gatsby-plugin-react-i18next

gatsby-plugin-react-i18next

Easily translate your Gatsby website into multiple languages.

Features

• Seamless integration with react-i18next - a powerful internationalization framework for React.
• No extra graphql queries to fetch translations, everything is done automatically.
• Automatic redirection based on the user's preferred language in browser provided by browser-lang.
• Support multi-language url routes in a single page component. You don't have to create separate pages such as pages/en/index.js or pages/es/index.js.
• SEO friendly
• Support for gatsby-plugin-layout

Why?

When you build multilingual sites, Google recommends using different URLs for each language version of a page rather than using cookies or browser settings to adjust the content language on the page. (read more)

How is it different from other gatsby i18next plugins?

This plugin does not require fetching translations with graphql query on each page, everything is done automatically. Just use react-i18next to translate your pages.

Demo

• View demo online
• Source code

Used by

• monei.net
• moonmail.io

How to use

Install package

yarn add gatsby-plugin-react-i18next i18next react-i18next

or

npm install --save gatsby-plugin-react-i18next i18next react-i18next

Configure the plugin

// In your gatsby-config.js
plugins: [
  {
    resolve: `gatsby-plugin-react-i18next`,
    options: {
      path: `${__dirname}/locales`,
      languages: [`en`, `es`, `de`],
      defaultLanguage: `en`,

      // you can pass any i18next options
      // pass following options to allow message content as a key
      i18nextOptions: {
        interpolation: {
          escapeValue: false // not needed for react as it escapes by default
        },
        keySeparator: false,
        nsSeparator: false
      }
    }
  }
];

You'll also need to add language JSON resources to the project.

For example,

language resource files	language
/locales/en/translation.json	English
/locales/es/translation.json	Spanish
/locales/de/translation.json	German

You can use different namespaces to organize your translations. Use the following file structure:

|-- language
   |-- namespace.json

For example:

|-- en
    |-- header.json
    |-- footer.json

The default namespace is translation. Read more about i18next namespaces

Change your components

Use react i18next useTranslation react hook and Trans component to translate your pages.

gatsby-plugin-react-i18next exposes all react-i18next methods and components.

Replace Gatsby Link component with the Link component exported from gatsby-plugin-react-i18next

import React from 'react';
import {Link, Trans, useTranslation} from 'gatsby-plugin-react-i18next';
import Layout from '../components/layout';
import Image from '../components/image';
import SEO from '../components/seo';

const IndexPage = () => {
  const {t} = useTranslation();
  return (
    <Layout>
      <SEO title={t('Home')} />
      <h1>
        <Trans>Hi people</Trans>
      </h1>
      <p>
        <Trans>Welcome to your new Gatsby site.</Trans>
      </p>
      <p>
        <Trans>Now go build something great.</Trans>
      </p>
      <div style={{maxWidth: `300px`, marginBottom: `1.45rem`}}>
        <Image />
      </div>
      <Link to="/page-2/">
        <Trans>Go to page 2</Trans>
      </Link>
    </Layout>
  );
};

export default IndexPage;

and in locales/en/translations.json you will have

{
  "Home": "Home",
  "Hi people": "Hi people",
  "Welcome to your new Gatsby site.": "Welcome to your new Gatsby site.",
  "Now go build something great.": "Now go build something great.",
  "Go to page 2": "Go to page 2"
}

This example is not using semantic keys instead the entire message will be used as a key. Read more.

Changing the language

gatsby-plugin-react-i18next exposes useI18next hook

import {Link, useI18next} from 'gatsby-plugin-react-i18next';
import React from 'react';

const Header = ({siteTitle}) => {
  const {languages, changeLanguage} = useI18next();
  return (
    <header className="main-header">
      <h1 style={{margin: 0}}>
        <Link
          to="/"
          style={{
            color: `white`,
            textDecoration: `none`
          }}>
          {siteTitle}
        </Link>
      </h1>
      <ul className="languages">
        {languages.map((lng) => (
          <li key={lng}>
            <a
              href="#"
              onClick={(e) => {
                e.preventDefault();
                changeLanguage(lng);
              }}>
              {lng}
            </a>
          </li>
        ))}
      </ul>
    </header>
  );
};

Or a more SEO friendly version using Link component

import {Link, useI18next} from 'gatsby-plugin-react-i18next';
import PropTypes from 'prop-types';
import React from 'react';

const Header = ({siteTitle}) => {
  const {languages, originalPath} = useI18next();
  return (
    <header className="main-header">
      <h1 style={{margin: 0}}>
        <Link
          to="/"
          style={{
            color: `white`,
            textDecoration: `none`
          }}>
          {siteTitle}
        </Link>
      </h1>
      <ul className="languages">
        {languages.map((lng) => (
          <li key={lng}>
            <Link to={originalPath} language={lng}>
              {lng}
            </Link>
          </li>
        ))}
      </ul>
    </header>
  );
};

Plugin Options

Option	Type	Description
path	string	path to the folder with JSON translations
languages	string[]	supported language keys
defaultLanguage	string	default language when visiting /page instead of /es/page
redirect	boolean	if the value is true, / or /page-2 will be redirected to the user's preferred language router. e.g) /es or /es/page-2. Otherwise, the pages will render defaultLangugage language. Default is true
siteUrl	string	public site url, is used to generate language specific meta tags
i18nextOptions	object	i18next configuration options

Plugin API

Link

Link component is identical to Gatsby Link component except that you can provide additional language prop to create a link to a page with different language

import {Link} from 'gatsby-plugin-react-i18next';

const SpanishAboutLink = () => (
  <Link to="/about" language="es">
    About page in Spanish
  </Link>
);

Helmet

Helmet component is identical to gatsby-plugin-react-helmet component but also provides language related metatags (alternative and canonical links)

Note! To use it you need to have react-helmet dependency installed. You also need to provide siteUrl in plugin options for it to work properly.

I18nextContext

Use this react context to access language information about the page

const context = React.useContext(I18nextContext);

Content of the context object

Attribute	Type	Description
language	string	current language
languages	string[]	supported language keys
routed	boolean	if false it means that the page is in default language
defaultLanguage	string	default language provided in plugin options
originalPath	string	page path in default language
path	string	page path
siteUrl	string	public site url provided in plugin options

The same context will be also available in the Gatsby pageContext.i18n object

useI18next

This react hook returns I18nextContext, object and additional helper functions

Function	Description
navigate	This is a wrapper around Gatsby navigate helper function that will navigate to the page in selected language
changeLanguage	A helper function to change language. The first parameter is a language code. Signature: (language: string, to?: string, options?: NavigateOptions) => Promise<void>. You can pass additional parameters to navigate to different page.

useI18next also exposes the output of react i18next useTranslation so you can use

const {t} = useI18next();

How to fetch language specific data

You can use language variable in gatsby page queries to fetch additional data for each language. For example if you're using gatsby-transformer-json your query might look like:

export const query = graphql`
  query($language: String!) {
    dataJson(language: {eq: $language}) {
      ...DataFragment
    }
  }
`;

How to add sitemap.xml for all language specific pages

You can use gatsby-plugin-sitemap to automatically generate a sitemap during build time. You need to customize query to fetch only original pages and then serialize data to build a sitemap. Here is an example:

// In your gatsby-config.js
plugins: [
  {
    resolve: 'gatsby-plugin-sitemap',
    options: {
      exclude: ['/**/404', '/**/404.html'],
      query: `
          {
            site {
              siteMetadata {
                siteUrl
              }
            }
            allSitePage(filter: {context: {i18n: {routed: {eq: false}}}}) {
              edges {
                node {
                  context {
                    i18n {
                      defaultLanguage
                      languages
                      originalPath
                    }
                  }
                  path
                }
              }
            }
          }
        `,
      serialize: ({site, allSitePage}) => {
        return allSitePage.edges.map((edge) => {
          const {languages, originalPath, defaultLanguage} = edge.node.context.i18n;
          const {siteUrl} = site.siteMetadata;
          const url = siteUrl + originalPath;
          const links = [
            {lang: defaultLanguage, url},
            {lang: 'x-default', url}
          ];
          languages.forEach((lang) => {
            if (lang === defaultLanguage) return;
            links.push({lang, url: `${siteUrl}/${lang}${originalPath}`});
          });
          return {
            url,
            changefreq: 'daily',
            priority: originalPath === '/' ? 1.0 : 0.7,
            links
          };
        });
      }
    }
  }
];

How to extract translations from pages

You can use babel-plugin-i18next-extract automatically extract translations inside t function and Trans component from you pages and save them in JSON.

1. Install

yarn add @babel/cli @babel/plugin-transform-typescript babel-plugin-i18next-extract -D

1. create babel-extract.config.js file (don't name it babel.config.js, or it will be used by gatsby)

module.exports = {
  presets: ['babel-preset-gatsby'],
  plugins: [
    [
      'i18next-extract',
      {
        keySeparator: null,
        nsSeparator: null,
        keyAsDefaultValue: ['en'],
        useI18nextDefaultValue: ['en'],
        discardOldKeys: true,
        outputPath: 'locales/{{locale}}/{{ns}}.json',
        customTransComponents: [['gatsby-plugin-react-i18next', 'Trans']]
      }
    ]
  ],
  overrides: [
    {
      test: [`**/*.ts`, `**/*.tsx`],
      plugins: [[`@babel/plugin-transform-typescript`, {isTSX: true}]]
    }
  ]
};

1. add a script to your package.json

{
  "scripts": {
    "extract": "yarn run babel --config-file ./babel-extract.config.js -o tmp/chunk.js 'src/**/*.{js,jsx,ts,tsx}' && rm -rf tmp"
  }
}

Automatically translate to different languages

After your messages had been extracted you can use AWS Translate to automatically translate messages to different languages.

This functionality is out of the scope of this plugin, but you can get the idea from this script

Credits

This package is based on:

• gatsby-plugin-intl by Daewoong Moon
• gatsby-i18n-plugin by ikhudo

License

MIT © microapps