aprs.me/lib/aprsme_web/plugs/set_locale.ex
2025-07-07 16:29:38 -05:00

50 lines
1.2 KiB
Elixir

defmodule AprsmeWeb.Plugs.SetLocale do
@moduledoc """
A plug that sets the locale based on the Accept-Language header.
Falls back to English if the requested locale is not available.
"""
import Plug.Conn
def init(opts), do: opts
def call(conn, _opts) do
locale = get_locale_from_header(conn) || "en"
# Set the backend's locale for the current process
Gettext.put_locale(AprsmeWeb.Gettext, locale)
# Store locale in session for LiveView to access
conn = put_session(conn, :locale, locale)
conn
end
defp get_locale_from_header(conn) do
case get_req_header(conn, "accept-language") do
[accept_language | _] ->
parse_accept_language(accept_language)
_ ->
nil
end
end
defp parse_accept_language(accept_language) do
accept_language
|> String.split(",")
|> Enum.map(&parse_language_tag/1)
|> Enum.filter(&supported_locale?/1)
|> List.first()
end
defp parse_language_tag(tag) do
tag
|> String.trim()
|> String.split(";")
|> List.first()
|> String.split("-")
|> List.first()
|> String.downcase()
end
defp supported_locale?(locale) do
locale in ~w(en es fr de)
end
end