21 lines
805 B
Markdown
21 lines
805 B
Markdown
---
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layout: pattern
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title: Decorator
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folder: decorator
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permalink: /patterns/decorator/
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categories: pattern_cat
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tags: pattern_tag
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---
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**Intent:** Attach additional responsibilities to an object dynamically.
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Decorators provide a flexible alternative to subclassing for extending
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functionality.
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**Applicability:** Use Decorator
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* to add responsibilities to individual objects dynamically and transparently, that is, without affecting other objects
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* for responsibilities that can be withdrawn
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* when extension by subclassing is impractical. Sometimes a large number of independent extensions are possible and would produce an explosion of subclasses to support every combination. Or a class definition may be hidden or otherwise unavailable for subclassing
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