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Generalization

ElementClasses can define a superclass. Instances of one of these ElementClasses can then also be used as an instance of the SuperClass.

This feature is designed to support polymorphism in the models.

  • References can target an abstract ElementClass. Subclasses can then provide a variety of implementations for the superclass.

  • Expanders can also target the superclass to expand artifacts that are common for the subclasses.

  • The ElementClass will inherit all Attributes and References of its superclass.

  • The superclass itself needs to be abstract. Abstract ElementClassed cannot be instantiated. Instead, they can only be represented by subclasses.

  • Optionally, the superclass can be sealed. In this case, it cannot be extended by ElementClasses from other ontologies. This means all subclasses are known and can be enumerated.

<elementClass name="EnumType">
  <group name="root" ontology="enumTypeElements"/>
  <role name="element"/>
  <superClass name="ValueType" ontology="elements"/>
  <attributes>
    <attribute name="packageName">
      <isIdentifier>false</isIdentifier>
      <dataType name="PackageName" ontology="enumTypeElements"/>
    </attribute>
  </attributes>
</elementClass>
<elementClass name="ValueType">
  <isAbstract>true</isAbstract>
  <isSealed>false</isSealed>
  <group name="valueTypes" ontology="elements"/>
  <role name="data"/>
  <attributes>
    <attribute name="name">
      <isIdentifier>true</isIdentifier>
      <dataType name="Name" ontology="elements"/>
    </attribute>
    <attribute name="description">
      <isIdentifier>false</isIdentifier>
      <dataType name="Description" ontology="elements"/>
    </attribute>
  </attributes>
</elementClass>