47 lines
1.3 KiB
Ruby
47 lines
1.3 KiB
Ruby
# 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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def self.#{name}
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if defined?(@#{name})
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@#{name}
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elsif superclass < #{class_name_to_stop_searching_on} && superclass.respond_to?(:#{name})
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superclass.#{name}
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end
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end
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def #{name}
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self.class.#{name}
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end
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def self.#{name}?
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!!#{name}
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end
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def #{name}?
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!!#{name}
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end
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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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def self.#{name}=(value)
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@#{name} = value
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end
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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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end
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