i18next-http-middleware/cjs/languageLookups/header.js

i18next-http-middleware is a middleware to be used with Node.js web frameworks like express or Fastify and also for Deno.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = void 0;
var specialCases = ['hans', 'hant', 'latn', 'cyrl', 'cans', 'mong', 'arab', '419'];
var _default = exports.default = {
  name: 'header',
  lookup: function lookup(req, res, options) {
    var found;
    if (typeof req !== 'undefined') {
      var headers = options.getHeaders(req);
      if (!headers) return found;
      var locales = [];
      var acceptLanguage = options.lookupHeader ? headers[options.lookupHeader] : headers['accept-language'];
      if (acceptLanguage) {
        var lookupRegex = /(([a-z]{2,3})-?([A-Z]{2})?)\s*;?\s*(q=([0-9.]+))?/gi;
        if (acceptLanguage.indexOf('-') > 0) {
          var foundSpecialCase = specialCases.find(function (s) {
            return acceptLanguage.toLowerCase().indexOf("-".concat(s)) > 0;
          });
          if (foundSpecialCase) lookupRegex = /(([a-z]{2,3})-?([A-Z0-9]{2,4})?)\s*;?\s*(q=([0-9.]+))?/gi;
        }
        var lngs = [];
        var i;
        var m;
        var rgx = options.lookupHeaderRegex || lookupRegex;
        do {
          m = rgx.exec(acceptLanguage);
          if (m) {
            var lng = m[1];
            var weight = m[5] || '1';
            var q = Number(weight);
            if (lng && !isNaN(q)) {
              lngs.push({
                lng: lng,
                q: q
              });
            }
          }
        } while (m);
        lngs.sort(function (a, b) {
          return b.q - a.q;
        });
        for (i = 0; i < lngs.length; i++) {
          locales.push(lngs[i].lng);
        }
        if (locales.length) found = locales;
      }
    }
    return found;
  }
};
module.exports = exports.default;