CSC/ECE 517 Summer 2008/wiki3 6 esb
Protected Variation
Description of protected variation
Chapter 25 pp 427-433 -- Protected variation and Polymorphism Protected Variation and Polymorphism seem related. What is the difference between the two? Where would you apply one pattern over the other?
Polymorphism is a powerful technology that is very useful for handling Protected Variation. Protected Variation gives one reason "why" for a particular use of Polymorphism.
See next... . Chapter 25.4 pp 434 -- OCP An example of an .Key Open-Closed Principle is... X can be opened to Y and always Z. And it's only open to Y if it Y needs to access something and has permission to. While Z can always access it because it has permission to. That look right?
I'd express it like this: if X uses Y in some way or other you don't want changes to Y to effect X, but you also want to be able to change Y in ways that don't change X.
Introduction
Keep information out of the grasp of components that could damage integrity. Introduce reader to protected variation -Open/Closed Principle and Information Hiding
Why use Protected Variation?
General overview
- Example 1
- Example 2
How would you classify it
Coding Examples
Conclusion
See Also
External links
http://codecourse.sourceforge.net/materials/The-Importance-of-Being-Closed.pdf
http://www.rgoarchitects.com/Files/ooprimer.ppt#288,9,OCP Example