plz_no.ex

  defp refresh_graph(%{graph: g}) do
    g =
      if is_nil(g) do
        :digraph.new()
      else
        :digraph.delete(g)
        :digraph.new()
      end

    GraphDocument
    |> Repo.all()
    |> Enum.map(fn
      %{type: "vertex"} = v ->
        :digraph.add_vertex(g, v)

      %{type: "edge", from_id: f, to_id: t} = e ->
        from_vertex = g |> :digraph.vertices() |> Enum.find(fn v -> v.id === f end)
        to_vertex = g |> :digraph.vertices() |> Enum.find(fn v -> v.id === t end)

        :digraph.add_edge(g, from_vertex, to_vertex, e)
    end)

    {:noreply, %{graph: g}}
  end