Includes are php files containing common logic that you include in your actions.
Includes are stored in the app/includes and/or
app/libraries directories.
To include a file from one of these directories use the
Atomik::needed() method. It takes as first
argument the path to the filename you wish to include relative to the
previous directories and without the extension.
Example 8.1. Using includes
Let's say we've created the file app/includes/common.php
Atomik::needed('common');
You can use sub directories. To include a file stored at
app/includes/libs/db.php:
Atomik::needed('libs/db');