UML Extensibility Mechanisms (1/3)
Stereotype:
- each model element can be further classified by means of a stereotype
- «...» near the name of the element
- used instead of an extension of the metaclass hierarchy
Tagged Value:
- arbitrary information can be attached to a model element
- is not interpreted by UML
- there exist pre-defined ones, e.g., persistence={transitory,persistent}
- there may be user-defined ones, e.g., author={...}
Constraint:
- can be defined in an arbitrary language, e.g., OCL (Object Constraint Language)
- Example for a predefined one: generalization may be overlapping or disjoint