IfcLibraryReference

Natural language names
deBibliothekseintrag
enLibrary Reference
frRéférence de bibliothèque
Change log
ItemSPFXMLChangeDescription
IFC2x3 to IFC4
    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 C
4DescriptionIfcText[0:1] Additional description provided for the library reference. X
5LanguageIfcLanguageId[0:1] The language in which a library reference is expressed. X
6ReferencedLibraryIfcLibraryInformation[0:1] The library information that is being referenced.X
LibraryRefForObjectsIfcRelAssociatesLibrary
@RelatingLibrary
S[0:?]The library reference with which objects are associated. X
Inherited definitions from supertypes
Entity inheritance IfcExternalReference
Attribute inheritance
#AttributeTypeCardinalityDescriptionC
IfcExternalReference
1LocationIfcURIReference[0:1] 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. X
2IdentificationIfcIdentifier[0:1] 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).
X
3NameIfcLabel[0:1] 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. X
IfcLibraryReference
4DescriptionIfcText[0:1] Additional description provided for the library reference. X
5LanguageIfcLanguageId[0:1] The language in which a library reference is expressed. X
6ReferencedLibraryIfcLibraryInformation[0:1] The library information that is being referenced.X
LibraryRefForObjectsIfcRelAssociatesLibrary
@RelatingLibrary
S[0:?]The library reference with which objects are associated. X
Examples
Formal representations
XSD 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

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