Routing Preferences

Routing prefences are accessible through the RoutingPreferenceManager class. An instance of this class is available from a property of the MEPCurveType class. Currently, only PipeType and DuctType support routing preferences.

The RoutingPreferenceManager manages all rules for selecting segment types and sizes as well as fitting types based on user selection criteria. The RoutingPreferenceRule class manages one segment or fitting preference and instances of this class can be added to the RoutingPreferenceManager. Each routing preference rule is grouped according to what type of routing item in manages. The type is represented by the RoutingPreferenceRuleGroupType and includes these options:

Member name	Description
Undefined	Undefined group type (default initial value)
Segments	Segment types (e.g. pipe stocks)
Elbows	Elbow types
Junctions	Junction types (e.g. takeoff, tee, wye, tap)
Crosses	Cross types
Transitions	Transition types (Note that the multi-shape transitions may have their own groups)
Unions	Union types that connect two segments together
MechanicalJoints	Mechanical joint types that connect fitting to fitting, segment to fitting, or segment to segment
TransitionsRectangularToRound	Multi-shape transition from the rectangular profile to the round profile
TransitionsRectangularToOval	Multi-shape transition from the rectangular profile to the oval profile
TransitionsOvalToRound	Multi-shape transition from the oval profile to the round profile

Each routing preference rule can have one or more selection criteria, represented by the RoutingCriterionBase class, and the derived type PrimarySizeCriterion. PrimarySizeCriterion selects fittings and segments based on minimum and maximum size constraints.

The RoutingConditions class holds a collection of RoutingCondition instances. The RoutingCondition class represents routing information that is used as input when determining if a routing criterion, such as minimum or maximum diameter, is met. The RoutingPreferencesManager.GetMEPPartId() method gets a fitting or segment id based on a RoutingPreferenceRuleGroupType and RoutingConditions.

The following example gets all the pipe types in the document, gets the routing preference manager for each one, then gets the sizes for each segment based on the rules in the routing preference manager.

Code Region: Using Routing Preferences

private List<double> GetAvailablePipeSegmentSizesFromDocument(Document document)
{
    System.Collections.Generic.HashSet<double> sizes = new HashSet<double>();

    FilteredElementCollector collectorPipeType = new FilteredElementCollector(document);
    collectorPipeType.OfClass(typeof(PipeType));

    IEnumerable<PipeType> pipeTypes = collectorPipeType.ToElements().Cast<PipeType>();
    foreach (PipeType pipeType in pipeTypes)
    {
        RoutingPreferenceManager rpm = pipeType.RoutingPreferenceManager;

        int segmentCount = rpm.GetNumberOfRules(RoutingPreferenceRuleGroupType.Segments);
        for (int index = 0; index != segmentCount; ++index)
        {
            RoutingPreferenceRule segmentRule = rpm.GetRule(RoutingPreferenceRuleGroupType.Segments, index);
            Segment segment = document.GetElement(segmentRule.MEPPartId) as Segment;
            foreach (MEPSize size in segment.GetSizes())
            {
                sizes.Add(size.NominalDiameter);  //Use a hash-set to remove duplicate sizes among Segments and PipeTypes.
            }
        }
    }

    List<double> sizesSorted = sizes.ToList();
    sizesSorted.Sort();
    return sizesSorted;
}