Decorator Pattern

Status: draft · Confidence: medium (0.635) · Basis: verified_sources

Quality notes: generic_source_homepage, no_verified_sources, partial_source_verification

## TL;DR

Attaches additional responsibilities dynamically, providing flexible alternative to subclassing. Decorators conform to the same interface, enabling transparent stacking.

## Core Explanation

Example: `new CompressedStream(new EncryptedStream(new FileStream()))`. Python @decorator syntax. ES7 decorators (Stage 3). React HOC (Higher-Order Components) is a decorator pattern applied to components. Middleware pattern (Express, Koa) is a variant.

## Further Reading

- [Design Patterns (Gang of Four)](undefined)

## Related Articles

- [Adapter Pattern](../adapter-pattern.md)
- [Command Pattern](../command-pattern.md)
- [Factory Method Pattern](../factory-method-pattern.md)