This project contains examples of local handlers for Moodle 2.x events such as user_created, user_enrolled ...

Use it as a model to write your own event handlers.

USAGE :

Git clone this by going to local directory of your Moodle 2.x installation

cd /var/www/moodle/local 
git clone https://github.com/patrickpollet/moodle_local_insalyon.git insalyon

The name of the extraction directory in mandatory since Moodle will search a file lang/local_insalyon.php for localized strings

Go to Site Adminstration then Notifications. You should see that a local plugin named 'personnalisations...' needs to be updated. 
Press continue.

This has installed several local handlers for interesting Moodle events (see insalyon/db/events.php for a list). 

Most of these handlers do nothing, just logging that they were called  and with what parameters in a file named pp_debug_errors_log in your moodledata directory.
This should give you all needed informations about the parameter received from Moodle core. 

One one them DO the real thing :groups_group_created . Every time a group is created in a Moodle course, a grouping with the same name is automagically created.


Enjoy