IfcPropertyEnumeration

Definition from IAI: A collection of simple or measure values that define a prescribed set of alternatives from which 'enumeration values' are selected. This enables inclusion of enumeration values in property sets. IfcPropertyEnumeration provides a name for the enumeration as well as a list of unique (numeric or descriptive) values (that may have a measure type assigned). The entity defines the list of potential enumerators to be exchanged together (or separately) with properties of type IfcPropertyEnumeratedValue that selects their actual property values from this enumeration.

The unit is handled by the Unit attribute:

If the Unit attribute is not given, than 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, the unit assigned by the unit attribute overrides the globally assigned unit.

Name	EnumerationValues	Type (through IfcValue)	Unit
PEnum_DamperBladeAction	Parallel	IfcString	-
	Opposed	IfcString
	Other	IfcString
	Unset	IfcString

HISTORY: New Entity in IFC Release 2.0, capabilities enhanced in IFC Release 2x. Entity has been renamed from IfcEnumeration in IFC Release 2x.

EXPRESS specification:

ENTITY IfcPropertyEnumeration;

Name

IfcLabel;

EnumerationValues

LIST [1:?] OF UNIQUE IfcValue;

Unit

OPTIONAL IfcUnit;

UNIQUE

UR1

Name;

WHERE

WR01

SIZEOF(QUERY(temp <* SELF.EnumerationValues | NOT(TYPEOF(SELF.EnumerationValues[1]) = TYPEOF(temp)) )) = 0;

END_ENTITY;

Attribute definitions:

Name	:	Name of this enumeration.
EnumerationValues	:	List of values that form the enumeration.
Unit	:	Unit for the enumerator values, if not given, the default value for the measure type (given by the TYPE of nominal value) is used as defined by the global unit assignment at IfcProject.

Formal Propositions: