bigapp_web.ex defmacro __using__ clause

using-view.ex

  @webdir "bigapp_web"

  @doc """
  When used, dispatch to the appropriate controller/view/etc.
  """
  defmacro __using__(:view) do
    view_path =
      __CALLER__.file
      |> String.split(@webdir)
      |> List.last
      |> Path.dirname
    templates = "lib/#{@webdir <> view_path}/templates"
    apply(__MODULE__, :view, [[root: templates,
                               namespace: __CALLER__.module,
                               pattern: "**/*"]])
  end