IfcDocumentReference

BACnet MVD

#### IfcDocumentReference

Natural language names

| Bezug auf Dokument
| Document Reference
| Référence à un document

Change log

Item | SPF | XML | Change | Description
--- | --- | --- | --- | ---
IFC2x3 to IFC4
IfcDocumentReference |  |  |  |
Location |  |  | MODIFIED | Type changed from IfcLabel to IfcURIReference.
Identification |  | X | MODIFIED | Name changed from ItemReference to Identification.
Description |  |  | ADDED |
ReferencedDocument |  |  | ADDED |

##### Semantic definitions at the entity

Entity 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.

> HISTORY New entity in IFC2.0

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---

4

Description

IfcText

?

Description of the document reference for informational purposes.

> IFC4 CHANGE New attribute added at the end of the attribute list.

X

5 | ReferencedDocument | IfcDocumentInformation | ? | The document that is referenced. |  | X

DocumentRefForObjects

IfcRelAssociatesDocument
@RelatingDocument

S[0:?]

The document reference with which objects are associated.

> IFC4 CHANGE New inverse attribute.

X

Formal Propositions

Rule | Description
--- | ---
WR1 | A name should only be given, if no document information (including the document name) is attached

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
IfcExternalReference

1

Location

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
> .

X

X

2

Identification

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.

X

X

3 | Name | 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). | X | X

ExternalReferenceForResources

IfcExternalReferenceRelationship
@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

IfcDocumentReference

4

Description

IfcText

?

Description of the document reference for informational purposes.

> IFC4 CHANGE New attribute added at the end of the attribute list.

X

5 | ReferencedDocument | IfcDocumentInformation | ? | The document that is referenced. |  | X

DocumentRefForObjects

IfcRelAssociatesDocument
@RelatingDocument

S[0:?]

The document reference with which objects are associated.

> IFC4 CHANGE New inverse attribute.

X

##### Formal representations

XML Specification
`<xs:element name="IfcDocumentReference" type="ifc:IfcDocumentReference" substitutionGroup="ifc:IfcExternalReference" nillable="true"/>
<xs:complexType name="IfcDocumentReference">
<xs:complexContent>
<xs:extension base="ifc:IfcExternalReference">
<xs:sequence>
<xs:element name="ReferencedDocument" type="ifc:IfcDocumentInformation" nillable="true" minOccurs="0"/>
</xs:sequence>
<xs:attribute name="Description" type="ifc:IfcText" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`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;

EXPRESS-G diagram

`

References: IfcDocumentInformation IfcDocumentSelect

Link to this page