each do |name|
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class_eval <<-EOS
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2009-02-04 21:26:08 +01:00
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def self.#{name} # def self.only_reader
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if defined?(@#{name}) # if defined?(@only_reader)
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@#{name} # @only_reader
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elsif superclass < #{class_name_to_stop_searching_on} && # elsif superclass < Object &&
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superclass.respond_to?(:#{name}) # superclass.respond_to?(:only_reader)
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superclass.#{name} # superclass.only_reader
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end # end
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end # end
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def #{name} # def only_reader
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self.class.#{name} # self.class.only_reader
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end # end
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def self.#{name}? # def self.only_reader?
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!!#{name} # !!only_reader
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end # end
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def #{name}? # def only_reader?
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!!#{name} # !!only_reader
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end # end
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2007-12-21 08:48:59 +01:00
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EOS
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end
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end
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def superclass_delegating_writer(*names)
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names.each do |name|
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class_eval <<-EOS
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2009-02-04 21:26:08 +01:00
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def self.#{name}=(value) # def self.only_writer=(value)
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@#{name} = value # @only_writer = value
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end # end
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2007-12-21 08:48:59 +01:00
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EOS
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end
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end
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def superclass_delegating_accessor(*names)
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superclass_delegating_reader(*names)
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superclass_delegating_writer(*names)
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end
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2008-05-18 06:22:34 +02:00
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end
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