Sub-Phase Low Level Design (cont)

More UML – Class Diagram Method Syntax [visibility] name [(parameter-list)] [: return-type] [visibility] [(parameter-list)] + means public name of parameter + type - means private void is default # means protected NOTE: the square brackets indicate that their contents are optional, the square brackets should not be included on your class diagram Janice Regan, 2008

More UML – Class Diagram Attribute Syntax [visibility] name [multiplicity] [: type] [= initial-value] [{property-string}] [visibility] [{property-string}] + means public changeable - default - means private frozen - constant # means protected NOTE: the square brackets indicate that their contents are optional, the square brackets should not be included on your class diagram Janice Regan, 2008

Updating classes Should use all parts of the syntax provided on the previous two slides in your class diagram. The exception is when one of the fields is not appropriate to the attribute or method being described E.g. No parameters given indicates there are none We have discovered attributes and methods for each class now we need to fill in the information to give a full description in our class diagram Need data types Need to determine visibility of methods (should have parameter lists already) Janice Regan, 2008

Patron and Resource class attributes +Name:String +Address:String +Phone # :String +Patron ID: integer +List of borrowed resources[0..24]:Long[ ] . . . +get ExpiryDate( ) : Date +getName( ) : String +checkIn(call# : integer) Janice Regan, 2008

Validation & Verification: Class Design All requirements developed during analysis must be addressed during design All design documents and diagrams must cross reference fcn requirements from the requirements specification Verification: Design diagrams created by diff. software developers To ensure all pieces fit together: Informal walk-through Run through each scenario, following diagrams Ensure that messages use method signature correctly Janice Regan, 2008

Summary of Low Level Design Refine scenarios from refined use cases created during Requirement Analysis and refined during High Level Design Refine class diagrams by adding attribute details from class diagrams created for each use case in Requirement Analysis, and refined scenarios produced in the above step For each refined scenario, develop interaction diagrams: collaboration or sequence diagrams Further refine class diagrams by adding methods these methods are implied from the inter-object communication conveyed in the scenarios' interaction diagrams Define algorithm for each method Janice Regan, 2008