Common closure principle
The Common closure principle is concerned with program maintainability. It states:
- The classes in a package should be closed together against the same kind of changes. A change that affects a package affects all the classes in that package. ifacethoughts.net
<Big>"</Big>More important than reusability is maintainability<Big>"</Big>,
<Big>"</Big>The CCP is an attempt to gather together in one place all the classes that are likely to change for the same reasons<Big>"</Big> This is closely related to the Open closed principle. Robert Cecil Martin 1996b
Although most design principles advocate loose-coupling between classes, sometimes it is unavoidable. This may be because of a consequence of the design, or a deliberate action such as performance tuning. In these cases, these classes should be packaged together, so a change only affects the classes in that package. This makes updating the system easier, as only the new package needs to be distributed. The Law of Demeter is a useful way to find out which classes know other's structure, and thus should probably be in the same package.
