Chain of Responsibility Pattern

• Rules of thumb

    Chain of Responsibility, Command, Mediator, and Observer, address how you can decouple senders and receivers, but with different trade-offs. Chain of Responsibility passes a sender request along a chain of potential receivers.
    Chain of Responsibility can use Command to represent requests as objects.
    Chain of Responsibility is often applied in conjunction with Composite. There, a component’s parent can act as its successor
http://sourcemaking.com/design_patterns/chain_of_responsibility

• Chain-of-responsibility pattern

the chain-of-responsibility pattern is a design pattern consisting of a source of command objects and a series of processing objects. Each processing object contains logic that defines the types of command objects that it can handle; the rest are passed to the next processing object in the chain. A mechanism also exists for adding new processing objects to the end of this chain.
http://en.wikipedia.org/wiki/Chain-of-responsibility_pattern