UML and WSDL for JISC e-Learning Projects UML

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UML and WSDL for JISC e-Learning ProjectsUML
ADDITIONAL FEATURESRichard Hopkins
rph_at_nesc.ac.ukNeSC Training Team Member
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Goals and Overview

• Goals
• To enable you to appreciate more of UML
• To introduce some features that you might find
  useful
• Overview
• Sequence Diagrams Statecharts
• General Features - Extensibility
• Class Diagrams

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Conditions in Sequence Diags.
Librarian
BC BookCatalogue
JC JournalCatalogue
register(it) Journal
catalogue(it) hardBack
register(it) softBack

• Have different objects for cataloguing books and
  journal
• Journals and softback books are registered
• Hardback books are catalogued

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Statecharts

• Statecharts
• Self Transitions
• Actions
• Alternatives

Action on transition Action1 / Action2 /
isSpoilt / notifyAbuse()
In Bindery
Statechart For Copy Class
On Loan
Return()
On Shelf
not isSpoilt
StatusCheck()
Alternatives decision diamond guards As in
activity diag. (flowchart)
Self-transition
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Statecharts entry / exit actions
Attribute bookBook Invoke its isAvail operation
Borrow() / book . isAvail(self)
On Loan
Statechart For Copy Class
On Shelf
Borrow() / book . notAvail(self)
In Bindery
Rebind() / book . notAvail(self)
Borrow()
On Loan
On Shelf
Borrow()
entry / book . isAvail(self)
exit / book . notAvail(self)
In Bindery
Rebind()

• entry / done whenever enter state
• exit / done whenever exit state
• Clearer and less words

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Sequence Diagrams Statecharts

• Overview
• Sequence Diagrams Statecharts
• General Features - Extensibility
• Class Diagrams

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Stereotypes

• Adding extra classification to model elements
• Pre-defined
• Model-specific
• Already seen some stereotypes

Return Overdue Copy
Use Case Diag. Pre-defined
ltltextendgtgt
ltltincludegtgt
Defer fine
Pay fine
Deployment Diag. Model-specific
ltltInternetgtgt
ltltLANgtgt
UnivServer
ClerksPC
UsersPC

• ltltstereotype namegtgt - written near the element
• Can use for any element icon, line, operation,
  
• Can define a new icon for a particular stereotype
  
• Developing specialised language

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Properties
Book
Title String
author Richard, reviewer David
copiesOnShelf() Integer
isQuery true
getISBN() ISBN
isQuery

• A model element can have a value for a property
  
• isQuery true
• Boolean property values can be written
• X rather than X true
• A way of recording design information
• Tagged value tag is name of property, can be
  omitted if value is unique to property
• Just as a class has an attribute, and object has
  value for it
• So, element type has property, and instance has
  property value
• UML itself is a UML-expressible model

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Pre-defined Properties

• documentation
• Applies to everything
• location
• Applies to most things
• Value is typically a deployment diagram node or
  component
• persistence
• Applies to class, association, attribute
• Whether value survives system re-start
• Value usually Persistent / Transient
• semantics
• Applies to class and operation

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Stereotype vs Property
Class Diag.
Class Diag.
ltltUserAgentLayergtgt ltltInJavagtgt ltltWebServicegtgt Libra
ryService
layerUserAgents, language Java, AWebService
LibraryService
Vs.
ltltComonServiceLayergtgt ltltInCgtgt ltltWebServicegtgt Aut
henticationService
layerCommonService, language C, AWebService
AuthenticationService

• How significant is the characteristic?
• Very Significant (to user) -gt use stereotype
• Being a web service -
• Which layer (since lower layers cant use higher
  ones)
• Relatively incidental -gt use property
• Which language used in implementation

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Class Diagrams

• Overview
• Sequence Diagrams Statecharts
• General Features Extensibility
• Class Diagrams
• Specialised Class vs Attribute
• Interfaces
• Parameterised Classes
• Constraints
• Association Class

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Specialised Class vs Attribute

• Stereotype vs Property
• Like difference between specialised class or
  attribute of general class

Vs.
Book
Book
hardBack bool
HardBackBook
SoftBackBook

• Use specialised class if a significant difference
  to user,
• e.g. hardBack has a reBind operation, but
  softBack doesnt

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Interfaces

• Same concepts as in Java
• A collection of operations
• which must be supported by any class claiming to
  support the interface (match the interface
  realise the interface)
• supports is shown as specialisation with dashed
  arrow
• An interface is like a class but has no instances
  
• no attributes, no associations

Item
Is part of
contains
Article
printOffColour() printOffBW
Journal
ltltinterfacegtgt Copyable
Book
printOffColour() printOffBW
Leaflet
printOffColour() printOffBW
Redundant dont need both
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Interfaces
CopyService
Supports interface lollipop
Copyable
Copyable
(Design) Dependency
Leaflet
Article
Association ( instances can knows about)

• Lollipop dependency asserts that copyService is
  only dependent on the Copyable interface of the
  associated objects
• Other things can have Supports interface
  lollipop use-cases, components

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Parameterised Classes
Alternatively -
T
T
IndexedList
IndexedList
add(t T, pos int) get(pos int) T
add(t T, pos int) get(pos int) T
IndexeddListltBookgt
ltltbindgtgt(Citation)
ltltbindgtgt(Book)
BookLIst
References
IndexedListltCitationgt

• The parameterised class is not really a class
• A function from classes to a class
• Sometimes called a template
• Used to avoid duplication, can be easier to read
• The parameter (T) is almost always used in the
  templates attributes and operations
• It is use of class variable in this way which is
  the point
• Otherwise, could make IndexedList an interface
  supported by both

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Parameterised Classes
T
BIoSystem
ltltbindgtgt(Null)
(Cell)
(Organism)
(Populaton)
(EcoSystem)
Null
Cell
Organism
Population
EcoSystem
BioRegion
1..
BioComponent

• X is a particular kind of Biosystem having Y as
  its constituents

Cell
Organism
Population
EcoSystem
BioRegion

• A BioRegion comprises a collection of EcoSystems,
  comprises a collection of Populations, comprises
  .

• Which is a better model ?

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Association Classes
takes
Student
Module
6
0..
IsTaking
Mark int

• To model there being some information and/or
  operations for an association between two classes
• Could be done using an ordinary class

takes
Student
Module
Student
Module
6
0..
6
0..
1
1
1
1
Or -
0..
0..
6
6
Mark
Mark
Mark int
Mark int

• Less clear
• Would have to implement it in one of these ways

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Constraints
Book
Journal
1
1
Pre-defined constrain type cant be both a copy
of a book and a copy of journal
xor
1..
1..
Copy
braille implies aisle 6
largePrint bool braille bool aisle int shelf
int
Define constraints within an element or between
elements

• A constraint is a condition that must be
  satisfied by any correct implementation.
• These are class invariants
• Can put constraints on other diagram types
• Can be done in natural language or formally in
• Object constraint language (OCL)
• Greater precision
• Harder to understand

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Object Constraint Language
Manager
Worker must contact His/her manger via PA, If
there is one
hasPA Bool phonePhoneNo
1
IF self . lineM . hasPA True THEN self .
lineMphone self . lineM . myPA . Phone
ELSE self . lineMphone self . lineM
. phone
myPA
0..1
Worker
Administrator
phone PhoneNo
lineM Manager lineMphone PhoneNo

• Syntax approximate, see http//www.omg.org/techn
  ology/documents/formal/uml.htm
• Chapt 6
• Other contexts
• Operation pre and post conditions
• State diag., activity diag, sequence diag -Guards

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END - references

• http//www.omg.org/technology/documents/formal/uml
  .htm
• UML Pocket Reference, OReilly,
• ISBN 0-596-00497-4
• UML in a Nutshell
• Using UML Software Engineering with Objects and
  Components, Perdita Stevens with Rob Pooley
• ISBN 0-201-64860-1