Holt UML Slides

8/12/2019 Holt UML Slides

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Introduction to UML:

Unified Modeling Language

Ric Holt

U Waterloo, March 2009CS246


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2

Example UML ClassDiagram

http://www.agiledata.org/images/oo101ClassDiagram.gif


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UML: Unified Modeling

Language The Unified Modeling Language (UML) is

a family of graphical notations that help

in describing and designing softwaresystems, particularly those built using

object-oriented (OO) style [Martin Fowler

in UML Distilled]


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History

Design notation of various kinds used sinceprogramming began:

Flow charts, Pseudo code, Structure Diagrams

With advent of OO, many conflicting notations(1980s , 1990s)

These notations were combined and unified(late

1990s) UML extensively taught in universities

(2000 - now).


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3 Ways to Use UML

(Both forward & reverse engineering)1) Sketch e.g. at white board

Most common, quick and informal

Communication & understanding2) Blueprint

Detailed design, implemented by programmer

May have tools supporting diagramming3) Programming Language

Tools translate diagrams to executable code


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Fowler says

Almost all the time, my use of the UML is

as sketches.

Im not a fan of detailed forward

engineeredblueprints.

I see the UML as aprogramming language

as a nice idea but doubt that it will ever seesignificant usage.


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Savitch say:

Todays candidate for a graphical

representation formalism is the UML. It

is too early to say whether or not the UMLwill stand the test of time [Savitch,

Absolute C++, 3rd Edition]


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Software Lifecycle:

UML Can Be Used at Various Stages

Analysis: OOA

What is system to do? What services is it to

provide? Provide requirements for designer.

Design: OOD

What will be the parts & structure of the

system? How will they interact? Provideblueprint for programmer.

Programming: OOP


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13 (!!) Kinds of UML Diagrams

1) Activity

2) Class

3) Communication

4) Component

5) Component structure

6) Deployment7) Interaction

8) Object

9) Package

10) Sequence

11) State machine

12) Timing

13) Use case


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Classification of UML Diagrams

(Part 1 of 2)

Structure

1) Class diagram

2) Component diagram (cmpts can be independently purchasedand replaced)

3) Component structure diagram

4) Deployment diagram (what goes on what machine & place)

5) Object diagram6) Package diagram (pkg = group of classes, e.g. namespace)


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Classification of UML Diagrams

(Part 2 of 2)

Behavior

7) Activity diagram (flow chart)

8) Use Case diagram (scenarios for use of system)9) State Machine diagram

10) Sequencediagram

11) Communication diagram (data flow diagrams)

12) Interaction diagram (activity + sequence diagrams)

13) Timing diagram


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Class Diagrams


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Example UML ClassDiagram

http://www.agiledata.org/images/oo101ClassDiagram.gif


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Class

Class Name

Attribute: type

Operation(arg list) : return type

Abstract operation

Various parts are optional


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Instance Specification

(Object)

ObjectName: Class Name

Attribute: type

Operation(arg list) : return type

Abstract operation

Various parts are optional


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Role of A

Role of B

Kinds of Edges

Class A Class B

Source TargetRole name

Client Supplier

Dependency

Navigability

Association

Role name

There are other kinds of edges


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Multiplicities on Edges

(Cardinalities)

1 Exactly one

* Many (any number)

0..1 Optional (zero or one)

m..n Specified range

{ordered}* Ordered


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Generalization

(Inheritance)

Supertype

Subtype 1 Subtype 2


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Note

(Comment)

Comment

about an item

Some

item eg

class


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Sequence Diagrams


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Example for Sequence Diagram

[Fowler]

We have an order and are going to invoke acommand on it to calculate its price. To do

that, the order needs to look at all the lineitems on the order and determine theirprices, which are based on the pricing rulesof the order lines products. Having done

that for all the line items, the order thenneeds to compute an overall discount, whichis based on rules tied to the customer.


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Example for Sequence Diagram

[Fowler]

We have an orderand are going to invoke acommand on it to calculate its price. To do

that, the order needs to look at all the lineitemson the order and determine theirprices, which are based on the pricing rulesof the order linesproducts. Having done

that for all the line items, the order thenneeds to compute an overall discount, whichis based on rules tied to the customer.


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Example Sequence Diagram

anOrder anOrderLine aProduct aCustomer

calculatePricegetQuantity

getProduct

getPricingDetails

getBasePrice

calculateDiscounts

getDiscountInfo

aProductFound

message

Participant Lifeline

Return

Activation

Self call

Message


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Elements of Sequence Diagrams

There is also notation for loops, conditions, etc.

Name: Class

New object

Create

Message

Return

Delete

Self-call


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Diagram Size

(Cognitive Limit)

Generally, a diagram is not useful if it

contains more than about 25 boxes

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Holt UML Slides