This section describes how to access relations on all models and model items in Creo application using the methods provided in Creo Object TOOLKIT C++.

In Creo Object TOOLKIT C++, the set of relations on any model or model item is represented by the pfcRelationOwner interface. Models, features, surfaces, and edges inherit from this interface, because each object can be assigned relations in Creo application.

Methods Introduced:

The method pfcRelationOwner::RegenerateRelations regenerates the relations assigned to the owner item. It also determines whether the specified relation set is valid.

The method pfcRelationOwner::DeleteRelations deletes all the relations assigned to the owner item.

The method pfcRelationOwner::GetRelations returns the list of initial relations assigned to the owner item as a sequence of strings.

The method pfcRelationOwner::SetRelations assigns the sequence of strings as the new relations to the owner item.

The method pfcRelationOwner::EvaluateExpression evaluates the given relations-based expression, and returns the resulting value in the form of the pfcParamValue object. Refer to the section The ParamValue Object in the section Dimensions and Parameters for more information on this object.

The method wfcWRelationOwner::EvaluateExpression has been deprecated. Use the method wfcWRelationOwner::EvaluateExpressionWithUnits instead.

Use the method wfcWRelationOwner::EvaluateExpressionWithUnits if you want the units of the relation to be considered while evaluating the expression. Specify the input argument Consider_units as true to consider the units. In this case, the result of the relation is returned along with its unit as wfcParamValueWithUnits object. Refer to the section The ParamValue Object in the section Dimensions and Parameters for more information on this object.

The method wfcWRelationOwner::UseUnits specifies if units must be considered while solving the specified relation. Use the method wfcWRelationOwner::UnitsUsed to check if units will be considered while solving the relation.