Model Support Function Extension

nectar-web-product.ex

defmodule Nectar.ExtendProduct do
  defmacro __before_compile__(_env) do
    quote do
      def fn_from_outside do
        "support function"
      end
    end
  end
end

defmodule Nectar.Product do
  ...
  # Add new support function here
  @before_compile Nectar.ExtendProduct
  ...
end