Design Patterns Implementation
Table of Contents
Overview
Apply proven design patterns to create maintainable, extensible, and testable code architectures.
When to Use
- Solving common architectural problems
- Making code more maintainable and testable
- Implementing extensible plugin systems
- Decoupling components
- Following SOLID principles
- Code reviews identifying architectural issues
Quick Start
Minimal working example:
class DatabaseConnection {
private static instance: DatabaseConnection;
private connection: any;
private constructor() {
this.connection = this.createConnection();
}
public static getInstance(): DatabaseConnection {
if (!DatabaseConnection.instance) {
DatabaseConnection.instance = new DatabaseConnection();
}
return DatabaseConnection.instance;
}
private createConnection() {
return {
/* connection logic */
};
}
}
// Usage
const db1 = DatabaseConnection.getInstance();
const db2 = DatabaseConnection.getInstance();
// ... (see reference guides for full implementation)Reference Guides
Detailed implementations in the references/ directory:
| Guide | Contents |
|---|---|
| Singleton Pattern | Singleton Pattern |
| Factory Pattern | Factory Pattern |
| Observer Pattern | Observer Pattern |
| Strategy Pattern | Strategy Pattern |
| Decorator Pattern | Decorator Pattern |
| Repository Pattern | Repository Pattern |
| Dependency Injection | Dependency Injection |
Best Practices
✅ DO
- Choose patterns that solve actual problems
- Keep patterns simple and understandable
- Document why patterns were chosen
- Consider testability
- Follow SOLID principles
- Use dependency injection
- Prefer composition over inheritance
❌ DON'T
- Apply patterns without understanding them
- Over-engineer simple solutions
- Force patterns where they don't fit
- Create unnecessary abstraction layers
- Ignore team familiarity with patterns