acha-framework/src/backend/localize.js

is a modular framework on both client (angular.js) and server (node.js) side, it provides security, orm, ioc, obfuscation and ...

(function (undefined) {
  Ioc.define('backend.localize', ['backend.configuration'], function (provide, config) {
    const i18n = require('i18n');
    const getCulture = function (req) {
      if (req.originalUrl.length >= 3) {
        //matches /fa or /fa/
        req.params.lang = req.originalUrl.substring(1, 3);
      } else if (req.originalUrl === '/') {
        req.params.lang = config.i18n.def;
      }
      var lang = (req.params.lang || req.cookies.culture).toLowerCase();
      if (config.i18n.allowed.indexOf(lang) !== -1) {
        return lang;
      }
      return config.i18n.def;
    };
    const setCulture = function (req, res) {
      var lang = getCulture(req);
      req.setLocale(lang);
      res.cookie('culture', lang);
      return lang;
    };
    const cultureInfo = function (req, res) {
      'use strict';
      var lang = setCulture(req, res);
      switch (lang) {
      case 'fa':
      case 'ar':
        return {
          lang: lang,
          dir: 'rtl',
          rtl: true
        };
        break;
      default:
        return {
          lang: lang,
          dir: 'ltr',
          rtl: false
        };
        break;
      }
    };
    provide({
      getCulture: getCulture,
      setCulture: setCulture,
      cultureInfo: cultureInfo
    });
  });
}());