The Chain of Responsibility Pattern is a behavioral design pattern that allows a request to be passed along a chain of handlers. Each handler in the chain processes the request or passes it along to the next handler in the chain. This pattern decouples the sender and receiver of a request and allows for dynamic changes in the chain structure. 🔄
This pattern promotes flexibility by allowing multiple objects to handle requests without tightly coupling the sender and receiver. 🏗️
- Handler → Defines an interface for handling requests and linking to the next handler in the chain.
- Concrete Handlers → Handle specific types of requests and pass unhandled requests to the next handler in the chain.
- Client → Initiates the request and sends it through the chain of handlers.
✅ When you want to pass a request through a chain of objects, allowing each object to decide whether to process the request or pass it on.
✅ When you have a set of handlers that are independent and can process requests in a sequence.
✅ When you want to avoid tight coupling between request senders and receivers.
- Customer Support: Request goes through different support levels (e.g., Level 1 → Level 2 → Manager) until it is resolved 💬
- Logging Systems: Log messages are passed through different loggers (e.g., console, file, remote server) based on severity levels 📜
- UI Event Handling: Events are passed through a chain of event listeners before reaching the final target 🖱️
🔗 Example Code: See Implementation