Fundamentals of Object-Oriented Design in UML

Meilir Page-Jones is President and Senior Consulting Methodologist at Wayland Systems, and has extensive experience in training, consulting, and hands-on system development. He created several of Wayland's courses on object-oriented software engineering and project management, including The Synthesis Method for Object-Oriented Systems Development and Analysis and Design for Client/Server Systems Development. Formerly the head of the Structured Design Department at Yourdon Inc., Meilir wrote the best-selling Practical Guide to Structured Systems Design and Practical Project Management. He has also written numerous articles for the Journal of Object-Oriented Programming, Object Magazine, Software Development Magazine, and Computerworld, and has spoken at many conferences, including OOPSLA, Software Development, and Object Expo. 020169946XAB04062001

I. INTRODUCTION.

1. What does it mean to be object oriented, anyway?


Encapsulation.



Information / implementation hiding.



State retention.



Object identity.



Messages.



Message structure.



Message arguments.



The roles of objects in messages.



Types of messages.



Classes.



Inheritance.



Polymorphism.



Genericity.

2. Object orientation--who ordered that?


Where did object orientation come from?



Larry Constantine.



O.J. Dahl and K. Nygaard.



Alan Kay, Adele Goldberg and others.



Edsger Dijkstra.



Barbara Liskov.



David Parnas.



Jean Ichbiah and others.



Bjarne Stroustrup.



Bertrand Meyer.



0 Grady Booch, Ivar Jacobson and Jim Rumbaugh.



Object orientation in a social context.



The history of the mainstream.



To the barricades: the object-oriented revolutionaries.



Forward to the past: the object-oriented reactionaries.



Enter the evolutionists (stage middle).



Object orientation as an engineering discipline.



What's object orientation good for?



Analyzing users' requirements.



Designing software.



Constructing software.



Maintaining software.



Using software.



Managing software projects.

II. UML NOTATION.

3. The basic notation for classes, attributes and operations.


The class symbol.



Notation for attributes.



Notation for operations.



Overloaded operations.



Public, protected and private features.



Class attributes and operations.



Abstract classes and features.



The utility.



Parameterized classes.

4. Class diagrams.


The generalization construct.



Single inheritance.



Multiple inheritance.



Subclass partitioning.



Partitioning discriminators.



The association construct.



The basic UML notation for associations.



Associations depicted as classes.



Higher-order associations.



Navigability of associations.



"Whole / part" associations.



Composition.



Aggregation.

5. Object-interaction diagrams.


The collaboration diagram.



Depicting a message.



Polymorphism in the collaboration diagram.



Iterated messages.



Use of self in messages.



The sequence diagram.



Asynchronous messages and concurrent execution.



Depicting an asynchronous message.



The callback mechanism.



Asynchronous messages with priority.



Depicting a broadcast (non-targeted) message.

6. State diagrams.


Basic state diagrams.



Nested states.



Concurrent states and synchronization.



Transient states from message-result arguments.



Continuously variable attributes.

7. Additional design diagrams.


Depicting system architecture.



Packages.



Deployment diagrams for hardware components.



Deployment diagrams for software components.



Depicting the human interface.



The window-layout diagram.



The window-navigation diagram.



A brief digression: what's object-oriented about a GUI?

III. FUNDAMENTAL DESIGN PRINCIPLES.

8. Encapsulation and connascence.


Encapsulation structure.



Levels of encapsulation.



Design criteria governing interacting levels of encapsulation.



Connascence.



Varieties of connascence.



Contranascence.



Connascence and encapsulation boundaries.



Connascence and maintainability.



Connascence abuses in object-oriented systems.

9. Domains, encumbrance and cohesion.


Domains of object classes.



The foundation domain.



The architectural domain.



The business domain.



The application domain.



The source of classes in each domain.



Encumbrance.



Definition of encumbrance.



The use of encumbrance.



The Law of Demeter.



Class cohesion: a class and its features.



Mixed-instance cohesion.



Mixed-domain cohesion.



Mixed-role cohesion.

10. State space and behavior.


State-space and behavior of a class.



The state-space of a subclass.



The behavior of a subclass.



The class invariant as a restriction on a state-space.



Preconditions and postconditions.

11. Principles of robust class hierarchies.


The principle of type conformance.



Subclasses as subtypes.



Conformance: the principles of contravariance and covariance.



An example of contravariance and covariance.



A graphic illustration of contravariance and covariance.



A summary of the requirements for type conformance.



The principle of closed behavior.

12. The perils of inheritance and polymorphism.


Abuses of inheritance.



Mistaken aggregates.



Inverted hierarchy.



Confusing class and instance.



Misapplying is a.



The danger of polymorphism.



Polymorphism of operations.



Polymorphism of variables.



Polymorphism in messages.



Polymorphism and genericity.

13. Organizing features.


Mix-in classes.



A business example.



A graphics example.



Rings of operations.

14. Quality of a class interface.


State support in a class interface.



Behavior support in a class interface.



Operation cohesion in a class interface.

15. Development of an object-oriented component.
Appendices.
Appendix A Checklist for an object-oriented design walkthrough.
Appendix B The object-oriented design owner's manual.
Bibliography.
Glossary.
Index. 020169946XT04062001