interaction and design class diagrams

8/10/2019 Interaction and design class diagrams

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Designing with Interactionand Design Class Diagrams

Chapters 15 & 16

Applying UML and Patterns

Craig Larman

With some ideas from

students in George Blanks

course at NJIT


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Two kinds of UML Interaction Diagrams

SequenceDiagrams: show object interactionsarranged in time sequence, vertically

CommunicationDiagrams: show objectinteractions arranged as a flow of objects andtheir links to each other, numerically

Semantically equivalent, structurally different Sequence diagram emphasize time ordering

Communication diagrams make object linkagesexplicit


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Interaction Diagram notation

class instance named instance

:Sale s1:SaleSale

Which would you expect to find most often in Interaction diagrams?

What do you think of :Saleinstead of aSale?


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Sequence diagram notation

: Register : Sale

doA

doB

doX

doC

doD

typicalsychronousmessage

shown with a filled-arrowline

afound messagewhose sender will notbe specified

execution specificationbar indicates focus ofcontrol

Figure 15.7


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What does vertical placement

communicate?

: Register : Sale

makePayment(cashTendered)

: Paymentcreate(cashTendered)

authorize

notethat newlycreatedobjectsareplacedat theircreation"height"

Figure 15.10


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Communication Diagram:

makePayment

1: makePayment(cashTendered)

1.1: create(cashTendered)

:Register :Sale

:Payment


directionof message

Figure 15.4

What do the numbers communicate?

What does a create message communicate?


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Communication

(aka Collaboration) diagrams

Objects are rectangular icons

e.g., Order Entry Window, Order, etc.

Messages are arrows between icons

e.g., prepare()

Numbers on messages indicate sequence

Also spatial layout helps show flow

Which do you prefer: sequence or communication?

Fowler doesnt use communication diagrams

Show flow clearly, but awkward modeling alternatives

UML notation for control logic has changed in UML 2

but Fowler isnt impressed
http://www.cse.lehigh.edu/~glennb/oose/figs/collab5-4.jpghttp://www.cse.lehigh.edu/~glennb/oose/figs/collab5-4.jpghttp://www.cse.lehigh.edu/~glennb/oose/figs/collab5-4.jpghttp://www.cse.lehigh.edu/~glennb/oose/figs/collab5-4.jpghttp://www.cse.lehigh.edu/~glennb/oose/figs/collab5-4.jpg


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Control logic in

Interaction Diagrams

Conditional Message

[ variable = value ]: message() Message is sent only if clause evaluates to true

Iteration (Looping)

* [ i := 1..N ]: message()

* is required; [ ... ] clause is optional

Communication diagrams add Seq. Numbers

before conditional messages or loops


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Logic in sequence diagrams:which notation do you prefer?

calculate

: Bar

yy

xx

[ color =red]opt

: Foo

[ color =red] calculate

: Bar

yy

xx

: Foo

Figure 15.13

Figure 15.14


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Logic in communication diagrams

1[ color =red]: calculate

: Foo : Bar

message1

conditional message, withtest

Figure 15.29


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Loops in sequence diagrams:

which notation do you prefer?

Figure 15.16

Figure 15.17

st =getSubtotal

lineItems[i]:SalesLineItem

t =getTotal

[ i


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Iteration in communication diagrams

1 * [i =1..n]: st =getSubtotal: Sale

t =getTotal

This lifelinebox represents oneinstancefromacollectionof manySalesLineItemobjects.

lineItems[i]is theexpressiontoselect oneelement fromthecollectionof manySalesLineItems;thei valuecomes fromthemessageclause.

lineItems[i]:SalesLineItem

this iterationandrecurrenceclauseindicatesweareloopingacross eachelement of thelineItemscollection.

1 *: st =getSubtotal: Salet =getTotallineItems[i]:

SalesLineItem

Less precise, but usually goodenoughtoimplyiterationacross thecollectionmembers

Figure 15.31


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Asynchronous calls

3: runFinalization:ClockStarter System: Class

startClock

:Clock

1: create

2: run

asynchronousmessage

activeobjectFigure 15.35

Whats the difference between synchronous and asynchronous?

Active object runs in its own thread of execution


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Polymorphism:

How is it shown in interaction diagrams?

:RegisterauthorizedoX

:Payment {abstract}

polymorphicmessage

object inroleof abstractsuperclass

:DebitPayment

authorize

:Foo

stopat thispointdont showanyfurther detailsfor thismessage

separatediagramsfor eachpolymorphicconcretecase

doAdoB

:CreditPayment

authorize

:BardoX

Figure 15.34


15/29

Chapter 16

Design Class Diagrams (DCDs)

During analysis, emphasize domain concepts

During design, shift to software artifacts UML has no explicit notation for DCDs

Uniform UML notation supports smoother

development from analysis to design


16/29

Domain model vs.

Design Class Diagramdifferences?

Register

...

endSale()enterItem(...)makePayment(...)

Sale

timeisComplete: Boolean

/total

makeLineItem(...)

Register

...

Sale

timeisComplete: Boolean

/total

Captures

1

11

DomainModel

conceptualperspective

DesignModel

DCD; softwareperspective

currentSale

Figure 16.2


17/29

Developing a Domain Class Diagram:

the NextGen POS DCD

1) Identify software classes:

Register SaleProductCatalog ProductSpecification

Store SalesLineItem

Payment

2) Begin drawing a class diagram3) Include the attributes from the domain model


18/29

How to show attribute collections?

notice that an association end can optionally alsohave a property string such as {ordered, List}

Sale

time: DateTime

...

SalesLineItem

...

...

1..*

lineItems{ordered, List}

Sale

time: DateTimelineItems : SalesLineItem[1..*]

orlineItems : SalesLineItem[1..*] {ordered}

...

SalesLineItem

...

...

Two ways to showacollection attribute

Figure 16.4


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4) Add method namesfrom interaction diagramsmodel class & interaction diagrams in parallel

: Register : Sale



Register

...

makePayment()

...

Sale

...

makePayment()

...

1

currentSale

messages ininteractiondiagrams indicateoperationsintheclass diagrams classes

identifiedintheinteractiondiagrams aredeclaredintheclass diagrams


20/29

Parameters, return types optional?

readability vs. code generation


21/29

Method body pseudo-code also optional

Register

...

endSale()enterItem(id, qty)makeNewSale()makePayment(cashTendered)

method// pseudo-codeor aspecificlanguageisOKpublicvoidenterItem( id, qty){ProductDescriptiondesc=catalog.getProductDescription(id);sale.makeLineItem(desc, qty);}


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5) Add associations and navigabilityNavigability implies visibility of attributes

How does

navigabilityclarify this

design?

What attribute does

ProductCatalog

implicitly contain?


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6) Adding dependency relationships

Indicates that one element has knowledge of

another element I.e., a change in specification of one thing may

affect another thing that uses it, but not

necessarily the reverse

A dashed directed line

Typically non-attribute visibility between classes


24/29

What does dependency add to this DCD?

SalesLineItem

...

...

ProductDescription

...

...

1..*lineItems

Sale

...

updatePriceFor( ProductDescription)

...

theSalehas parameter visibility toaProductDescription, andthus somekindofdependency


25/29

Composition (whole-part) relations

Finger0..7

Hand

composition

1

Square40

Board1

SalesLineIte1..*

Sale1

compositionmeans

-apart instance(Square) canonlybepart of onecomposite(Board) at atime

-thecompositehassoleresponsibilityfor managemitsparts, especiallycreationanddeletion

Figure 16.13


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Association classes

model association with attributes & operations

salary

startDate

Employment

EmploysCompany Person**

apersonmayhaveemployment withseveralcompanies

Figure 16.16


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interfaceList

clear()

...

Kparameterizedor templateinterfacesandclasses

Kisatemplateparameter

anonymousclasswith

templatebindingcomplete

Board

squares: List

orsquares: List

...

ArrayList

clear()...

theattributetypemaybeexpressedin

official UML, withthetemplatebinding

syntaxrequiringanarrow

orinanother language, suchasJava

ArrayList

elements: T[*]...

clear()

...

T

for example, theelementsattributeisanarrayof typeT, parameterizedandboundbeforeactual use.

thereisachancetheUML2arrow symbol will

eventuallybereplacedwithsomethingelsee.g.,=

Interfaces and Template ClassesInterface is a predefined stereotype

Templates take parameters in corner

Figure 16.18

o f f i c ia l l y i n U M L t h e t o p f o r m a t i s


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DCD

summary

Questions?

ja v a .a w t: :F o n t

o rja v a .a w t. F o n t

p l a in : In t = 0 { r e a d O n l y }b o ld : I nt = 1 { r ea d O n l y }n a m e : S t r i n gs t y l e : I n t = 0.. .

g e t F o n t ( n a m e : S t ri n g ) : F o n tg e tN a m e ( ) : S t ri n g

.. .

i n t e r f a c e R u n n a b l e

r u n ( )

- e l li p s is m e a n s t h e r e m a y b e e l e m e n t s , b u t n o t s h o w n

- a b l a n k c o m p a r t m e n t o f fi c ia l ly m e a n s u n k n o w n b u t a s ac o n v e n t i o n w i ll b e u s e d t o m e a n n o m e m b e r s

S u b c l a s s F o o

.. .

r u n ( ).. .

S u p e r c l a s s F o oo r

S u p e r C l a s s F o o { a b s t r a c t }

- c l a s s O r S t a t ic A t t r ib u t e : I n t+ p u b l i c A t t r ib u t e : S t r in g- p r iv a t e A t t ri b u tea s s u m e d P r i v a t e A t t r i b u t ei s I n i ti a l iz e d A t t ri b u t e : B o o l = t r u e

a C o l l e c t io n : V e g g i e B u r g e r [ * ]a t t r i b u t e M a y L e g a l l y B e N u l l : S t r i n g [ 0 . . 1 ]f i n a l C o n s t a n t A t t r ib u t e : In t = 5 { re a d O n l y }

/d e ri v e d A tt ri b u te

+ c l a s s O r S t a t ic M e t h o d ( )+ p u b l i c M e t h o d ( )a s s u m e d P u b l i c M e t h o d ( )- p r iv a t eM e t h o d ( )# p r o t e c te d M e t h o d ( )~ p a c k a g e V i s i b l e M e t h o d ( )

c o n s t r u c to r S u p e r c l a s s F o o ( L o n g )m e t h o d W i th P a r m s ( p a r m 1 : S t r in g , p a r m 2 : F l o a t)m e t h o d R e t u r n s S o m e t h i n g ( ) : V e g g i e B u r g e rm e t h o d T h r o w s E x c e p t i o n ( ) { e x c e p t i o n I O E x c e p t i o n }a b s t ra c t M e t h o d ( )a b s t r a c t M e t h o d 2 ( ) { a b s t r a c t } / / a l t e r n a t ef i n a l M e t h o d ( ) { l e a f } / / n o o v e r r i d e i n s u b c l a s ss y n c h r o n i z e d M e t h o d ( ) { g u a r d e d }

3 c o m m o nco m p a r t m e n t s

1 . c l a s s i f ie r n a m e

2 . a t t r i b u t e s

3 . o p e r a t i o n s

i n t e r f a c ei m p l e m e n t a t i o na n ds u b c l a s s i n g

F r u i t

.. .

.. .

P u r c h a s e O r d e r

.. .

.. .

1

a s s o c i a t i o n w i t hmu l t i p l i c i t i e s

d e p e n d e n c y

o f f i c ia l l y i n U M L , t h e t o p f o r m a t i su s e d t o d i s ti n g u i s h t h e p a c k a g en a m e f ro m t h e c la s s n a m e

u n o f f i c i a l ly , t h e s e c o n d a l t e r n a t i v ei s c o m m o n

o r d e r

a n i n t e r f a c es h o w n w i th ak e y w o r d

Figure 16.1


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Designing with interaction

and class diagrams

Beginners often emphasize Class diagrams

Interaction diagrams deserve more attention Some tools can help:

Convert between sequence and communication

diagrams automatically

Reflect changes in class and interaction diagramsin parallel

interaction and design class diagrams

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