Thesis full text (PDF) - Politecnico di Milano

These patterns do not have side effects on the knowledge base. Whenever it is necessary, we
exploit the UML utility class Complex Query to transfer values from one component to another.
The role of this class is to orchestrate the invocation of the methods in the pattern. Its
configuration determines the methods invocation order (possibly including looping and
conditional execution), thus eliminating the burden of controlling the flow of components
execution.
3.3.1.1 Class and its classification pattern
This pattern checks the existence of a class in the knowledge base and deducts the hierarchy of
generalizing classes. It encompasses two exploration components (figure 3.25): (i) the Class
Component configured with a ClassOfName selection condition to retrieve the class
corresponding to the input, and (ii) the Classes Hierarchy Component configured with a
ClassOfSubClass condition to deduct the hierarchy above the previous class. The input received
by the user invoking the execute method is transferred to the Class Component; the deducted
class becomes the input for the Class Hierarchy Component, while both the class and the
retrieved hierarchy are returned to the user. The pattern is defined as the one extracting the
specializing class hierarchy for a given input.
This pattern may be used whenever the user needs to analyze a specific class and its generalized
classes.
Figure 3.25: Class and its classification
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