IfcExternalReferenceRelationship

Item	SPF	XML	Change	Description
IFC2x3 to IFC4
IfcExternalReferenceRelationship			ADDED

Semantic definitions at the entity

Entity definition

IfcExternalReferenceRelationship is a relationship entity that enables objects from the IfcResourceObjectSelect to have the ability to be tagged by external references.

NOTE This relationship is used to assign classification, library or document information to entities that do not inherit from IfcRoot. It has a similar functionality as the subtypes of IfcRelAssociates.

HISTORY New entity in IFC4.

Attribute definitions

#	Attribute	Type	Cardinality	Description	C
3	RelatingReference	IfcExternalReference	[1:1]	An external reference that can be used to tag an object within the range of IfcResourceObjectSelect. NOTE External references can be a library reference (for example a dictionary or a catalogue reference), a classification reference, or a documentation reference.	X
4	RelatedResourceObjects	IfcResourceObjectSelect	S[1:?]	Objects within the list of IfcResourceObjectSelect that can be tagged by an external reference to a dictionary, library, catalogue, classification or documentation.	X

Inherited definitions from supertypes

Entity inheritance

Attribute inheritance

#	Attribute	Type	Cardinality	Description	C
IfcResourceLevelRelationship
1	Name	IfcLabel	[0:1]	A name used to identify or qualify the relationship.	X
2	Description	IfcText	[0:1]	A description that may apply additional information about the relationship.	X
IfcExternalReferenceRelationship
3	RelatingReference	IfcExternalReference	[1:1]	An external reference that can be used to tag an object within the range of IfcResourceObjectSelect. NOTE External references can be a library reference (for example a dictionary or a catalogue reference), a classification reference, or a documentation reference.	X
4	RelatedResourceObjects	IfcResourceObjectSelect	S[1:?]	Objects within the list of IfcResourceObjectSelect that can be tagged by an external reference to a dictionary, library, catalogue, classification or documentation.	X

Formal representations

XSD Specification

 <xs:element name="IfcExternalReferenceRelationship" type="ifc:IfcExternalReferenceRelationship" substitutionGroup="ifc:IfcResourceLevelRelationship" nillable="true"/>

 <xs:complexType name="IfcExternalReferenceRelationship">

  <xs:complexContent>

   <xs:extension base="ifc:IfcResourceLevelRelationship">

    <xs:sequence>

     <xs:element name="RelatingReference" type="ifc:IfcExternalReference" nillable="true"/>

     <xs:element name="RelatedResourceObjects">

      <xs:complexType>

       <xs:group ref="ifc:IfcResourceObjectSelect" maxOccurs="unbounded"/>

       <xs:attribute ref="ifc:itemType" fixed="ifc:IfcResourceObjectSelect"/>

       <xs:attribute ref="ifc:cType" fixed="set"/>

       <xs:attribute ref="ifc:arraySize" use="optional"/>

      </xs:complexType>

     </xs:element>

    </xs:sequence>

   </xs:extension>

  </xs:complexContent>

 </xs:complexType>

EXPRESS Specification


ENTITY IfcExternalReferenceRelationship

 SUBTYPE OF (IfcResourceLevelRelationship);

  RelatingReference : IfcExternalReference;

  RelatedResourceObjects : SET [1:?] OF IfcResourceObjectSelect;

END_ENTITY;

 EXPRESS-G diagram

	Externer Bezug - Relation
	External Reference Relationship