Dynamic attributing

$attribute = array( "LOM.LifeCycle.Publish.Date" => now() );
foreach( $learning_objects as $single_object )
        $single_object->set_attributes( $attribute );
$lesson->insert( $learning_objects );
...
$students_online = $lesson->get_visitors();
$attribute = array($lesson->get_id(), "was present");
foreach( $students_online as $single_student )
        $single_student->set_attributes( $attribute );