IntlayerとTanstack Startによる国際化（i18n）入門

// src/routes/{-$locale}/route.tsximport { createFileRoute, Navigate, Outlet } from "@tanstack/react-router";import { configuration } from "intlayer";import { IntlayerProvider, useLocale } from "react-intlayer";import { useI18nHTMLAttributes } from "@/hooks/useI18nHTMLAttributes";export const Route = createFileRoute("/{-$locale}")({  component: LayoutComponent,});function LayoutComponent() {  const { locale } = Route.useParams();  return (    <IntlayerProvider locale={locale}>      <Outlet />    </IntlayerProvider>  );}

import type { Dictionary } from "intlayer";import { t } from "intlayer";const appContent = {  content: {    links: {      about: t({        en: "About",        es: "Acerca de",        fr: "À propos",      }),      home: t({        en: "ホーム",        es: "Inicio",        fr: "Accueil",      }),    },    meta: {      description: t({        en: "これは Intlayer と TanStack Router を使用した例です",        es: "Este es un ejemplo de uso de Intlayer con TanStack Router",        fr: "Ceci est un exemple d'utilisation d'Intlayer avec TanStack Router",      }),    },    title: t({      en: "Intlayer + TanStack Router へようこそ",      es: "Bienvenido a Intlayer + TanStack Router",      fr: "Bienvenue à Intlayer + TanStack Router",    }),  },  key: "app",} satisfies Dictionary;export default appContent;

// src/components/localized-link.tsx// eslint-disable-next-line no-restricted-importsimport { Link, type LinkProps } from "@tanstack/react-router";import { getLocalizedUrl } from "intlayer";import { useLocale } from "react-intlayer";type LocalizedLinkProps = {  to: string;} & Omit<LinkProps, "to">;export function LocalizedLink(props: LocalizedLinkProps) {  const { locale } = useLocale();  const isExternal = (to: string) => {    return /^(https?:)?\/\//.test(to);  };  const to = isExternal(props.to)    ? props.to    : getLocalizedUrl(props.to, locale);  return <Link {...props} to={to as LinkProps["to"]} />;}

// src/hooks/useLocalizedNavigate.tsx// eslint-disable-next-line no-restricted-importsimport { NavigateOptions, useNavigate } from "@tanstack/react-router";import { getLocalizedUrl } from "intlayer";import { useLocale } from "react-intlayer";type LocalizedNavigateOptions = {  to: string;} & Omit<NavigateOptions, "to">;export const useLocalizedNavigate = () => {  const navigate = useNavigate();  const { locale } = useLocale();  const isExternal = (to: string) => {    return /^(https?:)?\/\//.test(to);  };  const localizedNavigate = (options: LocalizedNavigateOptions) => {    const to = isExternal(options.to)      ? options.to      : getLocalizedUrl(options.to, locale);    navigate({ ...options, to: to as NavigateOptions["to"] });  };  return localizedNavigate;};

// src/routes/page.tsximport { useLocale } from "react-intlayer";import { Navigate } from "react-router";export default function Page() {  const { locale } = useLocale();  return <Navigate replace to={locale} />;}

import { createFileRoute } from "@tanstack/react-router";import { getIntlayer } from "intlayer";import { useIntlayer } from "react-intlayer";import LocaleSwitcher from "@/components/locale-switcher";import { LocalizedLink } from "@/components/localized-link";import { useLocalizedNavigate } from "@/hooks/useLocalizedNavigate";export const Route = createFileRoute("/{-$locale}/")({  component: RouteComponent,  head: ({ params }) => {    const { locale } = params;    const metaContent = getIntlayer("app", locale);    return {      meta: [        { title: metaContent.title },        { content: metaContent.meta.description, name: "description" },      ],    };  },});function RouteComponent() {  const content = useIntlayer("app");  const navigate = useLocalizedNavigate();  return (    <div className="grid place-items-center h-screen">      <div className="flex flex-col gap-4 items-center text-center">        {content.title}        <LocaleSwitcher />        <div className="flex gap-4">          <a href="/">インデックス</a>          <LocalizedLink to="/">{content.links.home}</LocalizedLink>          <LocalizedLink to="/about">{content.links.about}</LocalizedLink>        </div>        <div className="flex gap-4">          <button onClick={() => navigate({ to: "/" })}>            {content.links.home}          </button>          <button onClick={() => navigate({ to: "/about" })}>            {content.links.about}          </button>        </div>      </div>    </div>  );}

import { useLocation } from "@tanstack/react-router";import {  getHTMLTextDir,  getLocaleName,  getLocalizedUrl,  Locales,} from "intlayer";import { useIntlayer, useLocale } from "react-intlayer";export default function LocaleSwitcher() {  const { pathname, searchStr } = useLocation();  const content = useIntlayer("locale-switcher");  const { availableLocales, locale, setLocale } = useLocale({    onLocaleChange: (newLocale) => {      const pathWithLocale = getLocalizedUrl(pathname + searchStr, newLocale);      location.replace(pathWithLocale);    },  });  return (    <select      aria-label={content.label.toString()}      onChange={(e) => setLocale(e.target.value)}      value={locale}    >      {availableLocales.map((localeItem) => (        <option          dir={getHTMLTextDir(localeItem)}          key={localeItem}          lang={localeItem}          value={localeItem}        >          {/* 例: Français (フランス語) */}          {getLocaleName(localeItem, locale)} (          {getLocaleName(localeItem, Locales.ENGLISH)})        </option>      ))}    </select>  );}

// src/hooks/useI18nHTMLAttributes.tsximport { getHTMLTextDir } from "intlayer";import { useEffect } from "react";import { useLocale } from "react-intlayer";export const useI18nHTMLAttributes = () => {  const { locale } = useLocale();  useEffect(() => {    document.documentElement.lang = locale; // HTMLのlang属性を設定    document.documentElement.dir = getHTMLTextDir(locale); // HTMLのdir属性を設定  }, [locale]);};

import { createFileRoute, Navigate, Outlet } from "@tanstack/react-router";import { configuration } from "intlayer";import { IntlayerProvider, useLocale } from "react-intlayer";import { useI18nHTMLAttributes } from "@/hooks/useI18nHTMLAttributes"; // フックをインポートexport const Route = createFileRoute("/{-$locale}")({  component: LayoutComponent,});function LayoutComponent() {  useI18nHTMLAttributes(); // この行を追加  const { locale } = Route.useParams();  return (    <IntlayerProvider locale={locale}>      <Outlet />    </IntlayerProvider>  );}