n4u_sample/apps/n2o_sample/src/hm.erl

-module(hm).

-compile([export_all, nowarn_export_all]).

%-include_lib("nitro/include/nitro.hrl").
-include_lib("n4u/include/wf.hrl").
%-include_lib("kernel/include/file.hrl").

%% help module

%% get params

% get_language_from_header(Req)
% get_language_from_cookies(Name, Req)
% get_language(Name, Req)
% get_tr_mod()

%% todo mv this funcs to framework

%% other
% assert_int(X)

%% get params

get_language_from_header(Req) ->
  #{headers := Headers} = Req,
  F1 = fun(K, V, Acc) ->
    Is_Same = <<"accept-language">> =:= string:lowercase(K),
    case Is_Same of
      true ->
        Is_A = <<"*">> =:= binary:part(V, {0, 1}),
        Is_E = <<>> =:= V,
        case {Is_A, Is_E} of
          {false, false} -> V;
          _ -> []
        end;
      _ -> Acc
    end
  end,
  Accept_language = maps:fold(F1, [], Headers),
  case Accept_language of
    [] -> en;
    Val ->
      <<Lang0:2/binary,_/binary>> = Val, %% Accept-Language: <<"uk,en;q=0.5">> %% <<"fr-CH, fr;q=0.9, en;q=0.8, de;q=0.7, *;q=0.5">>
      Lang = try erlang:binary_to_existing_atom(Lang0, latin1)
      catch _:_ -> en
      end,
      case lists:member(Lang, [en, uk]) of %% todo mv to config langs list and default lang
        false -> en;
        true -> Lang
      end
  end.


get_language_from_cookies(Name, Req) ->
  case wf:cookie_req(Name, Req) of
    undefined -> false;
    Lang ->
      case lists:member(Lang, [en, uk]) of
        false -> false;
        true -> Lang
      end
  end.


get_language(Name, Req) ->
  case ?MODULE:get_language_from_cookies(Name, Req) of
    false ->
      ?MODULE:get_language_from_header(Req);
    Lang ->
      Lang
  end.


get_tr_mod() -> %% modules with i18n for config langs list -- en -> tr_en, uk -> tr_uk etc
  Lang = get_language(<<"lang">>, ?REQ),
  case Lang of
    uk -> tr_uk;
    %en -> tr_en
    _ -> tr_en
  end. 


post_value(Req, Key) ->
  {ok, PostStr, _} = wf:request_body(Req),
  PostList = cow_qs:parse_qs(PostStr),
  ?MODULE:post_value2( [ Value || {_Key1, Value} <- PostList, _Key1 =:= Key ] ).

% helper
post_value2([]) -> undefined;
post_value2([Val|_]) -> Val;
post_value2(_) -> undefined.


assert_int(X) when erlang:is_integer(X) -> ok.