1 On To Object Design Chapter 14 Applying UML and Patterns -Craig Larman

2 Connection between SSDs, System Operations and Layers In a well-designed layered architecture that supports high cohesion and a separation of concerns, the UI layer objects will then forward the request from the UI layer onto the domain layer for handling.

How design objects? Code : Design while coding Draw, then code : UML on a whiteboard, then switch to code Only draw: tools generate everything from diagrams. 3

WSEP 06 Designing Objects Static and dynamic modeling. Two kinds of object models: Static models : Class diagrams / Package diagram / Deployment diagram Helps design definition of packages, class name, attributtes and method signature Dynamic models : Interaction Diagrams/ (Sequence / comunication). State machine diagrams/activity diagram Illustrate how objects collaborate via messages and methdos. They help design the logic and method bodies

5 Agile modeling practice  Create Models in parallel! ( interaction diagram and class diagram)  Modeling with others

6 UML INTERACTION DIAGRAMS Chapter 15 Applying UML and Patterns -Craig Larman

Sequence Diagrams 7 A First Look at interaction Diagrams Illustrate how objects interacts with each other. Emphasizes time ordering of messages. Can model simple sequential flow, branching, iteration (loop), …etc Sequence / communication

sequence diagram Each new object is added to the right Method of Object A Class A has an attribute of type B to be able to call doTwo and doThree. Methods of Object B

Code public class A { private B myB= new B(); Public void doOne() { myB.doTwo(); myB.doThree(); } Class A has an attribute of type B. Class A has a method named doOne Class B has methods named doTwo and doThree

Communication diagram

Interaction Diagram notation

Common UML Interraction diagram notation lifeline

Basic Sequence diagram n o tation

How to illustrate a return result ? Is equivalent to

Messages sent to itself

Creation of Instances Dashed line Sale class will invoke the new operator and call the constructor.

Object destruction

Conditional message : OPT frame is placed around one or more messages. opt : Optional fragment that execute if guard [color=red] is true

Conditional message : UML1.x notation

which notation do you prefer?

Loops (iteration over a collection)

Code page

Loops (iteration over a collection)

Which notation do you prefer

Nesting of frames 25

How relate Interaction diagram? 26

Invoke static (class)methods 27

Polymorphism in interaction diagrams? 28

UP artifacts influencing OO design

Questions? 30

aMember: BookBorrower theLibraryMember: LibraryMember theCopy: CopytheBook: Book borrow (theCopy) 1: okToBorrow 2: borrow 2.1:borrowed Can you guess the scenario from this interaction diagram ?

Collaboration diagram: Library System