Model driven architecture in practice

296 Pages·2007·2.674 MB·English

by  Oscar Pastor, Juan Carlos Molina

Oscar Pastor · Juan Carlos Molina
Model-Driven
Architecture
in Practice
A Software Production Environment
Based on Conceptual Modeling
With48Figuresand35Tables
123
Authors
OscarPastor
DSIC,UniversitadPolitécnicadeValencia
CaminodeVeras/n
46022Valencia,Spain
[email protected]
JuanCarlosMolina
CARETechnologies,S.A.
Pda.MadrigueresSud,44
03700Denia,Spain
LibraryofCongressControlNumber:2007927169
ACMComputingClassification(1998):D.2,I.6,H.1,J.6
ISBN 978-3-540-71867-3 SpringerBerlinHeidelbergNewYork
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©Springer-VerlagBerlinHeidelberg2007
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ToCarmen,OscarandDaniel,ReginaandOscar...
Past,PresentandFutur,alltogethermakingmeeasy
tofacethefascinatingchallengeoflife
OscarPastor
ToBel´en,foreverything.Youenlightenmylife.
Tomyparents,sistersandbrother,forbeingsowonderfulandsupportive.
JuanCarlosMolina
Toeverybody,pastandpresent,atCARETechnologiesandIntegranova.
Youhaveturnedtheideasinthisbookintoasolidworkingreality.
ToJose´MiguelBarbera´,forhisguidanceandcomradeship.
ToSiegfriedBorho,forhisenduringvisionandspirit.
JuanCarlosMolinaandOscarPastor
Contents
PartI TheOO-MethodandSoftwareProductionfromModels
1 Let’sGetPhilosophical.................................................. 3
2 ThePurposeofthisWork ............................................... 7
3 TheNeedforNewDevelopmentEnvironments.......................... 13
3.1 SoftwareDevelopmentToday ...................................... 14
3.1.1 CurrentToolsAreInadequate .............................. 14
3.1.2 DevelopmentProcessesAreNegativelyAffected............ 15
3.2 BetterDevelopmentEnvironmentsAreNeeded .................... 16
4 Object-OrientedModellingastheStartingPoint........................ 19
4.1 TheChosenModel................................................. 19
4.2 KeyAspectsoftheDesiredMethod ................................ 21
4.2.1 CataloguingofConceptualPatterns ........................ 22
4.2.2 EnrichingtheObjectModel................................ 28
4.2.3 SoftwareArchitecture:ArchitecturalPatterns .............. 32
5 TheOO-Method......................................................... 39
5.1 HistoricalBackground............................................. 39
5.2 GeneralFeaturesoftheOO-Method ............................... 42
5.3 OtherApproaches ................................................. 43
PartII ConceptualModelling:AbouttheProblemSpace
6 ConceptualModellingPrimitives ....................................... 49
6.1 ConceptualModelling.TheFourModels........................... 52
VIII Contents
7 ObjectModel............................................................ 55
7.1 Classes ............................................................ 55
7.1.1 Attributes.................................................. 58
7.1.2 Services.................................................... 62
7.1.3 IntegrityConstraints....................................... 73
7.2 RelationshipsBetweenClasses..................................... 75
7.2.1 AgentsandAgentRelationships ............................ 76
7.2.2 Association,Aggregation,andComposition ................ 80
7.2.3 Specialisation .............................................. 95
7.2.4 ParallelComposition....................................... 104
7.2.5 VisibilityBetweenRelatedClasses.......................... 106
7.3 ComplexityManagement .......................................... 111
8 DynamicModel......................................................... 115
8.1 StateTransitionDiagram .......................................... 116
8.1.1 States ...................................................... 117
8.1.2 Transitions................................................. 118
8.1.3 BasicStatechartDiagram .................................. 120
8.1.4 ManagingComplexityinStateTransitionDiagrams........ 121
8.1.5 OperationsandStateTransitionDiagrams ................. 122
8.1.6 SpecialisationandStateTransitionDiagrams............... 123
8.2 ObjectInteractionDiagram........................................ 124
8.2.1 Triggers.................................................... 125
8.2.2 GlobalTransactionsandGlobalOperations ................ 131
9 FunctionalModel ....................................................... 137
9.1 EventEffectSpecificationUsingEvaluations ....................... 139
9.2 EvaluationConditions ............................................. 139
9.3 CategorizationofEvaluations...................................... 141
9.4 CreationEventsandtheFunctionalModel......................... 142
9.5 DestructionEventsandtheFunctionalModel ..................... 144
9.6 SpecialisationandtheFunctionalModel........................... 144
9.7 Transactions,Operations,andtheFunctionalModel ............... 145
10 PresentationModel ..................................................... 147
10.1 GeneralStructure.................................................. 148
10.2 BasicElements..................................................... 151
10.2.1 Entry....................................................... 151
10.2.2 DefinedSelection .......................................... 153
10.2.3 ArgumentGrouping........................................ 155
10.2.4 ArgumentDependency..................................... 157
10.2.5 Filter....................................................... 159
10.2.6 OrderCriterion ............................................ 163
10.2.7 DisplaySet ................................................. 165
10.2.8 Navigation ................................................. 167
Contents IX
10.2.9 Actions..................................................... 169
10.3 InteractionUnits .................................................. 171
10.3.1 ServiceInteractionUnits................................... 172
10.3.2 InstanceInteractionUnit................................... 175
10.3.3 PopulationInteractionUnit ................................ 178
10.3.4 Master/DetailInteractionUnit ............................. 181
10.4 ActionHierarchyTree ............................................. 184
10.4.1 AgentsandActionHierarchyTrees......................... 187
10.5 ConstructingaPresentationModel ................................ 188
11 ConceptualModellingofLegacySystems ............................... 191
11.1 IntroductiontotheConceptofLegacyView ....................... 191
11.2 ObjectModel ...................................................... 192
11.2.1 LegacyViews............................................... 192
11.2.2 Relationships .............................................. 201
11.3 DynamicModel ................................................... 207
11.3.1 StateTransitionDiagrams.................................. 207
11.3.2 ObjectInteractionDiagrams ............................... 208
11.4 FunctionalModel.................................................. 208
11.5 PresentationModel................................................ 209
11.5.1 BasicElements............................................. 209
11.5.2 InteractionUnits........................................... 213
11.5.3 ActionHierarchyTree...................................... 213
12 ConceptualModelValidation ........................................... 215
12.1 Introduction....................................................... 215
12.2 ObjectModel ...................................................... 217
12.2.1 Classes..................................................... 217
12.2.2 RelationshipsBetweenClasses ............................. 221
12.3 DynamicModel ................................................... 223
12.3.1 StateTransitionDiagram................................... 223
12.3.2 ObjectInteractionDiagram ................................ 224
12.4 FunctionalModel.................................................. 224
12.4.1 Evaluations ................................................ 224
12.5 PresentationModel................................................ 225
12.5.1 BasicElements............................................. 225
12.5.2 InteractionUnits........................................... 229
12.5.3 ActionHierarchyTree...................................... 231
X Contents
PartIII ConceptualModelCompilation:fromtheProblemSpacetotheSolution
Space
13 TransformingModelsintoApplications................................. 235
14 RequirementsfortheCompilationofConceptualModels ............... 239
15 ApplicationExecutionStrategy ......................................... 241
15.1 SystemAccess ..................................................... 242
15.2 SystemView ....................................................... 242
15.3 SystemInteraction................................................. 243
15.3.1 ServiceExecution .......................................... 244
15.3.2 QueryExecution ........................................... 255
15.3.3 InteractionUnits........................................... 257
16 ApplicationArchitecture................................................ 261
17 TransformationStrategy ................................................ 265
17.1 Mappings.......................................................... 265
17.2 Transformations................................................... 266
18 BuildingaConceptualModelCompiler ................................. 269
19 IssueswithOtherApproaches........................................... 271
19.1 IssueswithModellingLanguages .................................. 271
19.1.1 LackofAdequacy .......................................... 271
19.1.2 ImpreciseSemantics ....................................... 274
19.1.3 StrongVersusWeakFormalisms............................ 274
19.1.4 LowAbstractionLevel...................................... 275
19.1.5 ActionSemantics........................................... 276
19.1.6 Formulae .................................................. 277
19.1.7 OverspecificationandRedundancy ........................ 277
19.2 IssueswithModelCompilation .................................... 278
19.2.1 LackofanApplicationExecutionStrategy ................. 278
19.2.2 IssueswithApplicationArchitectures ...................... 279
19.2.3 InsufficientTransformations............................... 279
19.3 StateoftheArt..................................................... 280
20 AnalogiesBetweenOO-MethodandMDA............................... 281
20.1 OO-MethodandMDA ............................................. 281
20.2 PropertiesofOO-MethodAbsentfromMDA ...................... 282
21 TheOO-MethodDevelopmentProcess .................................. 285
Contents XI
22 OO-MethodImplementations........................................... 289
22.1 OLIVANOVAModeler ............................................. 289
22.2 OLIVANOVATransformationEngines ............................. 290
Conclusions.................................................................. 293
References ................................................................... 295
Index......................................................................... 301
How this Book Is Organized
Programming technologies have improved continuouslyduring the last decades
but,fromanInformationSystemsperspective,somewell-knownproblemsassoci-
atedwiththedesignandimplementationofanInformationSystemspersist:Object-
Oriented Methods,Formal Specification Languages, Component-Based Software
Production,Aspect-OrientedApproaches.Thisisonlyaveryshortlistoftechnolo-
giesproposedtosolveaveryoldand,atthesametime,verywell-knownproblem:
how to produce software of quality.Programming has been the key task during
the last 40years,and the results have notbeen successfulyet.This bookwill ex-
plore the need of facing a sound software production process from a different
perspective:conceptualmodel-basedsoftwareproduction.Thereareseveralways
torefertothatstrategy.Therearepeopledealingwiththenon-programmingper-
spective where, by non-programming, we mean mainly modelling. Rather than
ExtremeProgramming,theissueisthatanExtremeNon-Programming(Extreme
Modelling-Oriented)approachshouldbetaken.
OtherpeoplefocusonConceptualSchema-CentredSoftwareProduction,based
ontheassumptionthat,todevelopanInformationSystem(IS),itisnecessaryand
sufficienttodefineits Conceptual Schema.This ispresented in(Olive´2005)as a
grandchallenge forInformationSystems Research.This bookisorientedtoface
this challenge, providing concrete solutions.In particular, we will show how to
achievetheobjectiveofgeneratingcodefromahigher-level systemspecification,
normally represented as an Object-Oriented Conceptual Schema. Nowadays,the
interestinMDAhasprovidedanewimpetusforallthesestrategies.Newmethods
proposedifferenttypesofmodeltransformationsthatcoverallthedifferentsteps
ofasoundsoftwareproductionprocessfromanInformationSystemsEngineering
point of view.This must include Organizational Modelling,Requirements Engi-
neering,ConceptualModellingandModel-BasedCodeGenerationtechniques.In
thiscontext,itseemsthatthetimeofModel-TransformationTechnologiesisfinally
here.
Underthepushofthistechnologicalwave,andtakingadvantageofouryearsof
experienceworkingonModel-DrivenDevelopment,wewilldefendthemainidea
that,tohave a softwareproductofquality,the keyskill ismodelling;the issueis
XIV Howthisbookisorganized
that“themodelisthecode”(ratherthan“thecodebeingthemodel”).Considering
this hypothesis, a sound Software Production Process should provide a precise
setofmodels(representingthedifferentlevelsofabstractionofasystemdomain
description),togetherwiththecorrespondingtransformationsfromahigherlevel
of abstraction to the subsequent abstraction level.For instance,a Requirements
Model should be properly transformed into its associated Conceptual Schema,
andthisConceptualSchemashouldbeconvertedintothecorrespondingSoftware
Representation(finalprogram).
Assuming that, behind any programmer decision, there is always a concept,
theproblemtobeproperlyfacedbyanyModel-TransformationTechnologyisthat
of accurately identifying those concepts,together with their associated software
representations.A precise definitionof the set of mappings between conceptual
primitivesorconceptualpatternsandtheircorrespondingsoftwarerepresentations
providesasolidbasisforbuildingConceptualModelCompilers.
Thisiswhatwewish todointhisbook.Ourpreciseobjectiveistoshowhow
anMDA-basedSoftwareProductionEnvironmentbasedonConceptualModelling
canbeputintopractice.Todothis,threemaingoalsneedtobefulfilled.First,the
mainconceptsinvolvedinsuchamethodmustbeproperlyintroduced.Second,how
to constructan adequate Conceptual Modelhas tobe explained indetail.Third,
the processof transformingthe source ConceptualModelintoitscorresponding
SoftwareProductmustbeexplained.Inaccordancewiththesegoals,thestructure
ofthisbookisdividedintothreeparts:
• TheOO-MethodandSoftwareProductionfromModels
• ConceptualModelling:AbouttheProblemSpace
• ConceptualModelCompilation:fromtheProblemSpacetotheSolutionSpace
Now it is time forthe reader to explore how to put all these ideas into practice,
makingConceptualModel-DrivenDevelopmentanaffordabledream.