Interpolation Behaviour Message Format (#294) (#295)

lib/gettext/compiler.ex

@@ -28,6 +28,8 @@ defmodule Gettext.Compiler do
 
     default_domain = opts[:default_domain] || @default_domain
 
+    interpolation = opts[:interpolation] || Gettext.Interpolation.Default
+
     quote do
       @behaviour Gettext.Backend
 
@@ -38,6 +40,7 @@ defmodule Gettext.Compiler do
       def __gettext__(:known_locales), do: unquote(known_locales)
       def __gettext__(:default_locale), do: unquote(default_locale)
       def __gettext__(:default_domain), do: unquote(default_domain)
+      def __gettext__(:interpolation), do: unquote(interpolation)
 
       # The manifest lives in the root of the priv
       # directory that contains .po/.pot files.

lib/gettext/extractor.ex

@@ -56,8 +56,17 @@ defmodule Gettext.Extractor do
   """
   @spec extract(Macro.Env.t(), module, binary, binary, binary | {binary, binary}, [binary]) :: :ok
   def extract(%Macro.Env{} = caller, backend, domain, msgctxt, id, extracted_comments) do
+    format_flag = backend.__gettext__(:interpolation).message_format()
+
     translation =
-      create_translation_struct(id, msgctxt, caller.file, caller.line, extracted_comments)
+      create_translation_struct(
+        id,
+        msgctxt,
+        caller.file,
+        caller.line,
+        extracted_comments,
+        format_flag
+      )
 
     ExtractorAgent.add_translation(backend, domain, translation)
   end
@@ -146,26 +155,31 @@ defmodule Gettext.Extractor do
     update_in(translation.references, &Enum.sort/1)
   end
 
-  defp create_translation_struct({msgid, msgid_plural}, msgctxt, file, line, extracted_comments) do
+  defp create_translation_struct(
+         {msgid, msgid_plural},
+         msgctxt,
+         file,
+         line,
+         extracted_comments,
+         format_flag
+       ) do
     %PluralTranslation{
       msgid: [msgid],
       msgctxt: if(msgctxt != nil, do: [msgctxt], else: nil),
       msgid_plural: [msgid_plural],
       msgstr: %{0 => [""], 1 => [""]},
-      # TODO: Get Format Flag dynamically when extracting
-      flags: MapSet.new([@extracted_translations_flag, "elixir-format"]),
+      flags: MapSet.new([@extracted_translations_flag, format_flag]),
       references: [{Path.relative_to_cwd(file), line}],
       extracted_comments: extracted_comments
     }
   end
 
-  defp create_translation_struct(msgid, msgctxt, file, line, extracted_comments) do
+  defp create_translation_struct(msgid, msgctxt, file, line, extracted_comments, format_flag) do
     %Translation{
       msgid: [msgid],
       msgctxt: if(msgctxt != nil, do: [msgctxt], else: nil),
       msgstr: [""],
-      # TODO: Get Format Flag dynamically when extracting
-      flags: MapSet.new([@extracted_translations_flag, "elixir-format"]),
+      flags: MapSet.new([@extracted_translations_flag, format_flag]),
       references: [{Path.relative_to_cwd(file), line}],
       extracted_comments: extracted_comments
     }

lib/gettext/interpolation.ex

@@ -14,4 +14,10 @@ defmodule Gettext.Interpolation do
                    message :: String.t(),
                    bindings :: map()
                  ) :: Macro.t()
+
+  @doc """
+  Defines the gettext message format
+  https://www.gnu.org/software/gettext/manual/html_node/PO-Files.html#index-msgstr
+  """
+  @callback message_format :: String.t()
 end

lib/gettext/interpolation/default.ex

@@ -212,4 +212,7 @@ defmodule Gettext.Interpolation.Default do
 
     {:<<>>, [], parts}
   end
+
+  @impl Gettext.Interpolation
+  def message_format, do: "elixir-format"
 end

lib/gettext/po/translations.ex

@@ -14,7 +14,7 @@ defmodule Gettext.PO.Translations do
   @doc """
   Tells whether a translation was manually entered or generated by Gettext.
 
-  As of now, a translation is considered autogenerated if it has the "elixir-format" flag.
+  As of now, a translation is considered autogenerated if it has the "ex-autogen" flag.
 
   ## Examples
 

test/gettext_test.exs

@@ -49,6 +49,9 @@ defmodule GettextTest.TranslatorWithDuckInterpolator.Interpolator do
       {:ok, "quack #{unquote(message)} #{inspect(unquote(bindings))} quack"}
     end
   end
+
+  @impl Gettext.Interpolation
+  def message_format, do: "duck-format"
 end
 
 defmodule GettextTest.TranslatorWithDuckInterpolator do