A project of a new datatype called userexp, it stores the user exp and level. The method fromString is used by another extensions to increase or decrease the user exp and level.

Experience is stored in an array and there's a global exp:
 
 Just use fromString("exp|contentobject_id")
 
 Exp is the total exp, contentobject_id is the id of the object that is used like a category of the exp.
 
 There's a sample usage in the view userexp/test