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IfcTypeObject

Definition from buildingSMART: The object type (IfcTypeObject) defines the specific information about a type. It refers to the specific level of the well recognized generic - specific - occurrence modeling paradigm.

The object style is represented by a list of property set definitions, where the order in the list implies a decreasing generality. The list of property sets describes the available specific information about the object type. Thereby the object type is used to define the common properties of a certain type (or style) of an object that may be applied to multiple instances of the same type. The IfcTypeObject gets assigned to the individual object instances (the occurrences) via the IfcRelDefinesByType relationship.

Object types may be exchanged without being already assigned to objects. An object type may have an indication of the library (or catalogue) from which its definition originates. This association is handled by the inherited HasAssociations relationship.

HISTORY: New entity in IFC Release 2x.

EXPRESS specification:

ENTITY IfcTypeObject
SUPERTYPE OF (IfcTypeProduct)
SUBTYPE OF ( IfcObjectDefinition);
ApplicableOccurrence  :  OPTIONAL IfcLabel;
HasPropertySets  :  OPTIONAL SET [1:?] OF IfcPropertySetDefinition;
INVERSE
ObjectTypeOf  :  SET [0:1] OF IfcRelDefinesByType FOR RelatingType;
WHERE
WR1  :  EXISTS(SELF\IfcRoot.Name);
END_ENTITY;

Attribute definitions:

ApplicableOccurrence  :  The attribute optionally defines the data type of the occurrence object, to which the assigned type object can relate. If not present, no instruction is given to which occurrence object the type object is applicable.
HasPropertySets  :  Set list of unique property sets, that are associated with the object type and are common to all object occurrences referring to this object type.
IFC2x Edition 3 CHANGE  The attribute aggregate type has been changed from LIST to SET.
ObjectTypeOf  :  Reference to the relationship IfcRelDefinedByType and thus to those occurrence objects, which are defined by this type.

Formal Propositions:

WR1  :  A Name attribute has to be provided. The name can be declared within the IFC specification as part of the property set agreements.

Inheritance graph

ENTITY IfcTypeObject;
ENTITY IfcRoot;
GlobalId  :  IfcGloballyUniqueId;
OwnerHistory  :  IfcOwnerHistory;
Name  :  OPTIONAL IfcLabel;
Description  :  OPTIONAL IfcText;
ENTITY IfcObjectDefinition;
INVERSE
HasAssignments  :  SET OF IfcRelAssigns FOR RelatedObjects;
IsDecomposedBy  :  SET OF IfcRelDecomposes FOR RelatingObject;
Decomposes  :  SET [0:1] OF IfcRelDecomposes FOR RelatedObjects;
HasAssociations  :  SET OF IfcRelAssociates FOR RelatedObjects;
ENTITY IfcTypeObject;
ApplicableOccurrence  :  OPTIONAL IfcLabel;
HasPropertySets  :  OPTIONAL SET [1:?] OF IfcPropertySetDefinition;
INVERSE
ObjectTypeOf  :  SET [0:1] OF IfcRelDefinesByType FOR RelatingType;
END_ENTITY;