IFC 4.3.x development

8.21.3.2 IfcOwnerHistory

Change log

IFC4

additions where_rules CorrectChangeAction
modificationsattributes ChangeAction is_optionalChanged from False to True

8.21.3.2.1 Semantic definitions at the entity

IfcOwnerHistory defines all history and identification related information. In order to provide fast access it is directly attached to all independent objects, relationships and properties.

IfcOwnerHistory is used to identify the creating and owning application and user for the associated object, as well as capture the last modifying application and user.

HISTORY  New entity in IFC1.0.

IFC4 CHANGE  ChangeAction is now optional and a related WHERE rule enforces conditions when it is asserted.

Informal Propositions:

  1. If LastModifiedDate is defined but ChangeAction is not asserted, then the state of ChangeAction is assumed to be UNDEFINED.
  2. If both LastModifiedDate and ChangeAction are asserted, then the state of ChangeAction applies to the value asserted in LastModifiedDate.

8.21.3.2.1 Attributes

#Attribute Type Description
IfcOwnerHistory
1OwningUser IfcPersonAndOrganization Direct reference to the end user who currently "owns" this object. Note that IFC includes the concept of ownership transfer from one user to another and therefore distinguishes between the Owning User and Creating User.
2OwningApplication IfcApplication Direct reference to the application which currently "owns" this object on behalf of the owning user of the application. Note that IFC includes the concept of ownership transfer from one application to another and therefore distinguishes between the Owning Application and Creating Application.
3State OPTIONAL IfcStateEnum Enumeration that defines the current access state of the object.
4ChangeAction OPTIONAL IfcChangeActionEnum Enumeration that defines the actions associated with changes made to the object.
5LastModifiedDate OPTIONAL IfcTimeStamp Date and Time expressed in UTC (Universal Time Coordinated, formerly Greenwich Mean Time or GMT) at which the last modification was made by LastModifyingUser and LastModifyingApplication.
6LastModifyingUser OPTIONAL IfcPersonAndOrganizationUser who carried out the last modification using LastModifyingApplication.
7LastModifyingApplicationOPTIONAL IfcApplication Application used to make the last modification.
8CreationDate IfcTimeStamp The date and time expressed in UTC (Universal Time Coordinated, formerly Greenwich Mean Time or GMT) when first created by the original OwningApplication. Once defined this value remains unchanged through the lifetime of the entity.

8.21.3.2.2 Entity inheritance

dot_inheritance IfcOwnerHistory IfcOwnerHistory

8.21.3.2.3 Formal representations

ENTITY IfcOwnerHistory;
	OwningUser : IfcPersonAndOrganization;
	OwningApplication : IfcApplication;
	State : OPTIONAL IfcStateEnum;
	ChangeAction : OPTIONAL IfcChangeActionEnum;
	LastModifiedDate : OPTIONAL IfcTimeStamp;
	LastModifyingUser : OPTIONAL IfcPersonAndOrganization;
	LastModifyingApplication : OPTIONAL IfcApplication;
	CreationDate : IfcTimeStamp;
 WHERE
	CorrectChangeAction : (EXISTS(LastModifiedDate)) OR
(NOT(EXISTS(LastModifiedDate)) AND NOT(EXISTS(ChangeAction))) OR
(NOT(EXISTS(LastModifiedDate)) AND EXISTS(ChangeAction) AND ((ChangeAction = IfcChangeActionEnum.NOTDEFINED) OR (ChangeAction = IfcChangeActionEnum.NOCHANGE)));
END_ENTITY;