rust-embedded · hwhsu1231 · Aug 5, 2026
@@ -1,12 +1,18 @@
 name: CI
 
 on:
+  schedule: # Build and deploy multilingual books weekly
+    - cron: '0 0 * * 1'
   push: # Run CI for all branches except GitHub merge queue tmp branches
     branches-ignore:
     - "gh-readonly-queue/**"
   pull_request: # Run CI for PRs on any branch
   merge_group: # Run CI for the GitHub merge queue
 
+env:
+  MDBOOK_VERSION: 0.5.1
+  MDBOOK_I18N_HELPERS_VERSION: 0.4.0
+
 jobs:
   build:
     runs-on: ubuntu-24.04
@@ -17,38 +23,68 @@ jobs:
       - name: Install Python dependencies
         run: |
           pip3 install --user python-dateutil linkchecker
+
       - name: Put pip binary directory into path
         run: echo "~/.local/bin" >> $GITHUB_PATH
 
-      - name: Cache Cargo installed binaries
-        uses: actions/cache@v4
-        id: cache-cargo
-        with:
-          path: ~/cargo-bin
-          key: cache-cargo
+      - name: Update rustup
+        run: rustup self update
+
+      - name: Install Rust
+        run: |
+          rustup set profile minimal
+          rustup toolchain install nightly -c rust-docs
+          rustup default nightly
+
       - name: Install mdbook
-        if: steps.cache-cargo.outputs.cache-hit != 'true'
-        uses: actions-rs/install@v0.1
-        with:
-          crate: mdbook
-          version: latest
-      - name: Copy mdbook to cache directory
-        if: steps.cache-cargo.outputs.cache-hit != 'true'
         run: |
-          mkdir ~/cargo-bin
-          cp ~/.cargo/bin/mdbook ~/cargo-bin
-      - name: Put new cargo binary directory into path
-        run: echo "~/cargo-bin" >> $GITHUB_PATH
+          cargo install mdbook --locked --version ${{ env.MDBOOK_VERSION }}
+
+      - name: Install mdbook-i18n-helpers
+        run: |
+          cargo install mdbook-i18n-helpers --locked --version ${{ env.MDBOOK_I18N_HELPERS_VERSION }}
+
+      - name: Download the .po files from localizethedocs/rust-embedded-book-l10n
+        run: |
+          git clone --branch po/master https://github.com/localizethedocs/rust-embedded-book-l10n.git po
+
+      - name: Build books
+        run: |
+          for langcode in $(jq -r '.languages[].code' switcher.json); do
+            echo "::group::Building $langcode"
+            langtag=$(jq -r --arg lang "$langcode" '.languages[] | select(.code == $lang) | .langtag' switcher.json)
+            MDBOOK_BOOK__LANGUAGE=$langcode mdbook build -d book/$langtag/
+            echo "::endgroup::"
+          done
 
-      - name: Build book
-        run: mdbook build
       - name: Test book
         run: mdbook test
+
       - name: Check links
         run: linkchecker book
 
+      - name: Create root index.html redirect
+        run: |
+          default_langtag=$(jq -r '.languages[] | select(.code == "en_US") | .langtag' switcher.json)
+          target="./${default_langtag}/"
+          cat > book/index.html << EOF
+          <!DOCTYPE html>
+          <html>
+          <head>
+            <meta http-equiv="refresh" content="0; url=${target}" />
+          </head>
+          <body>
+            <p>Redirecting to <a href="${target}">${target}</a></p>
+          </body>
+          </html>
+          EOF
+
+      - name: Copy switcher.json to book root
+        run: cp switcher.json book/
+
       - name: Deploy book
-        if: ${{ github.event_name == 'push' && github.ref == 'refs/heads/master' }}
+        if: ${{ ( github.event_name == 'push' && github.ref == 'refs/heads/master' ) ||
+                ( github.event_name == 'schedule' ) }}
         uses: peaceiris/actions-gh-pages@v3
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}

@@ -5,3 +5,13 @@ title = "The Embedded Rust Book"
 
 [output.html]
 git-repository-url = "https://github.com/rust-embedded/book"
+additional-css = [
+  "theme/css/switcher.css",
+]
+additional-js = [
+  "theme/js/switcher.js",
+]
+
+[preprocessor.gettext]
+optional = true
+after = ["links"]
@@ -0,0 +1,7 @@
+{
+  "languages": [
+    { "code": "en_US", "langtag": "en-us", "langname": "English" },
+    { "code": "zh_CN", "langtag": "zh-cn", "langname": "简体中文" },
+    { "code": "zh_TW", "langtag": "zh-tw", "langname": "繁體中文" }
+  ]
+}
@@ -0,0 +1,50 @@
+/* Ensure right-buttons uses flex alignment (mirrors cairo-book chrome.css) */
+.right-buttons {
+    display: flex;
+    align-items: center;
+    margin: 0 15px;
+}
+
+.right-buttons a {
+    text-decoration: none;
+}
+
+/* ---- Shared switcher styles ---- */
+
+.language-switcher,
+.version-switcher {
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+    margin-right: 10px;
+}
+
+/* Deterministic order: both switchers always leftmost, language before version */
+.language-switcher { order: -2; }
+.version-switcher  { order: -1; }
+
+.language-switcher label,
+.version-switcher label {
+    display: flex;
+    align-items: center;
+    font-size: 1.6rem;
+    color: var(--icons);
+    cursor: pointer;
+}
+
+.language-switcher select,
+.version-switcher select {
+    padding: 0.25rem 0.5rem;
+    border-radius: 4px;
+    border: 1px solid var(--icons);
+    background: var(--bg);
+    color: var(--icons);
+    font-size: 1.6rem;
+    cursor: pointer;
+}
+
+.language-switcher select:hover,
+.version-switcher select:hover {
+    border-color: var(--icons-hover);
+    color: var(--icons-hover);
+}
@@ -0,0 +1,129 @@
+(() => {
+    const fullPath = window.location.pathname;
+
+    // Derive siteRoot from a langtag segment (e.g. /xx-xx/) in the URL.
+    function deriveSiteRoot() {
+        const m = fullPath.match(/^(.+?)\/([a-z]{2}-[a-z]{2})\//);
+        return m ? m[1] : "";
+    }
+
+    const siteRoot = deriveSiteRoot();
+
+    function loadConfig() {
+        return fetch(siteRoot + "/switcher.json")
+            .then((r) => { if (!r.ok) throw new Error("not found"); return r.json(); })
+            .catch(() => null);
+    }
+
+    function whenReady(fn) {
+        if (document.readyState === "loading") {
+            document.addEventListener("DOMContentLoaded", fn);
+        } else {
+            fn();
+        }
+    }
+
+    whenReady(() => {
+        loadConfig().then((data) => {
+            if (!data) return;
+
+            const afterSite = fullPath.substring(siteRoot.length);
+            const parts = afterSite.split("/").filter(Boolean);
+
+            if (data.languages) renderLanguageSwitcher(data.languages, parts);
+            if (data.versions)  renderVersionSwitcher(data.versions, parts);
+        });
+    });
+
+    // ---- Language switcher ----
+
+    function renderLanguageSwitcher(languages, parts) {
+        const knownLangtags = new Set(languages.map((l) => l.langtag));
+
+        let currentLangtag = "";
+        let langtagIdx = -1;
+        for (let i = 0; i < parts.length; i++) {
+            if (knownLangtags.has(parts[i])) {
+                langtagIdx = i;
+                currentLangtag = parts[i];
+                break;
+            }
+        }
+        if (langtagIdx < 0) return;
+
+        const tail = "/" + parts.slice(langtagIdx + 1).join("/");
+
+        const container = document.createElement("div");
+        container.className = "language-switcher";
+        container.innerHTML =
+            '<label for="language-select" title="Language">' +
+            '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="1.25em" height="1.25em" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">' +
+            '<circle cx="12" cy="12" r="10"/><line x1="2" y1="12" x2="22" y2="12"/>' +
+            '<path d="M12 2a15.3 15.3 0 0 1 4 10 15.3 15.3 0 0 1-4 10 15.3 15.3 0 0 1-4-10 15.3 15.3 0 0 1 4-10z"/>' +
+            '</svg></label>' +
+            '<select id="language-select">' +
+            languages.map((lang) =>
+                '<option value="' + lang.langtag + '"' + (lang.langtag === currentLangtag ? ' selected' : '') + '>' +
+                lang.langname +
+                '</option>'
+            ).join("") +
+            '</select>';
+
+        insert(container);
+
+        document.getElementById("language-select").addEventListener("change", (e) => {
+            window.location.href = siteRoot + "/" + e.target.value + tail;
+        });
+    }
+
+    // ---- Version switcher ----
+
+    function renderVersionSwitcher(versions, parts) {
+        const knownVersions = new Set(versions.map((v) => v.version));
+        const defaultVersion = versions[0].version;
+
+        let currentVersion = defaultVersion;
+        let versionIdx = -1;
+        for (let i = 0; i < parts.length; i++) {
+            if (knownVersions.has(parts[i])) {
+                versionIdx = i;
+                currentVersion = parts[i];
+                break;
+            }
+        }
+        if (versionIdx < 0) return;
+
+        const prefix   = "/" + parts.slice(0, versionIdx).join("/");
+        const pagePath = "/" + parts.slice(versionIdx + 1).join("/");
+
+        const container = document.createElement("div");
+        container.className = "version-switcher";
+        container.innerHTML =
+            '<label for="version-select" title="Version">' +
+            '<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="1.25em" height="1.25em" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">' +
+            '<line x1="6" y1="3" x2="6" y2="15"/><circle cx="18" cy="6" r="3"/><circle cx="6" cy="18" r="3"/>' +
+            '<path d="M18 9a9 9 0 0 1-9 9"/>' +
+            '</svg></label>' +
+            '<select id="version-select">' +
+            versions.map((v) =>
+                '<option value="' + v.version + '"' + (v.version === currentVersion ? ' selected' : '') + '>' +
+                v.label +
+                '</option>'
+            ).join("") +
+            '</select>';
+
+        insert(container);
+
+        document.getElementById("version-select").addEventListener("change", (e) => {
+            const newVersion = e.target.value;
+            window.location.href = siteRoot + prefix + "/" + newVersion + pagePath;
+        });
+    }
+
+    function insert(container) {
+        const menuBar = document.querySelector(".right-buttons");
+        if (menuBar) {
+            menuBar.insertBefore(container, menuBar.firstChild);
+        }
+    }
+})();