IfcProxy

IfcProxy

Definition from IAI: The IfcProxy is intended to be a kind of a container for wrapping objects which are defined by associated properties, which may or may not have a geometric representation and placement in space. A proxy may have a semantic meaning, defined by the Name attribute, and property definitions, attached through the property assignment relationship, which definition may be outside of the definitions given by the current release of IFC.

The ProxyType may give an indication to which high level semantic breakdown of object the semantic definition of the proxy relates to. the Tag attribute may be used to assign a human or system interpretable identifier (such as a serial number or bar code).

NOTE 1 Given that only a limited number of semantic constructs can be formally defined within IFC (and it will never be possible to define all), there has to be a mechanism for capturing those constructs that are not (yet) defined by IFC.

NOTE 2 Product proxies are a mechanism that allows to exchange data that is part of the project but not necessarily part of the IFC model. Those proxies may have geometric representations assigned.

HISTORY New entity in IFC Release 1.5.

EXPRESS specification:

ENTITY IfcProxy

SUBTYPE OF (

IfcProduct);

ProxyType

IfcObjectTypeEnum;

Tag

OPTIONAL IfcLabel;

WHERE

WR1

EXISTS(SELF\IfcRoot.Name);

END_ENTITY;

Attribute definitions:

ProxyType	:	High level (and only) semantic meaning attached to the IfcProxy, defining the basic construct type behind the Proxy, e.g. Product or Process.
Tag	:	The tag (or label) identifier at the particular instance of a product, e.g. the serial number, or the position number. It is the identifier at the occurrance level.

Formal Propositions:

WR1

The Name attribute has to be provided for a proxy.

Inheritance graph

ENTITY IfcProxy;

ENTITY IfcRoot;

GlobalId

IfcGloballyUniqueId;

OwnerHistory

IfcOwnerHistory;

Name

OPTIONAL IfcLabel;

Description

OPTIONAL IfcText;

ENTITY IfcObject;

ObjectType

OPTIONAL IfcLabel;

INVERSE

IsDefinedBy

SET OF IfcRelDefines FOR RelatedObjects;

HasAssociations

SET OF IfcRelAssociates FOR RelatedObjects;

HasAssignments

SET OF IfcRelAssigns FOR RelatedObjects;

Decomposes

SET [0:1] OF IfcRelDecomposes FOR RelatedObjects;

IsDecomposedBy

SET OF IfcRelDecomposes FOR RelatingObject;

ENTITY IfcProduct;

ObjectPlacement

OPTIONAL IfcObjectPlacement;

Representation

OPTIONAL IfcProductRepresentation;

INVERSE

ReferencedBy

SET OF IfcRelAssignsToProduct FOR RelatingProduct;

ENTITY IfcProxy;

ProxyType

IfcObjectTypeEnum;

Tag

OPTIONAL IfcLabel;

END_ENTITY;