5.1.3.46 IfcTypeObject

5.1.3.46.1 Semantic definition

The object type defines the specific information about a type, being common to all occurrences of this type. It refers to the specific level of the well recognized generic - specific - occurrence modeling paradigm. The IfcTypeObject gets assigned to the individual object instances (the occurrences) via the IfcRelDefinesByType relationship.

The object type is represented by a set of property set definitions. The attached property sets describe the available alpha-numeric information about the object type. and are used to define all common properties that apply to all object occurrences of that type.

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 pointing to IfcRelAssociatesLibrary.

5.1.3.46.2 Entity inheritance

- IfcRoot

5.1.3.46.3 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, NOTE only the last modification in stored - either as addition, deletion or modification. IFC4-CHANGE The attribute has been changed to be OPTIONAL.
3	Name	OPTIONAL IfcLabel	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	Optional description, provided for exchanging informative comments.
IfcObjectDefinition (7)
	HasAssignments	SET [0:?] OF IfcRelAssigns FOR RelatedObjects	Reference to the relationship objects, that assign (by an association relationship) other subtypes of IfcObject to this object instance. Examples are the association to products, processes, controls, resources or groups.
	Nests	SET [0:1] OF IfcRelNests FOR RelatedObjects	References to the decomposition relationship being a nesting. It determines that this object definition is a part within an ordered whole/part decomposition relationship. An object occurrence or type can only be part of a single decomposition (to allow hierarchical strutures only). IFC4-CHANGE The inverse attribute datatype has been added and separated from Decomposes defined at IfcObjectDefinition.
	IsNestedBy	SET [0:?] OF IfcRelNests FOR RelatingObject	References to the decomposition relationship being a nesting. It determines that this object definition is the whole within an ordered whole/part decomposition relationship. An object or object type can be nested by several other objects (occurrences or types). IFC4-CHANGE The inverse attribute datatype has been added and separated from IsDecomposedBy defined at IfcObjectDefinition.
	HasContext	SET [0:1] OF IfcRelDeclares FOR RelatedDefinitions	References to the context providing context information such as project unit or representation context. It should only be asserted for the uppermost non-spatial object. IFC4-CHANGE The inverse attribute datatype has been added.
	IsDecomposedBy	SET [0:?] OF IfcRelAggregates FOR RelatingObject	References to the decomposition relationship being an aggregation. It determines that this object definition is whole within an unordered whole/part decomposition relationship. An object definitions can be aggregated by several other objects (occurrences or parts). IFC4-CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
	Decomposes	SET [0:1] OF IfcRelAggregates FOR RelatedObjects	References to the decomposition relationship being an aggregation. It determines that this object definition is a part within an unordered whole/part decomposition relationship. An object definitions can only be part of a single decomposition (to allow hierarchical strutures only). IFC4-CHANGE The inverse attribute datatype has been changed from the supertype IfcRelDecomposes to subtype IfcRelAggregates.
	HasAssociations	SET [0:?] OF IfcRelAssociates FOR RelatedObjects	Reference to the relationship objects, that associates external references or other resource definitions to the object.. Examples are the association to library, documentation or classification.
Click to show 11 hidden inherited attributes Click to hide 11 inherited attributes
IfcTypeObject (3)
5	ApplicableOccurrence	OPTIONAL IfcIdentifier	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. The following conventions are used: * The IFC entity name of the applicable occurrence using the IFC naming convention, CamelCase with IFC prefix * It can be optionally followed by the predefined type after the separator "/" (forward slash), using uppercase * If one type object is applicable to many occurrence objects, then those occurrence object names should be separate by comma "," forming a comma separated string. EXAMPLE Referring to a furniture as applicable occurrence entity would be expressed as 'IfcFurnishingElement', referring to a brace as applicable entity would be expressed as 'IfcMember/BRACE'.
6	HasPropertySets	OPTIONAL SET [1:?] OF IfcPropertySetDefinition	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. IFC2x3-CHANGE The attribute aggregate type has been changed from LIST to SET.
	Types	SET [0:1] OF IfcRelDefinesByType FOR RelatingType	Reference to the relationship IfcRelDefinedByType and thus to those occurrence objects, which are defined by this type.

Table 5.1.3.46.A

5.1.3.46.4 Formal propositions

Name	Description
NameRequired	A Name attribute has to be provided. The name can be declared within the IFC specification as part of the property set agreements.
`EXISTS(SELF\IfcRoot.Name)`
UniquePropertySetNames	No description available.
`(NOT(EXISTS(HasPropertySets))) OR IfcUniquePropertySetNames(HasPropertySets)`

Table 5.1.3.46.B

5.1.3.46.5 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 provide for a name and a description about the concept.
IfcObjectDefinition (9)
Aggregation	General	No description available.
Approval Association	General	No description available.
Classification Association	General	Any object occurrence or object type can have a reference to a specific classification reference, i.e. to a particular facet within a classification system.
Constraint Association	General	No description available.
Document Association	General	No description available.
Library Association	General	No description available.
Material Association	General	No description available.
Material Single	General	No description available.
Nesting	General	No description available.
Click to show 11 hidden inherited concepts Click to hide 11 inherited concepts
IfcTypeObject (1)
Property Sets for Types	General	No description available.

Table 5.1.3.46.C

5.1.3.46.6 Formal representation

ENTITY IfcTypeObject
 SUPERTYPE OF (ONEOF
	(IfcTypeProcess
	,IfcTypeProduct
	,IfcTypeResource))
 SUBTYPE OF (IfcObjectDefinition);
	ApplicableOccurrence : OPTIONAL IfcIdentifier;
	HasPropertySets : OPTIONAL SET [1:?] OF IfcPropertySetDefinition;
 INVERSE
	Types : SET [0:1] OF IfcRelDefinesByType FOR RelatingType;
 WHERE
	NameRequired : EXISTS(SELF\IfcRoot.Name);
	UniquePropertySetNames : (NOT(EXISTS(HasPropertySets))) OR IfcUniquePropertySetNames(HasPropertySets);
END_ENTITY;