Chain of Responsibility

Avoid coupling the sender of a request to its receiver by giving more than one object a chance to handle the request. Chain the receiving objects and pass the request along the chain until an object handles it.

Applicability

• More than one object may handle the reqest, and the handler isn't known.
• Need to avoid specifying the reciever of a request explictly.
• Need to specify the set of handlers dynamically.

Consequences

• Reduces coupling
• Added flexibility in assigning responsibilities to objects
• Receipt isn't guaranteed