mjml.ex

mjml.ex

defmodule Readable.Emails.MJML do
  @external_resource __DIR__

  def mjml_template(path) do
    template = path |> Path.expand(__DIR__) |> File.read!()

    {:ok, html} =
      ~r|<mj-include\s+path="([^"]*)"\s+/>|
      |> Regex.scan(template)
      |> Enum.map(fn [match, path] ->
        {match, path |> Path.expand(__DIR__) |> File.read!()}
      end)
      |> Enum.reduce(template, fn {match, replacement}, template ->
        String.replace(template, match, replacement)
      end)
      |> Mjml.to_html()

    html
    |> String.replace("{{", "<%=")
    |> String.replace("}}", "%>")
  end

  defmacro __using__(_) do
    for path <- Path.wildcard("#{__DIR__}/*.mjml.eex") do
      quote do
        @external_resource unquote(path)
        def mjml_template(unquote(Path.basename(path, ".mjml.eex")), bindings) do
          template = unquote(mjml_template(path))
          EEx.eval_string(template, bindings)
        end
      end
    end
  end
end