Interesting… I’d suggest also checking elements in the model to ensure that the id doesn’t exist already as well. Alternatively you could somehow tie the algorithm to the actual unique Id in Revit itself to get a simpler potentially unique Id as well.
I’d probably add the existing ID list before the LIST.UniqueItems node to do that.
At that point I guess I would wonder if we just use Unique Id’s then?
I have a project that hasn’t been started yet, but we were planning to something similar to this. We wanted a way to relate detail items in a drafting view to actual model elements. When the items get relocated, the associated object could be updated too. The idea was to add a parameter to both objects that would hold the data and tie them together with this ID. Is there another way to accomplish relating things like this together with the existing IDs or data in the model?
Filter elements by common parameter value and then move them appropriately.