OOD - Principles Design Class Diagrams Chapter 10 pp ; ;

Where are we? 2 Design Chapters Ch 7Designing User & System Interfaces Ch 10OO Design – Principles Ch 11OO Design – Use Case Realizations Ch 12Databases, Controls & Security

OOD: Object-Oriented Design  From "Domain Classes" to "Programming Classes"  Specify objects to carry out each use case 3

From Requirements (Analysis) to Design… 4 Ch10 Ch11

Defining a Single Design Class 5

Domain Class vs. Design Class 6

Design Class: Things to Know  Elaborate attributes  Define Method types  Write Method Signatures  Identify Instance-Level and Class-Level Attributes & Methods 7

Elaborating Attributes visibility attributeName: dataType {property}  Visibility Public or Private  Data type Numbers: integer, double Text: string True/False: boolean Dates: dateTime  Property key 8

Method Types  3 Method types Constructor methods Accessor methods − Get − Set Processing methods 9 9:05 & 10:1 0

Method Signatures visibility methodName(parameterList) : returnType  Visibility Public or Private  Method name Verb phrase  Parameter List Inputs  Return Type Output Typical data type: integer, string, etc Object (e.g. Student) Collection of objects: StudentArray 10

Instance-Level vs. Class-Level Attributes & Methods Instance-Level − Pertains to an individual object/instance − Attribute  name − Method  getName(), calcGPA() Class-Level − Does not pertain to an individual object/instance − Attribute  tuitionPerHour − Method  findAboveHours() 11 -tuitionPerHour: integer

Exercise  Design a Design Class for: Vehicle Attributes − Primary Key − Instance attribute − Class Attribute Method − Constructor method − Instance Method Accessor methods (2) Processing method − Class Method & 1010

A Design Class (coded in VB) 13

14 Design Class Diagram Overridden Method How many attributes are there in a MailOrder object?

Designing a Domain Class Diagram 15

Review – let’s understand this Use Case before continuing  Use Case Description “Process New Order” 16

Review – let’s understand this model before continuing  Domain Class Diagram 17

Steps: Initial Design Class Diagram 1. Select a Use Case: “Process New Order” 2. Add Domain Classes See pre-conditions & post-conditions for ideas 3. Elaborate Attributes: visibility, data types 18

Steps: Initial Design Class Diagram 4. Add a "Controller" class − Switchboard between the View & Domain Layer; a collection point for incoming messages. Include one per use case. 19

Steps: Initial Design Class Diagram 5. Add Navigation Visibility (def) the ability of one object to interact with another 20 1 to Many Association 1  * Mandatory Associations Indep  Dependent Needs info Sender  Receiver Rules

Steps: Initial Design Class Diagram 6. Add Methods (we will see this in Ch 11 via Sequence Diagrams) That is, Behavior! 21