design-patterns-explained-with-food

Design Patterns Explained with Food 🥕

Introduction

The "Design Patterns Explained with Food" project is a creative approach to teaching the Gang of Four (GOF) design patterns. This project uses the concept of food to provide practical examples of design patterns, implemented in C#. The Gang of Four Design Patterns are essential elements of reusable object-oriented software, originating from the well-known book by Gamma, Helm, Johnson, and Vlissides.

Motivation

The typical teaching methods for these patterns often avoid incorporating external dependencies like databases, AMQP queues, email services, and HTTP APIs. While excluding these dependencies can simplify the core presentation of design patterns, it might not illustrate their use in realistic situations effectively. This project remedies that by incorporating mock versions of these dependencies into various business scenarios. Each example is crafted to balance simplicity and complexity, ensuring that the value of each pattern is clear without being overly simplistic.

Example Programs

Creational Patterns

1. Abstract Factory: An example using a Custom Meal Planner helps learners understand how to create families of diets with unique behaviors. It enables generating grocery lists and other data without needing concrete class specifications in client code.

2. Builder: Demonstrated through a Bakery Purchase Order System, this pattern separates the complex construction of purchase orders from their representation, allowing easy creation and management.

3. Factory Method: Illustrated by a Food Delivery Service, this pattern simplifies the process of introducing new delivery types without altering client code.

4. Prototype: A Dining Room Designer serves as a case study. This example allows the creation of deep copies of graphic objects like chairs and tables, facilitating easy manipulation without knowledge of internal states.

5. Singleton: Explained with an Ingredients Database Connection Pool, this pattern efficiently manages database connections, limiting the number of simultaneous connections.

Structural Patterns

1. Adapter: Using a Recipe Search tool, this pattern shows how to convert XML to JSON to fit a specific document store requirement by adapting interfaces seamlessly.

2. Bridge: In a Farmer's Market Simulator, this pattern demonstrates the separation of vendor types and payment processors, allowing independent enhancements.

3. Composite: With a Tea Cartonizer example, it treats whole cartons and individual teas uniformly, simplifying management and serving calculations.

4. Decorator: This pattern, exemplified by a Front-of-House Service, adds or modifies customer notification methods without complex subclassing.

5. Facade: Through a Grocery Store Report generator, it simplifies client interaction by masking complex underlying systems.

6. Flyweight: Illustrated in a Grocery Store City Planning Simulation, it conserves memory by sharing extrinsic data among similar objects in a simulation scenario.

7. Proxy: The Food Bank Donation Processor example, using this pattern, shows how to control access and usage logging while maintaining the same interface.

Behavioral Patterns

1. Chain of Responsibility: A Kombucha Order Processor demonstrates sequentially processing customer orders with dynamic changes based on conditions.

2. Command: Implemented in a Composter Sign-Up Form, this pattern encapsulates operational logic and data to facilitate complex onboarding processes.

3. Interpreter: Illustrated with a Chocolate Shop Barcode Reader, this pattern processes scanned data for efficient inventory management.

4. Iterator: Through a Best Restaurant Finder app, this pattern enables traversal through collections like restaurant rankings without exposing their complex structure.

5. Mediator: In a Food Truck Coordinator, it streamlines vehicle communication and operations across a city, handling complexity effectively.

6. Memento: Used in an e-commerce Doughnut Shop Cart, this pattern allows actions like undoing cart additions, enhancing user experience.

7. Observer: A Diet Plan Tracking App highlights using this pattern to efficiently broadcast profile updates to multiple services.

8. State: Demonstrated by a Cafe Rewards Program, it adapts the behavior of rewards based on the customer's loyalty tier.

9. Strategy: In a Restaurant Menu Changer, this pattern is employed to manage different processes for creating meal menus without code duplication.

10. Template Method: A Cookbook Printer uses this pattern to manage generic and customizable printing processes for recipes.

11. Visitor: Illustrated via Farmer's Market Research, it allows easy report generation by making data objects visitable without heavily modifying them.

Conclusion

The "Design Patterns Explained with Food" project creatively combines the world of food with the study of design patterns in software development. By providing relatable examples, it helps developers understand and apply these patterns using clear, practical scenarios.