Issue 134: Specification of Constraints

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Issue 134 Specification of Constraints

• There is no standard way of specifying
  constraints
• Constraints in MDR metamodel
• OCL expressions can be provided for metaclass and
  its instance
• Target Data Element Concept and Conceptual
  Domain, Value Domain and Data Element and so on.
• Constraints of registered data elements (user
  should be defined)
• Target Conceptual Domain or Value Domain
• Representation, Dimensionality and Classification
  are a kind of constraints
• User defined matadata should enable to be defined
  as extension mechanism, such as ebXML Registry
  and Repository
• Constraint should be described using such user
  defined slots
• Need formal description language such as OCL, CL
• We should allow OCL or other specification
  languages to be used by users of the registry

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Constraints in Data Element Concept

• 4.11.1.3 Data Element Concept
• (1) A Data Element Concept is a concept that can
  be represented in the form of a data element,
  described independently of any particular
  representation.
• (2) A Data Element Concept may have zero or one
  Object Class and zero or one Property.
• (3) The union of a Property and an Object Class
  provides significance beyond either that of the
  Property or the Object Class.
• (4) A Data Element Concept thus has a Definition
  independent from the Definition of the Object
  Class or the Property.
• (5) As an Administered Item, a Data Element
  Concept carries its own Administration Record
  information, allowing it to be identified, named,
  defined and optionally classified within a
  Classification Scheme. IdentifiedandOptionallyClas
  sified
• (6) A Data Element Concept may be associated with
  other Data Element Concepts, via the Data Element
  Concept Relationship.
• (7) The nature of the relationship is described
  using the data element concept relationship type
  description. IsDescribedUsing
• (8) A Data Element Concept may be registered as
  an Administered Item without necessarily being
  associated with any Data Element, but a Data
  Element Concept shall be associated with exactly
  one Conceptual Domain, as represented by the
  "data element concept-conceptual domain
  relationship" in Figure 8. MustBeRegistered,
  ShallBeAssociatedWith
• (9) The Conceptual Domain specifies all valid
  Value Meanings of a Data Element Concept. The
  Conceptual Domain is described in
  4.12.1.1.MustBeContained

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Examples of OCL expression

• MustBeContainedUnless.
• .AttributesCannotBeChanged
• .CannotBeDeleted
• .DependenciesCannotBeChanged
• .NamesMustNotCollide
• .MustNotBeSelf
• .MustBeSame
• .MustNotCollideWith.
• .RuleMustBeObeyed
• No.AllowedFor..

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Examples of Constraints (form MOF1.4)

• A ModelElement that is not a Package must have a
  container. C-1
• The attribute values of a ModelElement which is
  frozen cannot be changed. C-2
• A frozen ModelElement which is in a frozen
  Namespace can only be deleted, by deleting the
  Namespace. C-3
• The link sets that express dependencies of a
  frozen Element on other Elements cannot be
  explicitly changed. C-4
• The names of the contents of a Namespace must
  not collide. C-5
• A Generalizable Element cannot be its own direct
  or indirect supertype. C-6
• A supertypes of a GeneralizableElement must be
  of the same kind as the GeneralizableElement
  itself. C-7
• The names of the contents of a
  GeneralizableElement should not collide with the
  names of the contents of any direct or indirect
  supertype. C-8
• Multiple inheritance must obey the Diamond
  Rule. C-9
• If a Generalizable Element is marked as a
  root, it cannot have any supertypes. C-10
• A GeneralizableElements immediate supertypes
  must all be visible to it. C-11
• A GeneralizableElement cannot inherit from a
  GeneralizableElement defined as a leaf. C-12

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C-1 MustBeContainedUnlessPackage

• format1 MUST_BE_CONTAINED_UNLESS_PACKAGE
• format2 must_be_contained_unless_package
• evaluation policy deferred
• description A ModelElement that is not a Package
  must have a container.

context ModelElement inv not self.oclIsTypeOf(Pac
kage) implies self.container -gt size 1
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C-2 FrozenAttributesCannotBeChanged

• format1 FROZEN_ATTRIBUTES_CANNOT_BE_CHANGED
• format2 frozen_attributes_cannot_be_changed
• evaluation policy immediate
• description The attribute values of a
  ModelElement which is frozen cannot be changed.

context ModelElement inv self.isFrozen()
implies let myTypes self.oclType() -gt
allSupertypes() -gt includes(self.oclType()
) in let myAttrs Set(Attribute)
self.RefBaseObjectrefMetaObject()
-gtasOclType(Class) -gt findElementsByTypeExten
ded(Attribute) in myAttrs -gt forAll(a
self.RefObjectrefValue_at_pre(a)
self.RefObjectrefValue(a))
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C-3 FrozenElementsCannotBeDeleted

• format1 FROZEN_ELEMENTS_CANNOT_BE_DELETED
• format2 frozen_elements_cannot_be_deleted
• evaluation policy immediate
• description A frozen ModelElement which is in a
  frozen Namespace can only be deleted, by deleting
  the Namespace.
• context ModelElement
• post
• (self.isFrozen_at_pre() and
• self.container_at_pre -gt notEmpty and
• self.container.isFrozen_at_pre()) implies
  (self.container.Objectnon_existent() or not
  self.Objectnon_existent())

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C-4 FrozenDependenciesCannotBeChanged

• format1 FROZEN_DEPENDENCIES_CANNOT_BE_CHANGED
• format2 frozen_dependencies_cannot_be_changed
• evaluation policy immediate
• description The link sets that express
  dependencies of a frozen Element on other
  Elements cannot be explicitly changed.
• context ModelElement
• post
• self.isFrozen() implies
• let myClasses self.oclType() -gt allSupertypes()
  -gt includes(self.oclType()) in
• let myRefs Set(Reference)
• self.RefBaseObjectrefMetaObject() -gt
  asOclType(Class) -gt
• findElementsByTypeExtended(Reference) in
• let myDepRefs myRefs -gt
• select(r Setcontents, constraints,
  supertypes, type, referencedEnd,
  exceptions, importedNamespace, elements -gt
  includes(r.name)) in
• myDepRefs -gt forAll(r self.RefObjectrefValue_at_p
  re(r)
• 
  self.RefObjectrefVa
  lue(r))

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C-5 ContentNamesMustNotCollide

• format1 CONTENT_NAMES_MUST_NOT_COLLIDE
• format2 content_names_must_not_collide
• evaluation policy immediate
• description The names of the contents of a
  Namespace must not collide.
• context Namespace
• inv self.contents.forAll( e1, e2 e1.name
  e2.name implies r1 r2)

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C-6 SupertypeMustNotBeSelf

• format1 SUPERTYPE_MUST_NOT_BE_SELF
• format2 supertype_must_not_be_self
• evaluation policy immediate
• description A Generalizable Element cannot be
  its own direct or indirect
• supertype.
• context GeneralizableElement
• inv self.allSupertypes() -gt forAll(s s ltgt
  self)

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C-7 SupertypeKindMustBeSame

• format1 SUPERTYPE_KIND_MUST_BE_SAME
• format2 supertype_kind_must_be_same
• evaluation policy immediate
• description A supertypes of a GeneralizableElemen
  t must be of the same kind as the
  GeneralizableElement itself.
• context GeneralizableElement
• inv self.supertypes -gt forAll(s s.oclType()
  self.oclType())

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C-8 ContentsMustNotCollideWithSupertypes

• format1 CONTENTS_MUST_NOT_COLLIDE_WITH_SUPERTYPES
  
• format2 contents_must_not_collide_with_supertypes
  
• evaluation policy immediate
• description The names of the contents of a
  GeneralizableElement should not
• collide with the names of the contents of any
  direct or indirect
• supertype.
• context GeneralizableElement
• inv
• let superContents self.allSupertypes() -gt
  collect(s s.contents) in
• self.contents -gt forAll(m1 superContents -gt
  forAll(m2 m1.name m2.name implies m1 m2))

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C-9 DiamondRuleMustBeObeyed

• format1 DIAMOND_RULE_MUST_BE_OBEYED
• format2 diamond_rule_must_be_obeyed
• evaluation policy immediate
• description Multiple inheritance must obey the
  Diamond Rule.
• context GeneralizableElement
• inv
• let superNamespaces
• self.supertypes -gt collect(s s.extendedNamespace
  ) in superNamespaces -gt asSet -gt isUnique(s
  s.name)

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C-10 NoSupertypesAllowedForRoot

• format1 NO_SUPERTYPES_ALLOWED_FOR_ROOT
• format2 no_supertypes_allowed_for_root
• evaluation policy immediate
• description If a Generalizable Element is marked
  as a root, it cannot have any supertypes.
• context GeneralizableElement
• inv self.isRoot implies self.supertypes -gt
  isEmpty

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