superclass=
type=module
library=observer
extended=
included=

=== Ū
Mix-in ˤ observer ѥ󶡤ޤ

Observable ⥸塼 include 饹
Observable#changed ᥽åɤˤ깹ե饰Ωơ
Observable#notify_observers ƤӽФ
ե饰ΩäƤϥ֥ФΤޤ
(֥Ф update ᥽åɤƤӽФ)
Observable#notify_observers ΰ
Τޤޥ֥Ф update ᥽åɤϤޤ

=== ץ륳
  require 'observer'
  class AObservable
    include Observable
    ...
  end
  class AObserver
    def update(arg)
      ...
    end
    ...
  end
  obj = AObservable.new
  observer = AObserver.new
  obj.add_observer(observer)
  obj.changed
  obj.notify_observers(args)
