An IfcPropertyDependencyRelationship describes an identified dependency between the value of one property and that of another.
HISTORY New entity in IFC2x2
IFC4 CHANGE Made subtype of IfcResourceLevelRelationship (attribute order changed).
Whilst the IfcPropertyDependencyRelationship may be used to describe the dependency, and it may do so in terms of the expression of how the dependency operates, it is not possible through the current IFC model for the value of the related property to be actually derived from the value of the relating property. The determination of value according to the dependency is required to be performed by an application that can then use the Expression attribute to flag the form of the dependency.
|1||Name||OPTIONAL IfcLabel||A name used to identify or qualify the relationship.|
|2||Description||OPTIONAL IfcText||A description that may apply additional information about the relationship.|
|3||DependingProperty||IfcProperty||The property on which the relationship depends.|
|4||DependantProperty||IfcProperty||The dependant property.|
|5||Expression||OPTIONAL IfcText||Expression that further describes the nature of the dependency relation.|
ENTITY IfcPropertyDependencyRelationship SUBTYPE OF (IfcResourceLevelRelationship); DependingProperty : IfcProperty; DependantProperty : IfcProperty; Expression : OPTIONAL IfcText; WHERE NoSelfReference : DependingProperty :<>: DependantProperty; END_ENTITY;