is my approach to using DB_DataObject sensible?

Hello, I'm using DB_DataObject for the first time. After playing around with it a bit, and given the following: * I don't want to edit the auto-generated classes * I want to define behaviors for my database objects * I want to override the fetch() method, as suggested in the

     documentation, to add properties that are not stored in the
     underlying tables

I've decided to extend the auto-generated classes and use the new classes in my application. As a concrete example, here's the User class for my Web app: <?php require_once('DB/DataObject.php'); /*

    * Load the base class (DataObject_User).  There's no way to do this

without

    * instantiating, but we discard the resulting object because we're

extending

    * the class.
    */

DB_DataObject::Factory('User'); class MyAppUser extends DataObject_User {

           var $role;

           // override fetch() to add 'role' to the object:

           function fetch() {

                   if ($result = parent::fetch()) {

                           $this->role = $this->getLink('role_id');
                   }

                   return $result;
           }

} ?> 'Role_id' is the foreign key of a UserRole table. I'd like to get feedback on whether this is a sensible approach. In particular: am I correct in saying that DB_DataObject::Factory() is the only way to load the class? I can't extend the class until it's loaded. It seems a bit inelegant, but I've not seen any other way to do this. Comments welcome. Thanks, Roger Rohrbach