# Portions of this file are derived from Pleroma: # Pleroma: A lightweight social networking server # Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/> # SPDX-License-Identifier: AGPL-3.0-only # NOTE: this module is based on https://github.com/smeevil/set_locale defmodule Mobilizon.Web.Plugs.SetLocalePlug do @moduledoc """ Plug to set locale for Gettext """ import Plug.Conn, only: [assign: 3] alias Mobilizon.Web.Gettext, as: GettextBackend @spec init(any()) :: nil def init(_), do: nil @spec call(Plug.Conn.t(), any()) :: Plug.Conn.t() def call(conn, _) do locale = [ eventual_path_locale(conn.path_info), conn.assigns[:user_locale], conn.assigns[:detected_locale], default_locale(), "en" ] |> Enum.filter(& &1) |> Enum.map(&determine_best_locale/1) |> Enum.filter(&supported_locale?/1) |> hd() Gettext.put_locale(locale) assign(conn, :locale, locale) end defp eventual_path_locale(path_info) do with [locale] <- path_info, true <- supported_locale?(locale) do locale else _ -> nil end end @spec supported_locale?(String.t()) :: boolean() defp supported_locale?(locale) do GettextBackend |> Gettext.known_locales() |> Enum.member?(locale) end @spec default_locale :: String.t() defp default_locale do Keyword.get(Mobilizon.Config.instance_config(), :default_language, "en") end @doc """ Determine the best available locale for a given locale ID """ @spec determine_best_locale(String.t()) :: String.t() | nil def determine_best_locale(locale) when is_binary(locale) do locale = String.trim(locale) locales = Gettext.known_locales(GettextBackend) cond do locale == "" -> nil # Either it matches directly, eg: "en" => "en", "fr" => "fr" locale in locales -> locale # Either the first part matches, "fr_CA" => "fr" split_locale(locale) in locales -> split_locale(locale) # Otherwise set to default true -> nil end end def determine_best_locale(_), do: nil # Keep only the first part of the locale @spec split_locale(String.t()) :: String.t() defp split_locale(locale), do: locale |> String.split("_", trim: true, parts: 2) |> hd end