Model Support Function Extension

nectar-web-product.ex

defmodule Nectar.ModelExtension do
  defmacro include_method([do: block]) do
    support_fn = Macro.escape(block)
    quote bind_quoted: [support_fn: support_fn] do
      Module.put_attribute(__MODULE__, :method_block, support_fn)
    end
  end
end

defmodule Nectar.ExtendProduct do
  Module.register_attribute(__MODULE__, :method_block, accumulate: true)
  import Nectar.ModelExtension

  include_method do: (def fn_from_outside, do: "support function")

  defmacro __before_compile__(_env) do
    @method_block
  end
end

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