====== Centralized Request Logic ======

Often in a web application, logic is duplicated among several types of requests.  Three patterns are used to consolidate this logic into a central location:

  * [[Front Controller]]
  * [[Intercepting Filter]]
  * [[Page Controller]] with common ancestor class

All three patterns interoperate well.

A [[Front Controller]] and [[Page Controller]] base classes are fairly interchangable and mostly used for implementing application specific logic.  Intercepting filters are used more for de-coupled request processing logic.

The type of logic that benefits from centralization include:

  * Logging and Auditing
  * Debugging
  * Security / Authorization
  * [[php:HTTP Header Manipulation]]
  * Response compression