Metamodel classes

Overview

The classes of the metamodel (as well as basic classes and work products) are the only classes available from J. Their definition can be extended by adding J methods or class attributes, but not by adding new instance attributes. New classes cannot be created.

Access to a model's information is deduced from the graphical representation of the metamodel.

Note: The work product class ("MpGenProduct") is an exception.

Accessing attributes

An object's attributes are accessed through the "." notation, by simply using their name:

Class c = ...;

String n;

n = c.Name;

or in the context of a Class:

String n;

n = Name; // equivalent to : n = this.Name

Accessing associations

Access to associations is achieved by concatenating the role name with the association destination class name or one of its derived classes.

Figure 2. Extract of the metamodel used

Class c= ...

Feature[] theFeature;

Attribute[] theAttributes;

// Access to the class c features :

// role == Part , destination class == Feature

theFeatures = c.PartFeature;

// Access to the class c attributes

// (the attributes are features)

// role == Part, destination class == Attribute

theAttributes = c.PartAttribute;

The type of object obtained also depends on the association's maximum multiplicity:

· If it is equal to 1, a simple object, which may be empty, is returned.

· If it is greater than 1, an object set, which may be empty, is returned.