copyright © hsiao-lan wei. 2003 all rights reserved design model interaction diagram

Copyright © Hsiao-Lan Wei. 2003 All Rights Reserved

Design Model

Interaction diagram

Copyright © Hsiao-Lan Wei. 2003 All Rights Reserved 2

Elaboration Iteration 1

On to Object Design

(OOD)


Analysis and Design

Analysis—“what”

investigation of the problem and requirements

Design—“how”

description of a software solution

Requirements

Use cases

Constraints

Vocabulary

Objects

Architecture

Deployment

UI


Object-oriented Analysis and Design

Object-oriented analysis

– What are the domain objects?

•Described in a domain object model

Object-oriented design

– Describing the software solution in terms of collaborating objects, with responsibilities.


Transition to Design During requirements and analysis work, we

– “Do the right thing”

– Understand the domain

– Clarify and record the constraints and requirements

– Essentially ignore thinking about the design, and focus on understanding the problem.

– . . .

During design, we– “Do the thing right”

– Create a software (and hardware) solution that meets the wishes of the stakeholders.


From Requirements to Design

A set of requirements-oriented artifacts (and thought) inspire design-oriented artifacts.

Domain Model Use Case ModelSupplementary Specs

(Req list andattributes,. . . )

Software ArchitectureDocument

Design Model Data Model

. . .

. . .


Changing Hats

Until this time, we have been wearing an “investigator” hat, essentially ignoring what the solution should be.

– “Do the right thing”

Now, we take off the investigator hat, and put on our “designer” hats.

– “Do the thing right”

Of course, in the context of iterative development, we do this repeatedly.


Objectives of Interaction Diagrams

Learn how to create interaction diagrams to model use-case behavior.

Understand the similarities and differences between sequence and collaboration diagrams.


So Where Are We?

Discovered boundary, control, and entity classes

Assigned responsibilities to each class

Determined how to use these classes to realize use-case scenarios


What are Interaction Diagrams?

An interaction diagram is a graphical representation of interactions between objects

– It models the dynamic aspects of a system.

There are two kinds of interaction diagrams Sequence diagrams

Collaboration diagrams

Each provides a different view of the same interaction Sequence diagrams are time ordered

Collaboration diagrams may include may data flow


What is a Sequence Diagram? A sequence diagram shows object

interactions arranged in time sequence

The diagram shows

The objects participating in the interaction

The sequence of messages exchanged

A sequence diagram contains:

Objects with their “lifelines”

Messages exchanged between objects in ordered sequence

Focus of control(optional)

Sequence Diagrams


Review: The Anatomy of Sequence Diagrams

1: PerformResponsibility

Client Object Supplier Object

Message

:Client :Supplier

Focus of Control

This is a sample script.

Reflexive MessageObject Lifeline

1.1: PerformAnotherResponsibility

Hierarchical MessageNumbering


A sequence Diagram

: Register : Sale

makePayment(cashTendered)


: Paymentcreate(cashTendered)

an activation box showingthe focus of control


What Is a Collaboration Diagram?

A collaboration diagram emphasizes the organization of the objects that participate in an interaction.

The collaboration diagram shows

– The objects participating in the interaction.

– Links between the objects.

– Messages passed between the objects.

Collaboration Diagrams


Sample Collaboration Diagram

1: makePayment(cashTendered)

1.1: create(cashTendered)

: Register :Sale

:Payment


creation indicated with a"create" message

direction of message

first message

instance

first internal message

link line

parameter


Creating Interaction Diagrams

Use cases are examined to determine the scenarios

Additional information may be needed to complete the scenario

Details of the system that have been omitted from the use case

Example : John enters the student ID number 369523449

Question : Where is the id number entered

Answer: Some sort of form is needed

• Registration form added


Sequence and Collaboration Diagram Similarities

Semantically equivalent

– Can convert one diagram to the other without losing any information

Model the dynamic aspects of a system Model a use-case scenario


Sequence and Collaboration Diagram Differences

Collaboration diagrams

– Show relationships in addition to interactions

– Better for visualizing patterns of collaboration

– Better for visualizing all of the effects on a given object

– Easier to use for brainstorming sessions

Sequence diagrams

– Show the explicit sequence of messages

– Better for visualizing overall flow

– Better for real-time specifications and for complex scenarios


Common interaction diagram notation

Classes and instances

Sale :Sale s1: Sale

class instance named instance


Basic Sequence Diagram Notation(1/5) Links

– Sequence diagrams do not show links Messages

– Message expression between objects is on an arrowed line.

Focus of control and activation boxes: Register : Sale

msg2()

msg3()

msg1()

msg4()

msg5()

: Register

msg1()

clear()


Basic Sequence Diagram Notation(2/5)

Creation of instances Object lifelines

: Register : Sale

makePayment(cashTendered) : Paymentcreate(cashTendered)

authorize()

note that newly createdobjects are placed at theircreation "height"

an object lifeline shows the extent ofthe life of the object in the diagram


Basic Sequence Diagram Notation(3/5) Conditional messages

Mutually exclusive conditional messages

: B: A

[ x < 10 ] calculate()message1()

: C

[ x > 15 ] calculate()

: Bar: Foo

[ color = red ] calculate()message1()


Basic Sequence Diagram Notation(4/5) Iteration for a single message

Iteration of a series of messages

: Simulator : Random

* [i:=1..N]: num := nextInt()

runSimulation()

: Simulator : Random

hours := nextInt()

runSimulation()

: Programmer

work( hours )

* [i:=1..N]

eat()


Basic Sequence Diagram Notation(5/5) Iteration over a collection (multiobject)

Messages to class objects

: Sale

* : st := getSubtotal()

t := getTotal()

:SalesLineItem:SalesLineItem

: Foo

list := synchronizedList( aList)message1()

java.util.Collections

not underlined,therefore a class

message to class, or astatic method call


Basic Collaboration Diagram Notation(1/7)

Links

– A connection path between two objects

– Indicates some form of navigation and visibility

– Multiple messages and messages both ways can flow along the same single link

1: makePayment(cashTendered)

2: foo()

2.1: bar(): Register :Sale

link line



Messages

– A sequence number is added to show the sequential order of messages

– Small arrow with each message indicates the direction of the message

– Messages to “self”

1: msg2()2: msg3()3: msg4()

3.1: msg5(): Register :Sale

all messages flow on the same link

msg1()

: Register

msg1()

1: clear()



Creation of instances

1: create(cashier)

: Register :Sale {new}

create message, with optional initializing parameters. This willnormally be interpreted as a constructor call.

<<create>>1: make(cashier)

: Register :Sale {new}

if an unobvious creation message name is used, themessage may be stereotyped for clarity



Message number sequencing

– The first message is not numbered.

– Nesting is denoted by prepending the incoming message number to the outgoing message number

2: makeLineItem(ps, qty)enterItem(id, qty)

1: ps := getSpecification(id)

1.1: ps := get(id)

1.3 [not in specs & specs not full] : put( id, ps)

:Register :Sale

:ProductCatalog

:ProductSpecification

UML notation: note theconditional message syntax

: LocalProducts

IProductsAdapter

1.2 [ not in specs ]:ps := getSpecification(id)

specs

continued in anotherdiagram



Conditional messages

1 [ color = red ] :calculate(): Foo : Bar

message1()

conditional message, with test

1a [test1] : msg2()

:ClassA :ClassB

:ClassC

1a.1:msg3()

msg1()

:ClassD

1b [not test1] : msg4()

1b.1: msg5()

:ClassE

2: msg6()

unconditional aftereither msg2 or msg4 1a and 1b are mutually

exclusive conditional paths



Iteration

Iteration over a collection (multiobject)

1 * [i:=1..N]: num := nextInt(): SimulatorrunSimulation() : Random

iteration is indicated with a * and an optionaliteration clause following the sequence number

1 *: st :=getSubtotal(): Salet := getTotal()

double box indicates a multiobject (collection)

for example, a List object containing manySalesLineItem objects

*:SalesLineItem

:SalesLineItem

these two * symbols used together implyiteration over the multiobject and sending thegetSubtotal message to each member



Messages to a class object

list := synchronizedList( aList ): InstanceOfFoo java.util.Collections

msg1()

not underlined,therefore a class

message to class, or astatic method call

copyright © hsiao-lan wei. 2003 all rights reserved design model interaction diagram

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