johnnystefan/pattern-bridge

Skill: Implement Bridge Pattern

Purpose

Splits a large class or a set of closely related classes into two separate hierarchies—abstraction and implementation—which can be developed independently.

Procedural Instructions

1. Identify Orthogonal Dimensions: Find independent dimensions in your classes (e.g., Abstraction vs. Platform).
2. Define Implementation Interface: Create a common interface for all concrete implementations.
3. Define Abstraction: Create a base class that maintains a reference to the implementation interface and delegates work to it.
4. Refine Abstractions: Create subclasses for specific logic variations.

TypeScript Example

// Implementation Interface
interface Device {
  isEnabled(): boolean;
  enable(): void;
  disable(): void;
}

// Concrete Implementation
class TV implements Device {
  private on = false;
  isEnabled() {
    return this.on;
  }
  enable() {
    this.on = true;
  }
  disable() {
    this.on = false;
  }
}

// Abstraction
class RemoteControl {
  constructor(protected device: Device) {}
  togglePower() {
    this.device.isEnabled() ? this.device.disable() : this.device.enable();
  }
}

// Refined Abstraction
class AdvancedRemote extends RemoteControl {
  mute() {
    console.log('Device muted');
  }
}

Payoff

• Platform Independence: You can create apps that work across different platforms.
• Scalability: Avoids an exponential explosion of subclasses.