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IfcConstraint

Definition from IAI: The class IfcConstraint is used to define general information appropriate for all constraints. It is referenced by IfcConstraintUsage in IfcControlExtension schema, and thereby can be related to IfcObjects through appropriate objectified relationhip declared in IfcKernel schema.

HISTORY New Entity in IFC Release 2.0
ISSUE See issue and change log for changes made in IFC 2x.

EXPRESS specification:

ENTITY IfcConstraint
SUPERTYPE OF (ONEOF(IfcMetric, IfcObjective));
ConstraintGrade  :  IfcConstraintEnum;
Description  :  OPTIONAL IfcText;
ConstraintSource  :  OPTIONAL IfcLabel;
Name  :  IfcLabel;
CreatingActor  :  OPTIONAL IfcActorSelect;
CreationTime  :  OPTIONAL IfcDateTimeSelect;
INVERSE
Aggregates  :  SET OF IfcConstraintAggregationRelationship FOR RelatingConstraint;
IsAggregatedIn  :  SET OF IfcConstraintAggregationRelationship FOR RelatedConstraints;
WHERE
WR11  :  NOT(ConstraintGrade = IfcConstraintEnum.USERDEFINED) OR EXISTS(Description) OR EXISTS(ConstraintSource);
END_ENTITY;

Attribute definitions:

ConstraintGrade  :  Enumeration that qualifies the type of constraint.
Description  :  A textual description of the constraint.
ConstraintSource  :  Any source material, such as a code or standard, from which the constraint originated.
Name  :  A name to be used for the constraint (e.g., ChillerCoefficientOfPerformance).
CreatingActor  :  Person and/or organization that has created the constraint.
CreationTime  :  Time when information specifying the constraint instance was created.
Aggregates  :  Reference to the relationships that collect other constraints into this aggregate constraint.
IsAggregatedIn  :  Reference to the relationships that relate this constraint into aggregate constraints.

Formal Propositions:

WR11  :  When ConstriantGrade is set to be UserDefined, constraint shall be qualified by Description or ConstraintSource.

References (4):

Name Type Referred through Express-G
IfcConstraintAggregationRelationship Entity
Attribute 'RelatingConstraint'
Attribute 'RelatedConstraints'
Diagram 1
IfcMetric Entity
Supertype
Diagram 1
IfcObjective Entity
Supertype
Diagram 1

Inheritance graph

ENTITY IfcConstraint;
ENTITY IfcConstraint;
ConstraintGrade  :  IfcConstraintEnum;
Description  :  OPTIONAL IfcText;
ConstraintSource  :  OPTIONAL IfcLabel;
Name  :  IfcLabel;
CreatingActor  :  OPTIONAL IfcActorSelect;
CreationTime  :  OPTIONAL IfcDateTimeSelect;
INVERSE
Aggregates  :  SET OF IfcConstraintAggregationRelationship FOR RelatingConstraint;
IsAggregatedIn  :  SET OF IfcConstraintAggregationRelationship FOR RelatedConstraints;
END_ENTITY;