layout, title, folder, permalink, pumlid, categories, tags
| layout | title | folder | permalink | pumlid | categories | tags | |||
|---|---|---|---|---|---|---|---|---|---|
| pattern | Bridge | bridge | /patterns/bridge/ | BSR14SCm20J0Lf82BFxf1akCJ4R26ZZYzkE7zxLljJgoIVfu7S2A3v7pLRhYo3r3l9u6CPHwJjAH5uETllpZhKbejsqn86v1a-CExQwj2mdgqv8-oyev_W00 | Structural |
|
Also known as
Handle/Body
Intent
Decouple an abstraction from its implementation so that the two can vary independently.
Applicability
Use the Bridge pattern when
- you want to avoid a permanent binding between an abstraction and its implementation. This might be the case, for example, when the implementation must be selected or switched at run-time.
- both the abstractions and their implementations should be extensible by subclassing. In this case, the Bridge pattern lets you combine the different abstractions and implementations and extend them independently
- changes in the implementation of an abstraction should have no impact on clients; that is, their code should not have to be recompiled.
- you have a proliferation of classes. Such a class hierarchy indicates the need for splitting an object into two parts. Rumbaugh uses the term "nested generalizations" to refer to such class hierarchies
- you want to share an implementation among multiple objects (perhaps using reference counting), and this fact should be hidden from the client. A simple example is Coplien's String class, in which multiple objects can share the same string representation.