Optional framework files

These optional files are used (included) by the framework, if they exist. If not, nothing happens (no errors). So, you can use them only if you need them.

init.php
This file is included by the framework only the first time that the application is openned (at the beginning of the session).It may be used to initialize anything.
global.php
This file is included every time, if it exists. It may contain functions, constants and variables that are used throughout the whole application.
before_page.php
This file is included before each page is parsed.
after_page.php
This file is included after each page is constructed.