IfcTypeObject

BACnet MVD

#### IfcTypeObject

Natural language names

| Objekt (allgemein) - Typ
| Type Object
| Définition d'un type d'objet type

Change log

Item | SPF | XML | Change | Description
--- | --- | --- | --- | ---
IFC2x3 to IFC4
IfcTypeObject |  |  |  |
OwnerHistory |  |  | MODIFIED | Instantiation changed to OPTIONAL.
ApplicableOccurrence |  |  | MODIFIED | Type changed from IfcLabel to IfcIdentifier.

##### Semantic definitions at the entity

Entity 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 - occurrance modeling paradigm. The IfcTypeObject gets assigned to the individual object instances (the occurrences) via the IfcRelDefinesByType relationship.

> NOTE The terms 'Type' and 'Style' are often used interchangeably.

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.

> NOTE If a property having having the same name is used within the IfcPropertySet assigned to an IfcTypeObject (and subtypes) and to an occurrence of that type, then the occurrence property overrides the type property. See IfcRelDefinesByType for an explanatory figure.

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.

> HISTORY New entity in IFC2x

> IFC2x3 CHANGE The IfcTypeObject is now subtyped from the new supertype IfcObjectDefinition, and the attribute HasPropertySets has been changed from a LIST into a SET.

> IFC4 CHANGE The entity IfcTypeObject shall not be instantiated from IFC4 onwards. It will be changed into an ABSTRACT supertype in future releases of IFC. The inverse attribute Types has been renamed from ObjectTypeOf.

Attribute definitions

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---

5

ApplicableOccurrence

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 Refering to a furniture as applicable occurrence entity would be expressed as 'IfcFurnishingElement', refering to a brace as applicable entity would be expressed as 'IfcMember/BRACE', refering to a wall and wall standard case would be expressed as 'IfcWall, IfcWallStandardCase'.

X

6

HasPropertySets

IfcPropertySetDefinition

? S[1:?]

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.

X

X

| Types | IfcRelDefinesByType @RelatingType | S[0:1] | Reference to the relationship IfcRelDefinedByType and thus to those occurrence objects, which are defined by this type. |  | X

Formal Propositions

Rule | 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.
UniquePropertySetNames |

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | B
--- | --- | --- | --- | --- | ---
IfcRoot
1 | GlobalId | IfcGloballyUniqueId |  | Assignment of a globally unique identifier within the entire software world. | X | X

2

OwnerHistory

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.

X

X

3 | Name | 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. | X | X
4 | Description | IfcText | ? | Optional description, provided for exchanging informative comments. |  | X
IfcObjectDefinition
| HasAssignments | IfcRelAssigns @RelatedObjects | S[0:?] | 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. |  | X

Nests

IfcRelNests
@RelatedObjects

S[0:1]

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.

X

IsNestedBy

IfcRelNests
@RelatingObject

S[0:?]

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.

X

X

HasContext

IfcRelDeclares
@RelatedDefinitions

S[0:1]

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.

X

IsDecomposedBy

IfcRelAggregates
@RelatingObject

S[0:?]

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.

X

X

Decomposes

IfcRelAggregates
@RelatedObjects

S[0:1]

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.

X

X

| HasAssociations | IfcRelAssociates @RelatedObjects | S[0:?] | 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. | X | X
IfcTypeObject

5

ApplicableOccurrence

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 Refering to a furniture as applicable occurrence entity would be expressed as 'IfcFurnishingElement', refering to a brace as applicable entity would be expressed as 'IfcMember/BRACE', refering to a wall and wall standard case would be expressed as 'IfcWall, IfcWallStandardCase'.

X

6

HasPropertySets

IfcPropertySetDefinition

? S[1:?]

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.

X

X

| Types | IfcRelDefinesByType @RelatingType | S[0:1] | Reference to the relationship IfcRelDefinedByType and thus to those occurrence objects, which are defined by this type. |  | X

##### Definitions applying to Design Transfer View

Instance diagram

#####

Concept usage

Library Association

The Library Association concept applies to this entity.

mvdXML Specification
`<?xml version="1.0"?>
<ConceptRoot xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" uuid="54f6fcb9-fbe4-4587-8c2b-96d04ecb17e2" name="IfcTypeObject" status="sample" applicableRootEntity="IfcTypeObject">
<Concepts>
<Concept uuid="c14dae11-8132-48ae-ae57-ad0fbd6521b2" name="Library Association" status="sample" override="false">
<Template ref="3d761f09-23a2-4c01-8bc5-8762aa92bc23" />
</Concept>
</Concepts>
</ConceptRoot>
`
Concept inheritance

# | Concept | Template | Model View
--- | --- | --- | ---
IfcRoot
| Revision Control | Revision Control | Design Transfer View
IfcTypeObject
| Library Association | Library Association | Design Transfer View

##### Definitions applying to BACnet View

Concept inheritance

# | Concept | Template | Model View
--- | --- | --- | ---
IfcRoot
| Revision Control | Revision Control | Design Transfer View
IfcTypeObject
| Library Association | Library Association | Design Transfer View

##### Formal representations

XML Specification
`<xs:element name="IfcTypeObject" type="ifc:IfcTypeObject" substitutionGroup="ifc:IfcObjectDefinition" nillable="true"/>
<xs:complexType name="IfcTypeObject">
<xs:complexContent>
<xs:extension base="ifc:IfcObjectDefinition">
<xs:sequence>
<xs:element name="HasPropertySets" nillable="true" minOccurs="0">
<xs:complexType>
<xs:sequence>
<xs:element ref="ifc:IfcPropertySetDefinition" maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute ref="ifc:itemType" fixed="ifc:IfcPropertySetDefinition"/>
<xs:attribute ref="ifc:cType" fixed="set"/>
<xs:attribute ref="ifc:arraySize" use="optional"/>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attribute name="ApplicableOccurrence" type="ifc:IfcIdentifier" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`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;

EXPRESS-G diagram

`

References: IfcPropertySetDefinition IfcRelDefinesByType

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