21 CHAIN OF RESPONSIBILITY
This pattern was previously described in GoF95.
The Chain of Responsibility pattern (CoR) recommends a low degree of coupling between an object that sends out a request and the set of potential request handler objects.
When there is more than one object that can handle or fulfill a client request, the CoR pattern recommends giving each of these objects a chance to process the request in some sequential order. Applying the CoR pattern in such a case, each of these potential handler objects can be arranged in the form of a chain, with each object having a pointer to the next object in the chain. The first object in the chain receives the request and decides either to handle the request or to pass it on ...