1. Composite Pattern
Oct 7, 2003
A composite is a group of objects in which some objects contain others; one object may represent groups, and another may represent an individual item, a leaf.

2. Composite Pattern
Generic UML class diagram *
Client
Component
Operation()
Leaf
Composite
Operation()
Operation()
Other()

3. Composite Pattern
Consider a UML class diagram for machines. Machines may be complex and contain other machines. * * 1
PlantFloor
MachComponent
getMachineCount() 1
Machine
MachComposite
components: List
getMachineCount()
getMachineCount()

4. Composite Pattern
An object diagram illustrating the machine on floor 5 of the plant
floor5 :Plantfloor
M1: MachComposite
L1: Machine
L2: Machine
M9: MachComposite
L7: Machine
L4: Machine

5. Exercise
Apply composite to a model for companies. Each company may comprise other companies. Some companies are simple and do not have any structure. Note the general structure for a company is hierarchical – a tree structure.
Illustrate the model as a class diagram.
Make up two companies; one that is simple and the other a complex tree structure. Illustrate with an object diagram.

6. Illustrate the model as a class diagram.
Exercise
See handout from “Software Pioneers”
Apply composite to a model for testing programs. Each program is tested by running a number of test cases. A test suite is a collection of test cases. A test suite can be used to test a program.
Suppose test suites can be combined to form larger test suites; that is, a test suite may be composed of individual test cases and of other test suites. In general then, a suite of tests for a program looks like a tree structure.
Illustrate the model as a class diagram.
Suppose you have a program X that has five test cases. Three of these are organized into TestCase1; two are organized into TestCase2. Illustrate the object diagram.