IFC 4.3.0.1 (IFC4X3_TC1)

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

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,

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).

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).

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.

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).

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).

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.

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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.

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.

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.

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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;

5.1.3.46.7 References

5.1.3.46.8 Changelog

5.1.3.46.8.1 IFC4

  • where rule, NameRequired
  • where rule, UniquePropertySetNames
  • where rule, WR1
  • attribute ApplicableOccurrence type, Changed from "IfcLabel" to "IfcIdentifier"
  • inverse attribute ObjectTypeOf name, Changed from "ObjectTypeOf" to "Types"