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57 lines
974 B
Ruby
57 lines
974 B
Ruby
# The decorator design pattern allows for features to be added dynamically to an
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# existing object.
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class Decorator
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def initialize(item)
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@item = item
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end
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def use
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item.use
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end
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# Dynamic method that added in decorator
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def another_use
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item.use + "another way"
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end
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end
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class MagicDecorator < Decorator
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def description
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@item.description + "Magic"
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end
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end
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class MasterpieceDecorator < Decorator
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def description
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@item.description + "Masterpiece"
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end
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end
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# Class what should be decorated
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class Item
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attr_reader :description
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def initialize
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@description = "Item "
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end
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def use
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"use it"
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end
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end
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# Usage
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item = Item.new
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puts item.description # => Item
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magic_item = MagicDecorator.new(item)
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puts magic_item.description # => Item Magic
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masterpiece_item = MasterpieceDecorator.new(item)
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puts masterpiece_item.description # => Item Masterpiece
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# All next lines puts "use it"
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item.use
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magic_item.use
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masterpiece_item.use |