Chain of Responsibility

Intent, Motivation, Applicability, Structure, Participants, Collaborations, Consequences, Implementation, Sample Code, Known Uses, Related Patterns

Participants

• Handler (HelpHandler)

• defines an interface for handling requests.
• (optional) implements the successor link.
• ConcreteHandler (PrintButton, PrintDialog)

• handles requests it is responsible for.
• can access its successor.
• if the ConcreteHandler can handle the request, it does so; otherwise it forwards the request to its successor.
• Client

• initiates the request to a ConcreteHandler object on the chain.

Participants of Abstract Factory, Adapter, Bridge, Builder, Chain of Responsibility, Command, Composite, Decorator, Facade, Factory Method, Flyweight, Interpreter, Iterator, Mediator, Memento, Observer, Prototype, Proxy, Singleton, State, Strategy, Template Method, Visitor