Chapter 10 PowerDesigner Public Metamodel

Classes

Classes are used to represent metadata in the following way:

• Abstract classes are used to share attributes and behaviors. They are not visible in the PowerDesigner interface. Instantiable classes inherit from abstract classes via generalization links. For example, NamedObject is an abstract class, it stores standard attributes like name, code, comment, annotation, and description inherited by most PowerDesigner design objects
• Instantiable/Concrete classes correspond to objects displayed in the interface, they have their own attributes like type or persistence, and they inherit attributes and behaviors from abstract classes through generalization links

The PowerDesigner metamodel highlights the inheritance links among metadata.

Class attributes

Attributes are class properties that can be derived or not. Classes linked to other classes with generalization links usually contain derived attributes that are calculated from the attributes or collections of the parent class. Non-derived attributes are proper attributes of the class. These attributes are stored in the model and saved in the model file.

Neither derived attributes, nor attributes migrated from navigable associations, are stored in the model file.

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