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ICCHA Technologies
ICCHA Technologies

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Internationalization with ReactJS and i18n

There are a lot of languages around the world, any person should be able to understand the content of our page, the aim of internationalization is to remove the barriers to localizing or deploying an application internationally.

Solution

Use React i18next https://www.i18next.com/ and https://github.com/isaachinman/next-i18next to add internationalization to your React applications.

Recipe

For NextJS

  1. Initialize your NextJS project see https://nextjs.org/docs/getting-started documentation

  2. Install the i18n package, this time as recommendation use "next-i18next"

    Using npm

      # npm
      $ npm install next-i18next
    

    Using yarn

      # yarn
      $ yarn add next-i18next
    
  3. Create the next-i18next configuration file as "next-i18next.config.js" in the main folder, it might contain the locale configuration matching the one added in the next config file.

    module.exports = {
      i18n: {
        locales: ["en", "es"],
        defaultLocale: "en", // default locale will fallback to 'en'
      },
    };
    

You need to specify the routes that next will allow, this time only English and Spanish are going to be used.

  1. Configure the next config file "next.config.js", next has it own route specified in the locale value, as we already configured it in the next-i18next config file we
    only need to import it.

    const { i18n } = require("./next-i18next.config.js");
    const nextConfig = {
      reactStrictMode: true,
      i18n,
    };
    
    module.exports = nextConfig;
    

    for changing the language open the link referring to /en or /es

  2. Add the wrapper component "appWithTranslation" into the app file, it allows us to use the t (translate) function in our components via hooks.

    import { appWithTranslation } from "next-i18next";
    
    function MyApp({ Component, pageProps }) {
      return <Component {...pageProps} />;
    }
    
    export default appWithTranslation(MyApp);
    
  3. Create the translation files, by default, next-i18next expects your translations to be organized as such:

    .
    └── public    
        └── locales
            ├── en
            |   └── common.json
            └── es
                └── common.json
    

    see the public > locales > en > common.js file

    {
      "title": "i18n NextJS project",
      "spanish": "Spanish",
      "english": "English"
    }
    

    see the public > locales > es > common.js file

    {
      "title": "Proyecto i18n NextJS",
      "spanish": "Español",
      "english": "Ingles"
    }
    
  4. Then we add "serverSideTranslation" to getStaticProps or getServerSideProps (depending on your case) in our page-level components. In this case we will use the "serverSideTranslation" one.

    import { serverSideTranslations } from "next-i18next/serverSideTranslations";
    
    export async function getStaticProps({ locale }) {
      return {
        props: {
          ...(await serverSideTranslations(locale, ["common"])), //['common', 'other'] if more files are needed
          // Will be passed to the page component as props
        },
      };
    }
    

    This code need to be added in every file using the translations.

  5. Start using the translations by first importing the next-i18next package in the desired component

    import { useTranslation } from "next-i18next";
    

    Then create the const inside the respective component where the text will be translated

    const { t } = useTranslation("common");
    

    And this is how the translation is being used

    {t("title")}
    

    see a sample Home file:

    import Head from "next/head";
    import styles from "../styles/Home.module.css";
    
    import { serverSideTranslations } from "next-i18next/serverSideTranslations";
    import { useTranslation } from "next-i18next";
    
    const Home = () => {
      const { t } = useTranslation("common");
      return (
        <div className={styles.container}>
          <Head>
            <title>i18n NextJS project</title>
            <meta name="description" content="Generated by create next app" />
            <link rel="icon" href="/favicon.ico" />
          </Head>
    
          <main className={styles.main}>
            <h1 className={styles.title}>{t("title")}</h1>
    
            <div className={styles.grid}>
              <a href="/en" className={styles.card}>
                <p>{t("english")}</p>
              </a>
    
              <a href="/es" className={styles.card}>
                <p>{t("spanish")}</p>
              </a>
            </div>
          </main>
        </div>
      );
    };
    
    export async function getStaticProps({ locale }) {
      return {
        props: {
          ...(await serverSideTranslations(locale, ["common"])),
          // Will be passed to the page component as props
        },
      };
    }
    
    export default Home;
    

Feel free to check this codesanbox.io project

For React.js

  1. Create your react project

  2. Install the i18n required packages

    Using npm

      # npm
      $ npm install i18next --save
      $ npm install react-i18next i18next --save
      npm install i18next-browser-languagedetector
    

    Using yarn

      # yarn
      $ yarn add i18next
      $ yarn add react-i18next
      $ yarn add i18next-browser-languagedetector
    
  3. Create the translation file, it contains the languages and configuration, recommend to create a folder called "i18n" and inside a JS file called "i18n.js"

    import i18n from "i18next";
    import { initReactI18next } from "react-i18next";
    import LanguageDetector from "i18next-browser-languagedetector";
    
    i18n
      // detect user language
      // learn more: https://github.com/i18next/i18next-browser-languageDetector
      .use(LanguageDetector)
      // pass the i18n instance to react-i18next.
      .use(initReactI18next)
      // init i18next
      // for all options read: https://www.i18next.com/overview/configuration-options
      .init({
        debug: true,
        fallbackLng: "en",
        interpolation: {
          escapeValue: false, // not needed for react as it escapes by default
        },
        resources: {
          en: {
            translation: {
              title: "i18n React project",
              english: "English",
              spanish: "Spanish",
            },
          },
          es: {
            translation: {
              title: "Proyecto i18n en React",
              english: "Ingles",
              spanish: "Español",
            },
          },
        },
      });
    
    export default i18n;
    
    
  4. Import the i18n.js file to the index.js file

    import "./i18n/i18n";
    
  5. Start using the translations by first importing the react-i18next package in the desired component

    import { useTranslation } from 'react-i18next'
    

    Then create the const inside the respective component where the text will be translated

     const { t } = useTranslation()
    

    And this is how the translation is being used

      {t(title)}
    
  6. Finally Configure the changelanguage function at app.js component

    First get thi18n element from useTranslation

    const { t, i18n } = useTranslation(); // we used the t before
    

    now we can change the language bt using the changelanguage function:

    <button onClick={() => i18n.changeLanguage("en")} className="App-link">
      {t("english")}
    </button>
    <button onClick={() => i18n.changeLanguage("es")} className="App-link">
      {t("spanish")}
    </button>
    

Feel free to check this codesanbox.io project

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