@nuxtjs/i18n/dist/runtime/plugins/route-locale-detect.js

Internationalization for Nuxt

import { useNuxtI18nContext, useResolvedLocale } from "../context.js";
import { detectLocale, loadAndSetLocale, navigate } from "../utils.js";
import { addRouteMiddleware, defineNuxtPlugin, defineNuxtRouteMiddleware, useNuxtApp } from "#imports";
export default defineNuxtPlugin({
  name: "i18n:plugin:route-locale-detect",
  dependsOn: !__I18N_PRELOAD__ ? ["i18n:plugin"] : ["i18n:plugin", "i18n:plugin:preload"],
  async setup(_nuxt) {
    const nuxt = useNuxtApp(_nuxt._id);
    const ctx = useNuxtI18nContext(nuxt);
    const resolvedLocale = useResolvedLocale();
    await nuxt.runWithContext(
      () => loadAndSetLocale(
        nuxt,
        ctx.initial && resolvedLocale.value || detectLocale(nuxt, nuxt.$router.currentRoute.value)
      )
    );
    if (!__I18N_ROUTING__ || import.meta.server && __I18N_SERVER_REDIRECT__) return;
    addRouteMiddleware(
      "locale-changing",
      defineNuxtRouteMiddleware(async (to) => {
        const locale = await nuxt.runWithContext(() => loadAndSetLocale(nuxt, detectLocale(nuxt, to)));
        ctx.initial = false;
        return nuxt.runWithContext(() => navigate(nuxt, to, locale));
      }),
      { global: true }
    );
  }
});