Decorator
Attaches additional responsibilities to an object dynamically. Provides a flexible alternative to subclassing for extending functionality.
Decorator: Add Behavior Without Changing the Class
Wrapping an object with new capabilities while keeping the same interface.
Decorator in Production: Middleware and Observability
Decorators for logging, caching, and retries around services.
Advanced Decorator: Dynamic and Transactional Wrapping
Runtime-assembled decorator stacks and transactional wrappers.
Decorator: Review & Mastery Quiz
Scenario questions on wrapping, stacking, and composition.
Free Books & Guides
Refactoring.Guru — Decorator
The definitive modern guide to the Decorator pattern. Clear explanations, UML diagrams, real-world analogies, and code examples in multiple languages.
SourceMaking — Decorator
A comprehensive companion guide covering the Decorator pattern with detailed rules of thumb, criticisms, and robust code snippets.
GoF Design Patterns — Decorator
The original Gang of Four book describing the pattern. Available in the "Design Patterns: Elements of Reusable Object-Oriented Software" on Wikipedia.
Official Documentation
Video Courses
freeCodeCamp — Design Patterns Course
A comprehensive multi-hour video course covering all major design patterns with implementations in JavaScript and TypeScript.
Design Patterns in Modern JavaScript Playlist
YouTube playlist covering creational, structural, and behavioral patterns with clear code walkthroughs.
Web Dev Simplified — Decorator
Clear, concise video tutorials covering design patterns with practical examples.
Practice & Examples
Awesome Low-Level Design (GitHub)
A curated collection of free LLD resources, pattern implementations, and interview problems across multiple languages.
Design Patterns Implementation (GitHub)
The most popular open-source collection of design pattern implementations with detailed explanations.
Refactoring.Guru Examples in Decorator
Code examples of the Decorator pattern in TypeScript, Python, Java, and more.