How to check if a family symbol is used in Routing Preferences

[dev]

Hi,

Is there a performant way of checking if a FamilySymbol is used in routing preferences?

I tried with GetDependentElements() method but it doesn't handle the routing preferences.

My use case is that I have to update the routing preferences of a duct type with new family symbols, but I also want to cleanup the old ones if they are not used anywhere (e.g. in the model itself and the routing preferences of other duct types).

We can consider this as another request for a Purge API.

[IbrahimNaeem]

1. collect all duct types. 

2. iterate through them in routing preferences per each routing preference group and store all family symbols. 

3. check if the current symbol is not a member of the above collection, then remove it. 

Hope this helps. 

[dev]

Thanks, this is the fallback brute force solution.