How do I filter an action by multiple arguments but allow one or more of the arguments to be nil, and in those cases, drop that filter clause?

In other words, with what I’ve written, all the arguments are needed or no results are returned.

localhost:4000/api/flows?inlclude=project&include=phase&include=flow_phase&owned_by=guild&status=active&phase_status=current

returns results, but

localhost:4000/api/flows?inlclude=project&include=phase&include=flow_phase&owned_by=guild&status=active

returns nothing. My desire is that it would have returned MORE results.

I’m relatively new to both Ash and Elixir, so please forgive me if the answer should be obvious.

Here’s my action:

actions do
    defaults [:create]

    read :read do
      primary? true
      prepare(build(load: [:project]))

      argument :status, :atom do
        allow_nil? true
      end

      argument :owned_by, :atom do
        allow_nil? true
      end

      argument :phase_status, :atom do
        allow_nil? true
      end

      filter expr(
               status == ^arg(:status) and flow_phase.status == (^arg(:phase_status)) and
                 flow_phase.phase.owned_by == ^arg(:owned_by)
             )
    end
  end