IfcLibraryReference

Natural language names
Bibliothekseintrag
Library Reference
Référence de bibliothèque
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4 4.0.0.0
    IfcLibraryReference
      LocationMODIFIEDType changed from IfcLabel to IfcURIReference.
      IdentificationXMODIFIEDName changed from ItemReference to Identification.
      DescriptionADDED
      LanguageADDED
      ReferencedLibraryADDED
Semantic definitions at the entity
Entity definition

An IfcLibraryReference is a reference into a library of information by Location (provided as a URI). It also provides an optional inherited Identification key to allow more specific references to library sections or tables. The inherited Name attribute allows for a human interpretable identification of the library item. Also, general information on the library from which the reference is taken, is given by the ReferencedLibrary relation which identifies the relevant occurrence of IfcLibraryInformation.

The ifcLibraryReference additionally provides the capability to handle multilingual library entries. The Language attribute then holds the language tag for the language used by the strings kept in the Name and the Description attribute.

HISTORY  New entity in IFC2.0.

IFC4 CHANGE  Description and Language attribute added; ReferencedLibrary attribute added (reversing previous ReferenceIntoLibrary inverse relationship).

Attribute definitions
#AttributeTypeCardinalityDescription G
4DescriptionIfcText? Additional description provided for the library reference.
IFC4 CHANGE  New attribute added at the end of the attribute list.
X
5LanguageIfcLanguageId? The language in which a library reference is expressed.
IFC4 CHANGE  New attribute added at the end of the attribute list.
X
6ReferencedLibraryIfcLibraryInformation? The library information that is being referenced. X
LibraryRefForObjectsIfcRelAssociatesLibrary
@RelatingLibrary
S[0:?]The library reference with which objects are associated.
IFC4 CHANGE  New inverse attribute.
X
Inherited definitions from supertypes
Entity inheritance IfcExternalReference
Attribute inheritance
#AttributeTypeCardinalityDescriptionG
IfcExternalReference
1LocationIfcURIReference? Location, where the external source (classification, document or library) can be accessed by electronic means. The electronic location is provided as an URI, and would normally be given as an URL location string.
IFC4 CHANGE  The data type has been changed from IfcLabel to IfcURIReference
.
X
2IdentificationIfcIdentifier? The Identification provides a unique identifier of the referenced item within the external source (classification, document or library). It may be provided as
  • a key, e.g. a classification notation, like NF2.3
  • a handle
  • a uuid or guid
It may be human readable (such as a key) or not (such as a handle or uuid) depending on the context of its usage (which has to be determined by local agreement).
IFC4 CHANGE Attribute renamed from ItemReference for consistency.
X
3NameIfcLabel? Optional name to further specify the reference. It can provide a human readable identifier (which does not necessarily need to have a counterpart in the internal structure of the document). X
ExternalReferenceForResourcesIfcExternalReferenceRelationship
@RelatingReference
S[0:?]Reference to all associations between this external reference and objects within the IfcResourceObjectSelect that are tagged by the external reference.
IFC4 CHANGE  New inverse attribute added with upward compatibility.
X
IfcLibraryReference
4DescriptionIfcText? Additional description provided for the library reference.
IFC4 CHANGE  New attribute added at the end of the attribute list.
X
5LanguageIfcLanguageId? The language in which a library reference is expressed.
IFC4 CHANGE  New attribute added at the end of the attribute list.
X
6ReferencedLibraryIfcLibraryInformation? The library information that is being referenced. X
LibraryRefForObjectsIfcRelAssociatesLibrary
@RelatingLibrary
S[0:?]The library reference with which objects are associated.
IFC4 CHANGE  New inverse attribute.
X
Formal representations
XML Specification
 <xs:element name="IfcLibraryReference" type="ifc:IfcLibraryReference" substitutionGroup="ifc:IfcExternalReference" nillable="true"/>
 <xs:complexType name="IfcLibraryReference">
  <xs:complexContent>
   <xs:extension base="ifc:IfcExternalReference">
    <xs:sequence>
     <xs:element name="ReferencedLibrary" type="ifc:IfcLibraryInformation" nillable="true" minOccurs="0"/>
    </xs:sequence>
    <xs:attribute name="Description" type="ifc:IfcText" use="optional"/>
    <xs:attribute name="Language" type="ifc:IfcLanguageId" use="optional"/>
   </xs:extension>
  </xs:complexContent>
 </xs:complexType>
EXPRESS Specification
ENTITY IfcLibraryReference
 SUBTYPE OF (IfcExternalReference);
  Description : OPTIONAL IfcText;
  Language : OPTIONAL IfcLanguageId;
  ReferencedLibrary : OPTIONAL IfcLibraryInformation;
 INVERSE
  LibraryRefForObjects : SET [0:?] OF IfcRelAssociatesLibrary FOR RelatingLibrary;
END_ENTITY;

Link to EXPRESS-G diagram EXPRESS-G diagram

References  References: IfcLibraryInformation IfcLibrarySelect

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