Dynamo-Set parameter of Type-Family Type


A family has type parameters, some of which are of Type: Family Type. Such parameters allow switching out nested family types: Autodesk Revit: Create a Nested Family with Interchangeable Components.

How does one generate a dictionary for the nested family types in order to set them by [Family Name] and [Type Name] from within Dynamo? My choice is to allow some error tolerance in the data in that the concatenation of the [Family Name] + [Type Name] is used as a “unique” identifier for the dictionary, the uniqueness of which is not necessarily true. Hence, care should be taken during production that this concatenation is indeed unique.  The dictionary passes a [Nested Family Type Reference] as a value.

The required nested family type can now be requested from the dictionary using a concatenation of the [Family Name] + [Type Name]. In the graph below, some of the input values were not found in the dictionary, and the setting of the parameter therefore excludes “null” values.

Within a python node: given the family name, select all the family’s types using a filter. Use the first family type and fetch all its parameters. Iterate through the parameters and then, if the parameter is op Type: Family Type, record the nested [Family Names], [Type Names] and [Nested Family Type References].



 import clr

 import sys


 from Autodesk.DesignScript.Geometry import *

 import math

 sys.path.append(r’C:\Program Files (x86)\IronPython 2.7\Lib’)


 import Revit



 clr.AddReference(“RevitServices”) # Import DocumentManager

 import RevitServices

 from RevitServices.Persistence import DocumentManager

 from RevitServices.Transactions import TransactionManager

 import traceback

 clr.AddReference(‘RevitAPI’) #import clr

 import Autodesk

 from Autodesk.Revit.DB import *

 from Autodesk.Revit.DB.Plumbing import *


 import System


 from DSCore import *

 doc = DocumentManager.Instance.CurrentDBDocument

 familyNameIn = IN[0]

 familyNames = []

 typeNames = []

 nestedFamilyTypeReferences = []

 bip = BuiltInParameter.SYMBOL_FAMILY_NAME_PARAM

 provider = ParameterValueProvider(ElementId(bip))

 evaluator = FilterStringEquals();

 rule = FilterStringRule(provider, evaluator, familyNameIn, True);

 filter = ElementParameterFilter(rule);

 familySymbols = FilteredElementCollector(doc).OfClass(FamilySymbol).WherePasses(filter).ToElements()

 family = familySymbols[0].Family

 for parameter in familySymbols[0].Parameters:

         if parameter.Definition.ParameterType == ParameterType.FamilyType:

             for nestedFamilyTypeReference in family.GetFamilyTypeParameterValues(parameter.Id):




 OUT = familyNames, typeNames, nestedFamilyTypeReferences 

The output from the Python node is used to create the Dictionary. While it is possible to output the values as row vectors for each relevant parameter, in this case the list is output as one-dimensional for simplicity in the application of the dictionary.