@winstrike/next-i18next-koa/dist/es/middlewares/next-i18next-middleware.js

The easiest way to translate your NextJs apps. With Koa support only. Forked from 'next-i18next'.

import koaI18nextMiddleware from 'koa-i18next-middleware-fixed';
import { parse } from 'url';
import pathMatch from 'path-match';
import { forceTrailingSlash, lngPathDetector } from '../utils';
import { localeSubpathOptions } from '../config/default-config';
const route = pathMatch();
export default function (nexti18next) {
  const {
    config,
    i18n
  } = nexti18next;
  const {
    allLanguages,
    ignoreRoutes,
    localeSubpaths
  } = config;
  const ignoreRegex = new RegExp(`^\/(?!${ignoreRoutes.map(x => x.replace('/', '')).join('|')}).*$`);
  const ignoreRoute = route(ignoreRegex);

  const isI18nRoute = url => ignoreRoute(url);

  const localeSubpathRoute = route(`/:lng(${allLanguages.join('|')})/*`);
  const middleware = []; // If not using server side language detection,
  // we need to manually set the language for
  // each request

  if (!config.serverLanguageDetection) {
    middleware.push(async ({
      request: req
    }, next) => {
      if (isI18nRoute(req.url)) {
        req.lng = config.defaultLanguage;
      }

      await next();
    });
  }

  middleware.push(koaI18nextMiddleware.getHandler(i18n, {
    ignoreRoutes,
    locals: 'req'
  }));

  if (localeSubpaths !== localeSubpathOptions.NONE) {
    middleware.push(async ({
      request: req,
      response: res
    }, next) => {
      if (isI18nRoute(req.url)) {
        const {
          pathname
        } = parse(req.url);

        if (allLanguages.some(lng => pathname === `/${lng}`)) {
          forceTrailingSlash(req, res, pathname.slice(1));
          return;
        }

        lngPathDetector(req, res);
        const params = localeSubpathRoute(req.url);

        if (params !== false) {
          const {
            lng
          } = params;
          req.query = { ...req.query,
            lng
          };
          req.url = req.url.replace(`/${lng}`, '');
        }
      }

      await next();
    });
  }

  return middleware;
}