Virtual and Real Classes
Virtual and Real Classes
The concept of virtual and real classes is a special feature of the Knowledge Provider
model layer. The concept applies to both the info object classes and the relationship classes. It supports the creation of a content model because by replicating a virtual class, more virtual classes or real classes can be defined as versions of the virtual class. When a virtual class is replicated, a duplicate of the entire class is made. Real classes inherit the instance attributes of the superior virtual IO class or relationship class. In contrast to copies, replicated real classes have a dynamic relationship to the superior virtual class. This means that changes made after replication to instance attributes of the virtual class are also made in the instance attributes of the real subordinate classes.All the other properties of the real classes are only copied from the virtual class and have no relationship to the superior virtual class.
No instance attributes can be added to or removed from real classes that were derived from virtual classes.
Inherited attributes are highlighted and cannot be changed; copied properties are displayed in the standard font.
You want to create various document templates for creating marketing pamphlets. To do this, create the virtual IO classes Fact Sheet and Sound in DMWB. Assign to both virtual IO classes the instance attributes Created by, Creation Date, Description, Last Changed by and Date of Change, as well as the standard properties. The real IO class inherits these instance attributes when you replicate the virtual info object classes. Standard properties and free properties are simply copied from the virtual IO class to the real IO class.