gatsby-plugin-cms-i18next

Use CMS provided translations for your Gatsby website

Features

• Based on gatsby-plugin-react-i18next, but uses the CMS for locales
• Seamless integration with react-i18next - a powerful internationalization framework for React.
• Code splitting. Load translations for each page separately.
• 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

The original plugin generated locale pages itself, rather than getting them from the CMS

How to use

Install package

yarn add @bond-london/gatsby-plugin-cms-i18next i18next react-i18next

Configure the plugin

// In your gatsby-config.js
plugins: [
  {
    resolve: `gatsby-source-filesystem`,
    options: {
      path: `${__dirname}/locales`,
      name: `locale`,
    },
  },
  {
    resolve: `@bond-london/gatsby-plugin-cms-i18next`,
    options: {
      localeJsonSourceName: `locale`, // name given to `gatsby-source-filesystem` plugin.
      defaultLanguage: `en`,
      // if you are using Helmet, you must include siteUrl, and make sure you add http:https
      siteUrl: `https://example.com/`,
      // you can pass any i18next options
      i18nextOptions: {
        interpolation: {
          escapeValue: false, // not needed for react as it escapes by default
        },
        keySeparator: false,
        nsSeparator: false,
      },
      pages: [
        {
          matchPath: "/:lang?/blog/:uid",
          getLanguageFromPath: true,
          excludeLanguages: ["es"],
        },
        {
          matchPath: "/preview",
          languages: ["en"],
        },
      ],
    },
  },
];

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
    |-- common.json
    |-- index.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-cms-i18next exposes all react-i18next methods and components.

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

import React from "react";
import { Link, Trans, useTranslation } from "gatsby-plugin-cms-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;

export const query = graphql`
  query ($language: String!) {
    locales: allLocale(filter: { language: { eq: $language } }) {
      edges {
        node {
          ns
          data
          language
        }
      }
    }
  }
`;

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-cms-i18next exposes useI18next hook

import { Link, useI18next } from "gatsby-plugin-cms-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-cms-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 | | --------------------------- | -------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | localeJsonSourceName | string | name of JSON translation file nodes that are loaded by gatsby-source-filesystem (set by option.name). Default is locale | | languages | string[] | supported language keys | | defaultLanguage | string | default language when visiting /page instead of /es/page | | generateDefaultLanguagePage | string | generate dedicated page for default language. e.g) /en/page. It is useful when you need page urls for all languages. For example, server-side redirect using Accept-Language header. Default is false. | | 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 | | pages | array | an array of page options used to modify plugin behaviour for specific pages | | i18nextOptions | object | i18next configuration options |

Page options

| Option | Type | Description | | ------------------- | ------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | matchPath | string | a path pattern like /:lang?/blog/:uid, check path-to-regexp for more info | | getLanguageFromPath | boolean | if set to true the language will be taken from the :lang param in the path instead of automatically generating a new page for each language | | excludeLanguages | array | an array of languages to exclude, if specified the plugin will not automatically generate pages for those languages, this option can be used to replace pages in some languages with custom ones | | languages | array | an array of languages, if specified the plugin will automatically generate pages only for those languages |

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-cms-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 exclude pages that already have language key in path

For example if you have some other plugin or script that generates your blog posts from headless CRM like prismic.io in different languages you would like to exclude those pages, to not generate duplicates for each language key. You can do that by providing pages option.

pages: [
  {
    matchPath: "/:lang?/blog/:uid",
    getLanguageFromPath: true,
    excludeLanguages: ["es"],
  },
];

You have to specify a :lang url param, so the plugin knows what part of the path should be treated as language key. In this example the plugin will automatically generate language pages for all languages except es. Assuming that you have ['en', 'es', 'de'] languages te blog post with the path /blog/hello-world you will have the following pages generated:

• /blog/hello-world - the English version (if you have en as a defaultLanguage)
• /es/blog/hello-world - the Spanish version that should exist before you run the plugin (created manually or at build time with a plugin or api call)
• /de/blog/hello-world - the German version that is generated automatically

Omit excludeLanguages to get all the languages form the path. Make sure that you have pages for all the languages that you specify in the plugin, otherwise you might have broken links.

How to exclude a page that should not be translated

You can limit the languages used to generate versions of a specific page, for exmaple to limit /preview page to only English version:

pages: [
  {
    matchPath: "/preview",
    languages: ["en"],
  },
];

How to fetch translations of specific namespaces only

You can use ns and language field in gatsby page queries to fetch specific namespaces that are being used in the page. This will be useful when you have several big pages with lots of translations.

export const query = graphql`
  query ($language: String!) {
    locales: allLocale(
      filter: { ns: { in: ["common", "index"] }, language: { eq: $language } }
    ) {
      edges {
        node {
          ns
          data
          language
        }
      }
    }
  }
`;

Note that in this case only files common.json and index.json will be loaded. This plugin will automatically add all loaded namespaces as fallback namespaces so if you don't specify a namespace in your translations they will still work.

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,
          };
        });
      },
    },
  },
];

Credits

This package is based on:

• gatsby-plugin-intl by Daewoong Moon
• gatsby-i18n-plugin by ikhudo
• gatsby-plugin-react-i18next by microapps

License

MIT © Bond London