Command Pattern Implementor

Name: Command Pattern Implementor
Author: BookForge

Implement the Command pattern to encapsulate requests as objects, enabling parameterized operations, queuing, logging, and undo/redo. Use when you need to decouple UI elements from operations, implement multi-level undo with command history, support macro recording, queue or schedule requests, or log operations for crash recovery. Includes the complete undo/redo algorithm using a command history list with present-line pointer, MacroCommand for composite operations, and SimpleCommand template for eliminating subclasses.

Install

1. Add marketplace

› /plugin marketplace add bookforge-ai/bookforge-skills

2. Install plugin

› /plugin install design-patterns-gof@bookforge-skills

3. Use the skill

› /command-pattern-implementor

CC-BY-SA · Open sourceGitHub

Source Book

Design Patterns

Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides

Edit on GitHub

More from Design Patterns

Design Patterns

Abstract Factory Implementor

Implement the Abstract Factory pattern to create families of related objects without specifying their concrete classes. Use when a system must be independent of how its products are created, when it must work with multiple product families, when products are designed to be used together and you need to enforce that constraint, or when providing a class library revealing only interfaces. Covers factory-as-singleton, prototype-based factories, and extensible factory interfaces.

Design Patterns

Behavioral Pattern Selector

Choose the right behavioral design pattern from the 11 GoF behavioral patterns. Use when someone asks "how do I make this algorithm swappable?", "should I use Strategy or State?", "how do I decouple senders from receivers?", "what's the difference between Observer and Mediator?", "how do I add undo/redo?", "how do I traverse a collection without exposing its internals?", or "how do I add operations to classes I can't modify?" Also use when you see switch statements selecting between algorithms, tightly coupled event handlers, objects that change behavior based on state, or request-handling logic that should be distributed across a chain. Analyzes via two taxonomies — what aspect to encapsulate as an object (algorithm, state, protocol, traversal) and how to decouple senders from receivers (Command, Observer, Mediator, Chain of Responsibility) — with explicit trade-offs for each choice.

Design Patterns

Bridge Pattern Implementor

Implement the Bridge pattern to decouple an abstraction from its implementation so both can vary independently. Use when you want to avoid a permanent binding between abstraction and implementation, when both abstractions and implementations should be extensible by subclassing, when implementation changes should not require recompiling clients, or when you need to share an implementation among multiple objects. Includes the evaluate-extremes design process (union vs intersection of functionality) and Abstract Factory integration for runtime implementation selection.

Design Patterns

Composite Pattern Implementor

Implement the Composite pattern to compose objects into tree structures representing part-whole hierarchies, letting clients treat individual objects and compositions uniformly. Use when building file systems, UI component trees, organization charts, document structures, or any recursive containment hierarchy. Addresses 9 implementation concerns including the safety-vs-transparency trade-off for child management, parent references, component sharing, caching, and child ordering.