IFC (IFC4X3_ADD2) official IfcDocumentReference Semantic definition

An IfcDocumentReference is a reference to the location of a document. The reference is given by a system interpretable Location attribute (a URL string) where the document can be found, and an optional inherited internal reference Identification, which refers to a system interpretable position within the document. The optional inherited Name attribute is meant to have meaning for human readers. Optional document metadata can also be captured through reference to IfcDocumentInformation. Entity inheritance Attributes

# Attribute Type Description
IfcExternalReference (4)
1 Location OPTIONAL IfcURIReference

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.

2 Identification OPTIONAL IfcIdentifier

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).

3 Name OPTIONAL IfcLabel

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).

ExternalReferenceForResources SET [0:?] OF IfcExternalReferenceRelationship FOR RelatingReference

Reference to all associations between this external reference and objects within the IfcResourceObjectSelect that are tagged by the external reference.

Click to show 4 hidden inherited attributes Click to hide 4 inherited attributes
IfcDocumentReference (3)
4 Description OPTIONAL IfcText

Description of the document reference for informational purposes.

5 ReferencedDocument OPTIONAL IfcDocumentInformation

The document that is referenced.

DocumentRefForObjects SET [0:?] OF IfcRelAssociatesDocument FOR RelatingDocument

The document reference with which objects are associated.

Table Formal propositions

Name Description

A name should only be given, if no document information (including the document name) is attached

EXISTS(Name) XOR EXISTS(ReferencedDocument)
Table Examples Formal representation

ENTITY IfcDocumentReference
 SUBTYPE OF (IfcExternalReference);
	Description : OPTIONAL IfcText;
	ReferencedDocument : OPTIONAL IfcDocumentInformation;
	DocumentRefForObjects : SET [0:?] OF IfcRelAssociatesDocument FOR RelatingDocument;
	WR1 : EXISTS(Name) XOR EXISTS(ReferencedDocument);
END_ENTITY; References

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Is this page difficult to understand? Let us know! Changelog IFC4

  • attribute, Description
  • attribute, ReferencedDocument
  • where rule, WR1
  • where rule, WR1
  • inverse attribute ReferenceToDocument name, Changed from "ReferenceToDocument" to "DocumentRefForObjects"
  • inverse attribute ReferenceToDocument type, Changed from "SET OF [0:1] IfcDocumentInformation FOR DocumentReferences" to "SET OF [0:?] IfcRelAssociatesDocument FOR RelatingDocument"