4.0 Apply and Explain GOF Patterns - Satyum97/Course-Management-System GitHub Wiki

1) Sequence diagram for UC1. Sign up for the system. Here, there are three actors Admin/Student/Instructor that have the rights to do so.

GOF Patterns Used:

1. Builder Pattern: Here the model creates complex objects using simple objects passed by the controller.
2. Singleton Pattern: Only a single instance of the database manager is generated and shared all over the system.
3. Template Pattern: Here while creating an object the controller refers to the skeleton of the object that is in model.
4. Mediator Pattern: Controller acts as a mediator between database manager and the GUI.

2) Sequence Diagram for UC2. Login to the system. Here, there are three actors Admin/Student/Instructor that has the rights to do so.

GOF Patterns Used:

1. Builder Pattern: Here the model creates complex objects using simple objects passed by the controller.
2. Singleton Pattern: Only a single instance of the database manager is generated and shared all over the system.
3. Template Pattern: Here while creating an object the controller refers to the skeleton of the object that is in model.
4. Mediator Pattern: Controller acts as a mediator between database manager and the GUI.
5. Null pattern: If no user is found, the system returns a null user and the system shows to sign\up to the user.

3) Sequence diagram for UC3. Students search for courses. Here, there is only one actor Student that has the rights to do so.

GOF Patterns Used:

1. Builder Pattern: Here the model creates complex objects using simple objects passed by the controller.
2. Singleton Pattern: Only a single instance of the database manager is generated and shared all over the system.
3. Template Pattern: Here while creating an object the controller refers to the skeleton of the object that is in model.
4. Mediator Pattern: Controller acts as a mediator between database manager and the GUI.
5. Null pattern: If no courses are found, the system returns an empty list and then the system asks user to search with new criteria

4) Sequence diagram for UC4. Admin add/edits/deletes course info. Here, there is only one actor Admin that has the rights to do so.

GOF Patterns Used:

1. Builder Pattern: Here the model creates complex objects using simple objects passed by the controller.
2. Singleton Pattern: Only a single instance of the database manager is generated and shared all over the system.
3. Template Pattern: Here while creating an object the controller refers to the skeleton of the object that is in model.
4. Mediator Pattern: Controller acts as a mediator between database manager and the GUI.