OBJECT CONSTRAINT LANGUAGE OCL. Tomáš Černý : Object contraint language

Transcription

1 OBJECT CONSTRAINT LANGUAGE OCL Tomáš Čerý : Object cotrait laguage

2 OCL INTRO Flight Airplae type : eum of cargo, passeger flights type : eum of cargo, passeger {cotext Flight iv: type = #cargo implies airplae.type = #cargo iv: type = #passeger implies airplae.type = #passeger} Tomáš Čerý : Object cotrait laguage 2

3 OCL INTRO Flight Airplae type : eum of cargo, passeger flights type : eum of cargo, passeger {cotext Flight iv: type = #cargo implies airplae.type = #cargo iv: type = #passeger implies airplae.type = #passeger} Tomáš Čerý : Object cotrait laguage 3

4 OCL INTRO Flight Airplae type : eum of cargo, passeger flights type : eum of cargo, passeger {cotext Flight iv: type = #cargo implies airplae.type = #cargo iv: type = #passeger implies airplae.type = #passeger} Always true Tomáš Čerý : Object cotrait laguage 4

5 OCL INTRO Flight Airplae type : eum of cargo, passeger flights type : eum of cargo, passeger {cotext Flight iv: type = #cargo implies airplae.type = #cargo iv: type = #passeger implies airplae.type = #passeger} Tomáš Čerý : Object cotrait laguage 5

6 OCL INTRO II Airport ame: Strig cotext Flight origi destiatio departig Flights iv: origi <> destiatio * * arrivig Flights Flight departtime: Time /arrivaltime: Time duratio : Iterval maxnrpassegers: Iteger Airlie ame:strig flights airlie iv: origi.ame = Amsterdam cotext Flight iv: airlie.ame = KLM Tomáš Čerý : Object cotrait laguage 6

7 OCL INTRO II Airport ame: Strig cotext Flight origi destiatio departig Flights iv: origi <> destiatio * * arrivig Flights Flight departtime: Time /arrivaltime: Time duratio : Iterval maxnrpassegers: Iteger Airlie ame:strig flights airlie iv: origi.ame = Amsterdam cotext Flight iv: airlie.ame = KLM iv: airlie.ame.tolower = klm Tomáš Čerý : Object cotrait laguage 7

8 OCL INTRO III cotext Perso iv: if employer.ame = CVUT the job.type = #lecturer else job.type = #programmer edif Job type : {lecturer, programmer} Perso * employee employer Compay ame : Strig Tomáš Čerý : Object cotrait laguage 8

9 DEFINITION OF CONSTRAINT A costrait is a restrictio o oe or more values of (part of) a object-orieted model or system. Tomáš Čerý : Object cotrait laguage 9

10 HISTORY 995 IBEL IBM Součást UML. Tomáš Čerý : Object cotrait laguage 0

11 UML DIAGRAM NEDOSTAČUJE Potřebujeme jazyk pro specifikaci Potřebujeme ěco pro Objektový ávrh e ový jazyk Potřebujeme ěco stadardizovaého Tomáš Čerý : Object cotrait laguage

12 ÚČEL OCL Jazyk formálí specifikace -> implemetovatelý Objektový ávrh Ituitiví sytax pro OO jazyk Pozor eí to programovací jazyk! Tomáš Čerý : Object cotrait laguage 2

13 VÝHODY FORMÁLNÍ SPECIFIKACE Lepší dokumetace Omezeí modelu Iformace avíc Přesost Zamezí dvojzačosti Komuikace bez edorozuměí Komuikace mezi vývojářem a aalytikem bez edorozuměí Tomáš Čerý : Object cotrait laguage 3

14 KAM S OCL Specifikace ivariatů tříd a typů Co smí a co e Vymezeí legálích hodot Pre- a post-coditios pro metody Navigačí jazyk Omezeí/vymezeí operací Test požadavku a specifikace Tomáš Čerý : Object cotrait laguage 4

15 EXAMPLE: A MORTGAGE SYSTEM (HYPOTEKA). A perso may have a mortgage oly o a house she ows. 2. The start date of a mortgage is before its ed date. Tomáš Čerý : Object cotrait laguage 5

16 OCL SPECIFICATION OF THE CONSTRAINTS:. cotext Mortgage cotext Mortgage ivariat: self.security.ower = self.borrower ivariat: security.ower = borrower 2. cotext Mortgage cotext Mortgage ivariat: self.startdate < self.eddate ivariat: startdate < eddate. A perso may have a mortgage oly o a house she ows. 2. The start date of a mortgage is before its ed date. Tomáš Čerý : Object cotrait laguage 6

17 OCL SPECIFICATION OF THE CONSTRAINTS:. cotext Mortgage cotext Mortgage ivariat: self.security.ower = self.borrower ivariat: security.ower = borrower 2. cotext Mortgage cotext Mortgage ivariat: self.startdate < self.eddate ivariat: startdate < eddate Tomáš Čerý : Object cotrait laguage 7

18 OCL SPECIFICATION OF THE CONSTRAINTS:. cotext Mortgage cotext Mortgage ivariat: self.security.ower = self.borrower ivariat: security.ower = borrower 2. cotext Mortgage cotext Mortgage ivariat: self.startdate < self.eddate ivariat: startdate < eddate Tomáš Čerý : Object cotrait laguage 8

19 OCL SPECIFICATION OF THE CONSTRAINTS:. cotext Mortgage cotext Mortgage ivariat: self.security.ower = self.borrower ivariat: security.ower = borrower 2. cotext Mortgage cotext Mortgage ivariat: self.startdate < self.eddate ivariat: startdate < eddate Tomáš Čerý : Object cotrait laguage 9

20 OCL SPECIFICATION OF THE CONSTRAINTS:. cotext Mortgage cotext Mortgage ivariat: self.security.ower = self.borrower ivariat: security.ower = borrower 2. cotext Mortgage cotext Mortgage ivariat: self.startdate < self.eddate ivariat: startdate < eddate Tomáš Čerý : Object cotrait laguage 20

21 OCL SPECIFICATION OF THE CONSTRAINTS:. cotext Mortgage cotext Mortgage ivariat: self.security.ower = self.borrower ivariat: security.ower = borrower 2. cotext Mortgage cotext Mortgage ivariat: self.startdate < self.eddate ivariat: startdate < eddate Tomáš Čerý : Object cotrait laguage 2

22 MORE CONSTRAINTS EXAMPLES All players must be over 8. cotext Player ivariat: self.age >=8 Player age: Iteger The umber of guests i each room does t exceed the umber of beds i the room. room guest Room Guest * umberofbeds: Iteger cotext Room ivariat: guest -> size() <= umberofbeds Tomáš Čerý : Object cotrait laguage 22

23 CONSTRAINTS/OMEZENÍ (INVARIANTS), CONTEXTS AND SELF Costrait (ivariat) Boolea OCL výraz vyhodotitelý do true/false Každý costrait je vázá a specifický typ (class, associatio class, iterface) v UML modelu Má svůj cotext. Cotext objektu může být vytiče přes keyword self. Cotext lze specifikovat přes: q q Cotext <cotext ame> Přerušovaou čárou spojující objekt v UML modelu Costrait může mít ázev za klíčovým slovem ivariat. Tomáš Čerý : Object cotrait laguage 23

24 ProgramParter umberofcustomers: Iteger deliveredservices Service coditio: Boolea poitseared: Iteger poitsbured: Iteger descriptio: Strig Date..* parter geeratedby $ow: Date parters isbefore(t:date): Boolea isafter(t:date): Boolea =(t:date): Boolea..* {ordered}..* Tomáš Čerý : Object cotrait laguage LoyaltyProgram eroll(c:customer) ServiceLevel ame: Strig level availableservices trasactios program actuallevel LoyaltyAccout poits: Iteger Membership 0.. ear(i: Iteger) bur(i: Iteger) isempty(): Boolea trasactios Trasactio poits: Iteger date:date accout program(): LoyaltyProgram Burig Earig card trasactios Customer ame: Strig title:strig ismale: Boolea dateofbirth: Date age(): Iteger ower card CustomerCard valid: Boolea validform: Date goodthru: Date color: eum{silver, gold} pritedname: Strig card 24

25 USING OCL IN CLASS DIAGRAMS <<precoditio>> i >= 0 LoyaltyAccout poits: Iteger ear(i: Iteger) bur(i: Iteger) isempty(): Boolea class ivariat { poits >= 0 } <<precoditio>> poits >= i ad i >= 0 precoditio for bur operatio <<postcoditio>> poits = poits@pre + i <<postcoditio>> result = (poits=0) <<postcoditio>> poits = poits@pre - i postcoditio for bur operatio Tomáš Čerý : Object cotrait laguage 25

26 Ivariaty Atributů Ivariaty atributů: cotext Customer ivariat age-restrictio: age >= 8 cotext CustomerCard ivariat correctdates: validfrom.isbefore(goodthru) The type of validfrom ad goodthru is Date. isbefore(date):boolea is a Date operatio. Customer ame: Strig title:strig ismale: Boolea dateofbirth: Date age(): Iteger ower card CustomerCard valid: Boolea validform: Date goodthru: Date color: eum{silver, gold} pritedname: Strig The class o which the ivariat must be put is the ivariat cotext. For the above example, this meas that the expressio is a ivariat of the Customer class. Tomáš Čerý : Object cotrait laguage 26

27 Ivariaty : Navigace přes associace role Navigatio over associatios is used to refer to Associated objects, startig from the cotext object: cotext CustomerCard ivariat: ower.age >= 8 ower à a Customer istace. ower.age à a Iteger. Customer ame: Strig title:strig ismale: Boolea dateofbirth: Date age(): Iteger CustomerCard valid: Boolea validform: Date goodthru: Date color: eum{silver, gold} pritedname: Strig Note: This is ot the right cotext for this costrait! If the role ame is missig use the class ame at the other ed of the associatio, startig with a lowercase letter. Preferred: Always give role ames. ower card Tomáš Čerý : Object cotrait laguage 27

28 Ivariaty : Navigace přes associace roles cotext CustomerCard ivariat pritedname: pritedname = ower.title.cocat( ).cocat(ower.ame) pritedname à a Strig. ower à a Customer istace. ower.title à a Strig. ower.ame à a Strig. Strig is a recogized OCL type. cocat is a Strig operatio, with the sigature cocat(strig): Strig. Tomáš Čerý : Object cotrait laguage 28

29 ProgramParter umberofcustomers: Iteger deliveredservices Service coditio: Boolea poitseared: Iteger poitsbured: Iteger descriptio: Strig Date..* parter geeratedby $ow: Date parters isbefore(t:date): Boolea isafter(t:date): Boolea =(t:date): Boolea..* {ordered}..* Tomáš Čerý : Object cotrait laguage LoyaltyProgram eroll(c:customer) ServiceLevel ame: Strig level availableservices trasactios program actuallevel LoyaltyAccout poits: Iteger Membership 0.. ear(i: Iteger) bur(i: Iteger) isempty(): Boolea trasactios Trasactio poits: Iteger date:date accout program(): LoyaltyProgram Burig Earig card trasactios Customer ame: Strig title:strig ismale: Boolea dateofbirth: Date age(): Iteger ower cards CustomerCard valid: Boolea validform: Date goodthru: Date color: eum{silver, gold} pritedname: Strig card 29

30 Ivariaty : Navigace přes associace Navigatio from a class through a associatio class uses the associatio class ame to obtai all tuples of a object: The cards of the memberships of a customer are oly the customer s cards : cotext Customer ivariat correctcard: cards->icludesall(membership.card) This is exactly the same as the previous costrait: The ower of the card of a membership must be the customer i the membership : cotext Membership ivariat correctcard: card.ower = customer The Membership correctcard costrait is better! Tomáš Čerý : Object cotrait laguage 30

31 Ivariats usig Navigatio through Associatios with May Multiplicity Navigatio over associatios roles with multiplicity greater tha yields a Collectio type. Operatios o collectios are accessed usig a arrow ->, followed by the operatio ame. A customer card belogs oly to a membership of its ower : cotext CustomerCard ivariat correctcard: ower.membership->icludes(membership) ower à a Customer istace. ower.membership à a set of Membership istaces. membership à a Membership istace. icludes is a operatio of the OCL Collectio type. Tomáš Čerý : Object cotrait laguage 3

32 NAVIGATING TO COLLECTIONS Customer Accout Trasactio cotext Customer accout produces a set of Accouts cotext Customer accout.trasactio produces a bag of trasactios If we wat to use this as a set we have to do the followig accout.trasactio -> asset Tomáš Čerý : Object cotrait laguage 32

33 ProgramParter umberofcustomers: Iteger deliveredservices Service coditio: Boolea poitseared: Iteger poitsbured: Iteger descriptio: Strig Date..* parter geeratedby $ow: Date parters isbefore(t:date): Boolea isafter(t:date): Boolea =(t:date): Boolea..* {ordered}..* Tomáš Čerý : Object cotrait laguage LoyaltyProgram eroll(c:customer) ServiceLevel ame: Strig level availableservices trasactios program actuallevel LoyaltyAccout poits: Iteger Membership 0.. ear(i: Iteger) bur(i: Iteger) isempty(): Boolea trasactios Trasactio poits: Iteger date:date accout program(): LoyaltyProgram Burig Earig card trasactios Customer ame: Strig title:strig ismale: Boolea dateofbirth: Date age(): Iteger ower cards CustomerCard valid: Boolea validform: Date goodthru: Date color: eum{silver, gold} pritedname: Strig card 33

34 Navigatio to Collectios The parters of a loyalty program have at least oe delivered service : cotext LoyaltyProgram ivariat miservices: parters.deliveredservices->size() >= The umber of a customer s programs is equal to that of his/her valid cards : cotext Customer ivariat sizesagree: Programs->size() = cards->select(valid=true)->size() Tomáš Čerý : Object cotrait laguage 34

35 Navigatio to Collectios Whe a loyalty program does ot offer the possibility to ear or bur poits, the members of the loyalty program do ot have loyalty accouts. That is, the loyalty accouts associated with the Memberships must be empty : cotext LoyaltyProgram ivariat oaccouts: parters.deliveredservices-> forall(poitseared = 0 ad poitsbured = 0) implies Membership.accout->isEmpty() ad, or, ot, implies, xor are logical coectives. Tomáš Čerý : Object cotrait laguage 35

36 THE OCL COLLECTION TYPES Collectio is a predefied OCL type q Operatios are defied for collectios q They ever chage the origial Three differet collectios: q q q Set (o duplicates) Bag (duplicates allowed) Sequece (ordered Bag) With collectios type, a OCL expressio either states a fact about all objects i the collectio or states a fact about the collectio itself, e.g. the size of the collectio. Sytax: q collectio->operatio Tomáš Čerý : Object cotrait laguage 36

37 COLLECTION OPERATIONS <collectio> size ( ) isempty ( ) otempty ( ) sum ( ) cout ( object ) icludes ( object ) icludesall ( collectio ) Tomáš Čerý : Object cotrait laguage 37

38 COLLECTIONS CONT. <collectio> select ( e:t <b.e.>) reject ( e:t <b.e.>) collect ( e:t <v.e.>) forall ( e:t* <b.e.>) exists ( e:t <b.e.>) iterate ( e:t ; r:t 2 = <v.e.> <v.e.>) b.e. stads for: boolea expressio v.e. stads for: value expressio Tomáš Čerý : Object cotrait laguage 38

39 CHANGING THE CONTEXT Customer ame:strig title: Strig golduser: Boolea age( ):Iteger ower..* cards StoreCard pritname:strig poits: Iteger ear(p:iteger) cotext StoreCard ivariat: pritname = ower.title.cocat(ower.ame) cotext Customer cards forall ( pritname = ower.title.cocat(ower.ame) ) Tomáš Čerý : Object cotrait laguage 39

40 EXAMPLE UML DIAGRAM Studet ame: Strig take_by submitted_by..* submits takes..* Module code: Strig credit: Iteger for_module set_work..* Assessmet weight: Iteger Exam hours: Iteger Coursework date: Strig Tomáš Čerý : Object cotrait laguage 40

41 CONSTRAINTS a) Modules ca be take iff they have more tha seve studets registered b) The assessmets for a module must total 00% c) Studets must register for 20 credits each year d) Studets must take at least 90 credits of CS modules each year e) All modules must have at least oe assessmet worth over 50% f) Studets ca oly have assessmets for modules which they are takig Tomáš Čerý : Object cotrait laguage 4

42 CONSTRAINT (A) Modules ca be take iff they have more tha seve studets registered Note: whe should such a costrait be imposed? cotext Module ivariat: take_by size > 7 Tomáš Čerý : Object cotrait laguage 42

43 CONSTRAINT (B) The assessmets for a module must total 00% cotext Module ivariat: set_work.weight sum( ) = 00 Tomáš Čerý : Object cotrait laguage 43

44 CONSTRAINT (C) Studets must register for 20 credits each year cotext Studet ivariat: takes.credit sum( ) = 20 Tomáš Čerý : Object cotrait laguage 44

45 CONSTRAINT (D) Studets must take at least 90 credits of CS modules each year cotext Studet ivariat: takes select(code.substrig(,2) = CS ).credit sum( ) >= 90 Tomáš Čerý : Object cotrait laguage 45

46 CONSTRAINT (E) All modules must have at least oe assessmet worth over 50% cotext Module ivariat: set_work exists(weight > 50) Tomáš Čerý : Object cotrait laguage 46

47 CONSTRAINT (F) Studets ca oly have assessmets for modules which they are takig cotext Studet ivariat: takes icludesall(submits.for_module) Tomáš Čerý : Object cotrait laguage 47

48 OCL CONSTRAINTS A costrait is a restrictio o oe or more values of (part of) a object model/system. Costraits come i differet forms: q q q q ivariat costrait o a class or type that must always hold pre-coditio costrait that must hold before the executio of a op. post-coditio costrait that must hold after the executio of a op. guard costrait o the trasitio from oe state to aother. We studied oly class costraits (ivariats). Tomáš Čerý : Object cotrait laguage 48

49 FURTHER RESOURCES FOR OCL The Object Costrait Laguage ISBN OCL home page Tomáš Čerý : Object cotrait laguage 49

50 FURTHER RESOURCES FOR OCL The Amsterdam Maifesto o OCL I Object Modelig with the OCL (LNCS2263) p5-49 The Object Costrait Laguage, Precise Modelig with UML, Addiso-Wesley, 999. The Object Costrait Laguage, Precise Modelig with UML 2d Respose to the UML 2.0 OCL RfP (ad/ ) Revised Submissio, Versio.6 Jauary 6, 2003 Some Shortcomigs of OCL, the Object Costrait Laguage of UML Madaa Vaziri ad Daiel Jackso,999 UML CENTER Iformal formality? The Object Costrait Laguage ad its applicatio i the UML metamodel Aeke Kleppe, Jos Warmer, Steve Cook A Pratical Applicatio of the Object Costrait Laguage OCL Kjetil Moage The UML's Object Costrait Laguage: OCL Specifyig Compoets, JAOO Tutorial September 2000 Jos Warmer & Aeke Kleppe Tomáš Čerý : Object cotrait laguage 50