| layout | pattern | |||
|---|---|---|---|---|
| title | Decorator | |||
| folder | decorator | |||
| permalink | /patterns/decorator/ | |||
| categories | Structural | |||
| tags |
|
Wrapper
Attach additional responsibilities to an object dynamically. Decorators provide a flexible alternative to subclassing for extending functionality.
Use Decorator
- to add responsibilities to individual objects dynamically and transparently, that is, without affecting other objects
- for responsibilities that can be withdrawn
- when extension by subclassing is impractical. Sometimes a large number of independent extensions are possible and would produce an explosion of subclasses to support every combination. Or a class definition may be hidden or otherwise unavailable for subclassing