Question

In Dr. Exman's case study applying Linear Software Models to a canonical system, i.e, the Observer design pattern, he obtained a subject module consisting of three functionals and three structors. In particular, what do you think is the "Subject resource" structor that provides the "Maintain global-state" functional? Research on the Observer design pattern and explain your thoughts on this. If you believe this is correct, does the "Subject resource" structor correspond to a class in the design solution? How does it support the "Maintain global-state" functional? If you think this is incorrect, and this structor is not really needed in the design solution, the modularity matrix won't be a square matrix. Where could it be wrong?

Answer 1

The "Subject resource" structor is essential in the Observer design pattern as it corresponds to the class that maintains the state and notifies observers of changes.

Step-by-step explanation:

The student's question revolves around Dr. Exman's case study on applying Linear Software Models to a canonical system, specifically to the Observer design pattern. In this context, a "Subject resource" structor is mentioned, which purportedly provides the "Maintain global-state" functional.

In the Observer pattern, the subject resource is crucial as it maintains the state of the object and notifies the observers when the state changes. Yes, this structor does indeed correspond to a class in the design solution and is typically the class that holds the state of interest.

The subject resource supports the "Maintain global-state" functional by being the source of truth for the data that observers are interested in, and upon any change in state, it is responsible for notifying all the subscribed observers so they can update their own state accordingly.

If, theoretically, one were to argue that the "Subject resource" structor is not required, the modularity matrix indeed would not be square, which could indicate a flaw in the model's structure or an oversight in accounting for all necessary components.

However, in practice, this structor is fundamental to the functionality of the Observer pattern because it underpins the central mechanism of state maintenance and communication between different parts of the system.

It ensures the 'Maintain global-state' functionality by being the centralized source of the data state, thus justifying its presence in the modularity matrix.