5.1.3.15 IfcPropertySetDefinition

Définition d'ensemble de propriété
Definition der Merkmalliste (allgemein)

IfcPropertySetDefinition is a generalization of all individual property sets that can be assigned to an object or type object. The property set definition can be either:

Dynamically extendable property sets - IfcPropertySet, a set of properties for which the IFC model only provides a kind of "meta model", to be further declared by agreement. This means no entity definition of the properties exists within the IFC model. The declaration is done by assigning a significant string value to the Name attribute of the entity as defined in the entity IfcPropertySet and at each subtype of IfcProperty, referenced by the property set. Dynamically defined property sets may have an underlying template provided by IfcPropertySetTemplate.

Statically defined property sets - IfcPreDefinedPropertySet, a property set entity that exists within the IFC specification. The semantic meaning of each statically defined property set is declared by its entity type and the meaning of the properties is defined by the name and data type of the explicit attribute representing it.

HISTORY  New entity in IFC2x
IFC4 CHANGE  The subtype IfcPreDefinedPropertySet has been added.

Relationship use definition

Property set definitions define information that is shared among multiple instances of objects, either object occurrences or object types. IfcPropertySetDefinition's (by their instantiable subtypes) can participate within the following relationships:

NOTE  Properties assigned to object occurrences may override properties assigned to the object type. See IfcRelDefinesByType for further information.

XSD Specification:

 <xs:element name="IfcPropertySetDefinition" type="ifc:IfcPropertySetDefinition" abstract="true" substitutionGroup="ifc:IfcPropertyDefinition" nillable="true"/>
 <xs:complexType name="IfcPropertySetDefinition" abstract="true">
  <xs:complexContent>
   <xs:extension base="ifc:IfcPropertyDefinition"/>
  </xs:complexContent>
 </xs:complexType>

EXPRESS Specification:

ENTITY IfcPropertySetDefinition
ABSTRACT SUPERTYPE OF(ONEOF(IfcPreDefinedPropertySet, IfcPropertySet, IfcQuantitySet))
SUBTYPE OF IfcPropertyDefinition;
INVERSE
DefinesType : SET OF IfcTypeObject FOR HasPropertySets;
IsDefinedBy : SET OF IfcRelDefinesByTemplate FOR RelatedPropertySets;
DefinesOccurrence : SET [0:1] OF IfcRelDefinesByProperties FOR RelatingPropertyDefinition;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

Attribute Definitions:

DefinesType : The type object to which the property set is assigned. The property set acts as a shared property set to all occurrences of the type object.
NOTE  The relationship between the IfcPropertySetDefinition and the IfcTypeObject is a direct relationship, not utilizing IfcRelDefinesByProperties, for maintaining compatibility with earlier releases of this standard.
IFC4 CHANGE  The cardinality has been changed from 0:1 to 0:? with upward compatibility for file based exchange.
IsDefinedBy : Relation to the property set template, via the objectified relationship IfcRelDefinesByTemplate, that, if given, provides the definition template for the property set or quantity set and its properties.
IFC4 CHANGE  New inverse relationship, change made with upward compatibility for file based exchange.
DefinesOccurrence : Reference to the relation to one or many object occurrences that are characterized by the property set definition. A single property set can be assigned to multiple object occurrences using the objectified relationship IfcRefDefinesByProperties.
IFC4 CHANGE Inverse attribute renamed from PropertyDefinitionOf with upward compatibility for file-based exchange.

Inheritance Graph:

ENTITY IfcPropertySetDefinition
ENTITY IfcRoot
GlobalId : IfcGloballyUniqueId;
OwnerHistory : OPTIONAL IfcOwnerHistory;
Name : OPTIONAL IfcLabel;
Description : OPTIONAL IfcText;
ENTITY IfcPropertyDefinition
INVERSE
HasContext : SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions;
HasAssociations : SET OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcPropertySetDefinition
INVERSE
DefinesType : SET OF IfcTypeObject FOR HasPropertySets;
IsDefinedBy : SET OF IfcRelDefinesByTemplate FOR RelatedPropertySets;
DefinesOccurrence : SET [0:1] OF IfcRelDefinesByProperties FOR RelatingPropertyDefinition;
END_ENTITY;

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