Lately I've been working on some Revit railing enhancements. This is still work in progress, but some of the Dynamo nodes are already available online in my updated Zhukoven.com (rev.2017.8.17) package. Below you can see available railing Dynamo nodes (please note that currently all of these nodes support only one railing instance at a time):
Currently there's no direct link between the railing element and its hosted balusters through the Revit API. So in order to get the baluster profile data, we have to explode railing geometry and extract surfaces. Output values are diameters / widths of baluster elements.
This node calculates the number of railing balusters. See this post that explains the logic: Count railing balusters in Revit with Dynamo
Check if the railing element is hosted, and get this host element as an output (if applicable).
Get the list of lines that form the railing path.
Get top rail element (instance) from the input railing instance.
Input railing instance to get its type, primary handrail type, secondary handrail type, and top rail type. The node returns null values if selected railing type doesn't contain handrails.
Download an updated package (rev. 2017.08.17) from: Zhukoven.com