AE
Ash Elixir•2y ago
barnabasj

have the generator return values from a list (unique)

Hi, I would like to use the generator functionality to create resources and I have a attribute with specific codes. I'm looking for a way to pass a generator that returns values from a list but does not return the same value twice in order for the unique constraint to work correctly.
1 Reply
barnabasj
barnabasjOP•2y ago
I found a way to encapsulate it into a 0 arity function that I can pass to StreamData.repeatedly 
 def codes do
    {:ok, pid} = Agent.start(fn -> @codes end)

    {pid,
     fn ->
       case Agent.get(pid, & &1) do
         [] ->
           nil

         [hotel_code | hotel_codes] ->
           Agent.update(pid, fn _ -> hotel_codes end)
           hotel_code
       end
     end}
  end

  {agent, codes} = codes()

   Api.bulk_create!(
      Enum.take(
        Ash.Generator.action_input(Hotel, :new, Map.merge(generators(), %{codes: StreamData.repeatedly(codes)),
        2
      ),
      Hotel,
      :new,
      actor: @actor,
      stop_on_error?: true
    )

  Agent.stop(agent) 
 def codes do
    {:ok, pid} = Agent.start(fn -> @codes end)

    {pid,
     fn ->
       case Agent.get(pid, & &1) do
         [] ->
           nil

         [hotel_code | hotel_codes] ->
           Agent.update(pid, fn _ -> hotel_codes end)
           hotel_code
       end
     end}
  end

  {agent, codes} = codes()

   Api.bulk_create!(
      Enum.take(
        Ash.Generator.action_input(Hotel, :new, Map.merge(generators(), %{codes: StreamData.repeatedly(codes)),
        2
      ),
      Hotel,
      :new,
      actor: @actor,
      stop_on_error?: true
    )

  Agent.stop(agent)

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