|modifications||attributes EnumerationValues is_optional||Changed from False to True|
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 1 for an example of a enumerated property:
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.
Table 1 — Enumerated property with values, measure types and units
Table 2 — 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.
|HasExternalReferences||SET [0:?] OF IfcExternalReferenceRelationship FOR RelatedResourceObjects||Reference to an external reference, e.g. library, classification, or document information, that is associated to the property definition.|
> IFC4 CHANGE New inverse attribute.
|1||Name||IfcIdentifier||Name for this property. This label is the significant name string that defines the semantic meaning for the property.|
|2||Description||OPTIONAL IfcText||Informative text to explain the property.|
|PartOfPset||SET [0:?] OF IfcPropertySet FOR HasProperties||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.
|PropertyForDependance||SET [0:?] OF IfcPropertyDependencyRelationship FOR DependingProperty||The property on whose value that of another property depends.|
|PropertyDependsOn||SET [0:?] OF IfcPropertyDependencyRelationship FOR DependantProperty||The relating property on which the value of the property depends.|
|PartOfComplex||SET [0:?] OF IfcComplexProperty FOR HasProperties||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.
|HasConstraints||SET [0:?] OF IfcResourceConstraintRelationship FOR RelatedResourceObjects||User-defined constraints for the property.|
|HasApprovals||SET [0:?] OF IfcResourceApprovalRelationship FOR RelatedResourceObjects||User-defined approvals for the property.|
|3||EnumerationValues||OPTIONAL LIST [1:?] OF IfcValue||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.
|4||EnumerationReference||OPTIONAL IfcPropertyEnumeration||Enumeration from which a enumeration value has been selected. The referenced enumeration also establishes the unit of the enumeration value.|
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;