IfcPropertyEnumeratedValue

BACnet MVD

#### IfcPropertyEnumeratedValue

Natural language names

| Merkmal mit Aufzählungswert
| Property Enumerated Value
| Propriété à valeur issue d'un énumération

Change log

Item | SPF | XML | Change | Description
--- | --- | --- | --- | ---
IFC2x3 to IFC4
IfcPropertyEnumeratedValue |  |  |  |
EnumerationValues |  |  | MODIFIED | Instantiation changed to OPTIONAL.
IFC4 Addendum 1
IfcPropertyEnumeratedValue |  |  |  |
HasConstraints |  |  | ADDED |
HasApprovals |  |  | ADDED |

##### Semantic definitions at the entity

Entity definition

A property with an enumerated value, IfcPropertyEnumeratedValue, defines a property object which has a value assigned that is chosen from an enumeration. It defines a property - value combination for which the property Name, an optional Description, the optional EnumerationValues with measure type and optionally an Unit is given.

> NOTE Multiple choices from the property enumeration are supported.

The unit is handled by the Unit attribute, see Table 42 for an example of a enumerated property:

- If the Unit attribute is not given, then the unit is already implied by the type of IfcMeasureValue or IfcDerivedMeasureValue. The associated unit can be found at the IfcUnitAssignment globally defined at the project level (IfcProject.UnitsInContext).
- If the Unit attribute is given, then the unit assigned by the unit attribute overrides the globally assigned unit.

More precisely: The IfcPropertyEnumeratedValue defines a property, which value is selected from a defined list of enumerators. The enumerators are stored in a dynamic enumeration of values including the type information from IfcValue (see IfcPropertyEnumeration). This enables applications to use an enumeration value as a property within a property set (IfcPropertySet) including the allowed list of values.

> NOTE An IfcPropertyEnumeratedValue may be exchanged with no values assigned yet. In this case the EnumerationValues are set to NIL.

Name | Value (EnumerationValue) | Type (through IfcValue) | IfcPropertyEnumeration (Name)
--- | --- | --- | ---
BladeAction | Opposed | IfcLabel | DamperBladeActionEnum
BladeAction | Parallel | IfcLabel | DamperBladeActionEnum

Table 42 — Enumerated property with values, measure types and units

The IfcPropertyEnumeratedValue refers to an IfcPropertyEnumeration, see Table 43 for an example:

Name | EnumerationValues | Type (through IfcValue) | Unit
--- | --- | --- | ---
DamperBladeActionEnum | (Parallel, Opposed, Other, Unset) | IfcString | -

Table 43 — Property enumeration with enumerators

It is not mandatory to use an instance of IfcPropertyEnumeration to hold the applicable values for IfcPropertyEnumeratedValue, however this is the preferred way. A single instance of IfcPropertyEnumeration can be referenced by multiple instances of IfcPropertyEnumeratedValue.

> HISTORY New entity in IFC2.0.

> IFC2x CHANGE Entity has been renamed from IfcEnumeratedProperty

> IFC4 CHANGE Attribute EnumerationValues has been made OPTIONAL with upward compatibility for file based exchange.

Attribute definitions

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

3

EnumerationValues

IfcValue

? L[1:?]

Enumeration values, which shall be listed in the referenced IfcPropertyEnumeration, if such a reference is provided.

> IFC4 CHANGE The attribute has been made optional with upward compatibility for file based exchange.

X

X

4 | EnumerationReference | IfcPropertyEnumeration | ? | Enumeration from which a enumeration value has been selected. The referenced enumeration also establishes the unit of the enumeration value. | X | X

Formal Propositions

Rule | Description
--- | ---
WR21 | Each value within the list of EnumerationValues shall be a member of the list of EnumerationValues at the referenced IfcPropertyEnumeration (provided that both, the EnumerationValues and EnumerationReference, are asserted).

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

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

HasExternalReferences

IfcExternalReferenceRelationship
@RelatedResourceObjects

S[0:?]

Reference to an external reference, e.g. library, classification, or document information, that is associated to the property definition.

> IFC4 CHANGE New inverse attribute.

X

IfcProperty
1 | Name | IfcIdentifier |  | Name for this property. This label is the significant name string that defines the semantic meaning for the property. | X | X
2 | Description | IfcText | ? | Informative text to explain the property. | X | X

PartOfPset

IfcPropertySet
@HasProperties

S[0:?]

Reference to the IfcPropertySet by which the IfcProperty is referenced.

> IFC4 CHANGE New inverse attribute to navigate from IfcProperty to IfcPropertySet with upward compatibility for file based exchange.

X

| PropertyForDependance | IfcPropertyDependencyRelationship @DependingProperty | S[0:?] | The property on whose value that of another property depends. |  | X
| PropertyDependsOn | IfcPropertyDependencyRelationship @DependantProperty | S[0:?] | The relating property on which the value of the property depends. |  | X

PartOfComplex

IfcComplexProperty
@HasProperties

S[0:?]

Reference to the IfcComplexProperty in which the IfcProperty is contained.

> IFC4 CHANGE The cardinality has changed to 0..n to allow reuse of instances of IfcProperty in several IfcComplexProperty with upward compatibility for file based exchange.

X

| HasConstraints | IfcResourceConstraintRelationship @RelatedResourceObjects | ? S[0:?] | User-defined constraints for the property. |  | X
| HasApprovals | IfcResourceApprovalRelationship @RelatedResourceObjects | ? S[0:?] | User-defined approvals for the property. |  | X
IfcSimpleProperty
IfcPropertyEnumeratedValue

3

EnumerationValues

IfcValue

? L[1:?]

Enumeration values, which shall be listed in the referenced IfcPropertyEnumeration, if such a reference is provided.

> IFC4 CHANGE The attribute has been made optional with upward compatibility for file based exchange.

X

X

4 | EnumerationReference | IfcPropertyEnumeration | ? | Enumeration from which a enumeration value has been selected. The referenced enumeration also establishes the unit of the enumeration value. | X | X

##### Formal representations

XML Specification
`<xs:element name="IfcPropertyEnumeratedValue" type="ifc:IfcPropertyEnumeratedValue" substitutionGroup="ifc:IfcSimpleProperty" nillable="true"/>
<xs:complexType name="IfcPropertyEnumeratedValue">
<xs:complexContent>
<xs:extension base="ifc:IfcSimpleProperty">
<xs:sequence>
<xs:element name="EnumerationValues" nillable="true" minOccurs="0">
<xs:complexType>
<xs:group ref="ifc:IfcValue" maxOccurs="unbounded"/>
<xs:attribute ref="ifc:itemType" fixed="ifc:IfcValue"/>
<xs:attribute ref="ifc:cType" fixed="list"/>
<xs:attribute ref="ifc:arraySize" use="optional"/>
</xs:complexType>
</xs:element>
<xs:element name="EnumerationReference" type="ifc:IfcPropertyEnumeration" nillable="true" minOccurs="0"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcPropertyEnumeratedValue
SUBTYPE OF (IfcSimpleProperty);
EnumerationValues : OPTIONAL LIST [1:?] OF IfcValue;
EnumerationReference : OPTIONAL IfcPropertyEnumeration;
WHERE
WR21 : NOT(EXISTS(EnumerationReference))
OR NOT(EXISTS(EnumerationValues))
OR (SIZEOF(QUERY(temp <* EnumerationValues |
temp IN EnumerationReference.EnumerationValues))
= SIZEOF(EnumerationValues));
END_ENTITY;

EXPRESS-G diagram

`

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