5.1.3.42 IfcRelationship
ABSTRACT This definition may not be instantiated
5.1.3.42.1 Semantic definition
IfcRelationship is the abstract generalization of all objectified relationships in IFC. Objectified relationships are the preferred way to handle relationships among objects. This allows keeping relationship-specific properties directly at the relationship and opens the possibility to later handle relationship-specific behaviour.
There are two different types of relationships, 1-to-1 relationships and 1-to-many relationships, used within the subtypes of IfcRelationship. The following convention applies to all subtypes:
- The two sides of the objectified relationship are named Relating+
and Related+ - In case of the 1-to-many relationship, the related side of the relationship shall be an aggregate, representing a set with cardinality 1..n
5.1.3.42.2 Entity inheritance
5.1.3.42.3 Attributes
| # | Attribute | Type | Description |
|---|---|---|---|
| IfcRoot (4) | |||
| 1 | GlobalId | IfcGloballyUniqueId |
Assignment of a globally unique identifier within the entire software world. |
| 2 | OwnerHistory | OPTIONAL IfcOwnerHistory |
Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object. |
| 3 | Name | OPTIONAL IfcLabel |
An optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule. |
| 4 | Description | OPTIONAL IfcText |
An optional description, provided to exchange informative comments. |
5.1.3.42.4 Concept usage
| Concept | Usage | Description | |
|---|---|---|---|
| IfcRoot (2) | |||
| Revision Control | General |
Ownership, history, and merge state is captured using IfcOwnerHistory. |
|
| Software Identity | General |
IfcRoot assigns the globally unique ID. In addition, it may also provide a name and description for the concept. |
|
| Click to show 2 hidden inherited concepts Click to hide 2 inherited concepts | |||
5.1.3.42.5 Formal representation
ENTITY IfcRelationship
ABSTRACT SUPERTYPE OF (ONEOF
(IfcRelAssigns
,IfcRelAssociates
,IfcRelConnects
,IfcRelDeclares
,IfcRelDecomposes
,IfcRelDefines))
SUBTYPE OF (IfcRoot);
END_ENTITY;
