Contents
How are extension classes referenced in a model?
Any number of extension classes can augment a given artifact in a particular model. Extension classes are never referenced directly by the programmer, only by the runtime system. Any class that inherits from an augmented class also inherits the effective class.
What kind of model is the extended entity relationship?
The Extended Entity Relationship Model. The Extended Entity-Relationship (EER) model is a conceptual (or semantic) data model, capable of describing the data requirements for a new information system in a direct and easy to understand graphical notation.
Where is the public instance method in X + +?
The public instance method ( ExtensionMethod) is defined in the extension class. Therefore, it’s available just as if it were defined in MyClass in the context of the model where the extension class is defined. The following example shows how to call the method in the model.
Is there an extension model for X + + code?
This article describes how X++ code can be extended, so that you can add methods and state to artifacts that are defined in other models without recompiling those models. A similar code extension mechanism already exists for X++ and is modeled after the corresponding feature in C#.
Why is the extension class marked as final?
The class augments the artifact that is specified in the parameter of the ExtensionOf attribute, as shown in the following example. Because the classes are instantiated by the runtime system, it’s not meaningful to derive from the extension class. Therefore, the extension class must be marked as final.
How does C + + support the concept of extending classes?
It acts as the foundation for the concept of extending classes (or derived classes). C++ supports this concept. Inheritance is the ability to inherit properties from one class (base class) to another class (derived class). C++ allows the user to construct new classes from the existing classes.