IfcRelAssignsToGroup

Definition from IAI: This objectified relationship (IfcRelAssignsToGroup) handles the assignment of objects (subtypes of IfcObject) to a group (subtypes of IfcGroup).

The relationship handles the assignment of group members to the group object. It allows for grouping arbitrary objects within a group, including other groups. The grouping relationship can be applied in a recursive manner. The resulting group is of type IfcGroup. The Purpose attribute defined at the supertype IfcReleationship, may assign a descriptor, that defines the purpose of the group.

The inherited attribute RelatedObjects gives the references to the objects, which are the elements within the group. The RelatingGroup is the group, that comprises all elements.

Informal proposition:

1. The group assignment relationship shall be a-cyclic, i.e. a group should not participate in its own grouping relationship.

> HISTORY New entity in IFC Release 1.0. Has been renamed from IfcRelGroups in IFC Release 2x..

EXPRESS specification:

ENTITY IfcRelAssignsToGroup
SUBTYPE OF ( | IfcRelAssigns);
RelatingGroup | : | IfcGroup;
WHERE
WR1 | : | SIZEOF(QUERY(Temp <* SELF\IfcRelAssigns.RelatedObjects | RelatingGroup :=: Temp)) = 0;
END_ENTITY;

Attribute definitions:

RelatingGroup | : | Reference to group that finally contains all assigned group members.

Formal Propositions:

WR1 | : | The instance to with the relation points shall not be contained in the List of RelatedObjects.

Inheritance graph

ENTITY IfcRelAssignsToGroup;
ENTITY IfcRoot;
GlobalId | : | IfcGloballyUniqueId;
OwnerHistory | : | IfcOwnerHistory;
Name | : | OPTIONAL IfcLabel;
Description | : | OPTIONAL IfcText;
ENTITY IfcRelationship;
ENTITY IfcRelAssigns;
RelatedObjects | : | SET [1:?] OF IfcObjectDefinition;
RelatedObjectsType | : | OPTIONAL IfcObjectTypeEnum;
ENTITY IfcRelAssignsToGroup;
RelatingGroup | : | IfcGroup;
END_ENTITY;