IFC 4.3.x development

8.6.3.5 IfcDocumentReference

Change log

IFC4

additions attributes Description
additions attributes ReferencedDocument
additions where_rules WR1
deletions where_rules WR1
modificationsinverses ReferenceToDocument definitionChanged from SET OF [0:1] IfcDocumentInformation FOR DocumentReferences to SET OF [0:?] IfcRelAssociatesDocument FOR RelatingDocument
modificationsinverses ReferenceToDocument name Changed from ReferenceToDocument to DocumentRefForObjects

8.6.3.5.1 Semantic definitions at the entity

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.

HISTORY  New entity in IFC2.0

8.6.3.5.1 Attributes

# Attribute Type Description
IfcExternalReference
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.

> IFC4 CHANGE  The data type has been changed from IfcLabel to IfcURIReference

> .
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).

> IFC4 CHANGE Attribute renamed from ItemReference for consistency.

>
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).
ExternalReferenceForResourcesSET [0:?] OF IfcExternalReferenceRelationship FOR RelatingReferenceReference 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.

>
IfcDocumentReference
4 Description OPTIONAL IfcText Description of the document reference for informational purposes.

> IFC4 CHANGE  New attribute added at the end of the attribute list.
5 ReferencedDocument OPTIONAL IfcDocumentInformation The document that is referenced.
DocumentRefForObjects SET [0:?] OF IfcRelAssociatesDocument FOR RelatingDocument The document reference with which objects are associated.

> IFC4 CHANGE  New inverse attribute.

8.6.3.5.2 Entity inheritance

dot_inheritance IfcDocumentReference IfcDocumentReference IfcExternalReference IfcExternalReference IfcDocumentReference->IfcExternalReference IfcExternalReference_children 5 more... IfcExternalReference_children->IfcExternalReference

8.6.3.5.3 Formal representations

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