In XDE, all parameters, attributes, and association ends have a TypeExpression field, which is an arbitrary string used to hold the type of the element. For parameters and attributes, this string is displayed on diagrams. In the Rational® modeling products, parameters and properties (which are the UML 2.0 equivalent of both attributes and association ends) have a Type field. This field is not a string, it is a reference to a type element within a model. This difference between an arbitrary string and an element reference causes problems when you import models that make extensive use of the TypeExpression field in XDE.
Finding the correct element for the Type reference is a four-step process during the import process if the XDE element is a parameter or an attribute:
In XDE, the TypeExpression field of an association end is completely independent from the target element of the association corresponding to that association end. In the Rational modeling products, the Type field of a property element that is also an association end must refer to the element that is the target of the association. It is not possible to set the Type field to point somewhere else without also redirecting the association itself. Therefore, it is not possible to use the information in the TypeExpression field of the XDE model to set the Type field in the imported model. Instead, a stereotype property is used to preserve the XDE TypeExpression string during import, though not in a way that is easily visible.
If the TypeExpression field for an association end is not empty, then the stereotype «XDE TypeExpression» is applied to the corresponding property element in the Rational modeling product, and the stereotype property TypeExpression is set to the value of the XDE TypeExpression field. This stereotype property is only visible on the Advanced page of the Properties window for the property model element.