docs: v0.2 canonical (#26514)

langchain-ai · Sep 16, 2024 · 7d2753f · 7d2753f
1 parent cfd11b2
commit 7d2753f
Showing 1 changed file with 120 additions and 0 deletions.
diff --git a/docs/src/theme/SiteMetadata/index.js b/docs/src/theme/SiteMetadata/index.js
@@ -0,0 +1,120 @@
+import React from 'react';
+import Head from '@docusaurus/Head';
+import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
+import useBaseUrl from '@docusaurus/useBaseUrl';
+import {PageMetadata, useThemeConfig} from '@docusaurus/theme-common';
+import {
+  DEFAULT_SEARCH_TAG,
+  useAlternatePageUtils,
+  keyboardFocusedClassName,
+} from '@docusaurus/theme-common/internal';
+import {useLocation} from '@docusaurus/router';
+import {applyTrailingSlash} from '@docusaurus/utils-common';
+import SearchMetadata from '@theme/SearchMetadata';
+// TODO move to SiteMetadataDefaults or theme-common ?
+// Useful for i18n/SEO
+// See https://developers.google.com/search/docs/advanced/crawling/localized-versions
+// See https://github.com/facebook/docusaurus/issues/3317
+function AlternateLangHeaders() {
+  const {
+    i18n: {defaultLocale, localeConfigs},
+  } = useDocusaurusContext();
+  const alternatePageUtils = useAlternatePageUtils();
+  // Note: it is fine to use both "x-default" and "en" to target the same url
+  // See https://www.searchviu.com/en/multiple-hreflang-tags-one-url/
+  return (
+    <Head>
+      {Object.entries(localeConfigs).map(([locale, {htmlLang}]) => (
+        <link
+          key={locale}
+          rel="alternate"
+          href={alternatePageUtils.createUrl({
+            locale,
+            fullyQualified: true,
+          })}
+          hrefLang={htmlLang}
+        />
+      ))}
+      <link
+        rel="alternate"
+        href={alternatePageUtils.createUrl({
+          locale: defaultLocale,
+          fullyQualified: true,
+        })}
+        hrefLang="x-default"
+      />
+    </Head>
+  );
+}
+// Default canonical url inferred from current page location pathname
+function useDefaultCanonicalUrl() {
+  const {
+    siteConfig: {url: siteUrl, baseUrl, trailingSlash},
+  } = useDocusaurusContext();
+  // TODO using useLocation().pathname is not a super idea
+  // See https://github.com/facebook/docusaurus/issues/9170
+  const {pathname} = useLocation();
+  const baseUrlPathname = useBaseUrl(pathname);
+  const canonicalPathname = applyTrailingSlash(baseUrlPathname, {
+    trailingSlash,
+    baseUrl,
+  });
+  const canonicalPathnameNoVersion = canonicalPathname.startsWith('/v0.') ? "/"+canonicalPathname.split('/').slice(2).join('/') : canonicalPathname;
+  return siteUrl + canonicalPathnameNoVersion;
+}
+
+// TODO move to SiteMetadataDefaults or theme-common ?
+function CanonicalUrlHeaders({permalink}) {
+  const {
+    siteConfig: {url: siteUrl},
+  } = useDocusaurusContext();
+  const defaultCanonicalUrl = useDefaultCanonicalUrl();
+  const canonicalUrl = permalink
+    ? `${siteUrl}${permalink}`
+    : defaultCanonicalUrl;
+  return (
+    <Head>
+      <meta property="og:url" content={canonicalUrl} />
+      <link rel="canonical" href={canonicalUrl} />
+    </Head>
+  );
+}
+export default function SiteMetadata() {
+  const {
+    i18n: {currentLocale},
+  } = useDocusaurusContext();
+  // TODO maybe move these 2 themeConfig to siteConfig?
+  // These seems useful for other themes as well
+  const {metadata, image: defaultImage} = useThemeConfig();
+  return (
+    <>
+      <Head>
+        <meta name="twitter:card" content="summary_large_image" />
+        {/* The keyboard focus class name need to be applied when SSR so links
+        are outlined when JS is disabled */}
+        <body className={keyboardFocusedClassName} />
+      </Head>
+
+      {defaultImage && <PageMetadata image={defaultImage} />}
+
+      <CanonicalUrlHeaders />
+
+      <AlternateLangHeaders />
+
+      <SearchMetadata tag={DEFAULT_SEARCH_TAG} locale={currentLocale} />
+
+      {/*
+          It's important to have an additional <Head> element here, as it allows
+          react-helmet to override default metadata values set in previous <Head>
+          like "twitter:card". In same Head, the same meta would appear twice
+          instead of overriding.
+        */}
+      <Head>
+        {/* Yes, "metadatum" is the grammatically correct term */}
+        {metadata.map((metadatum, i) => (
+          <meta key={i} {...metadatum} />
+        ))}
+      </Head>
+    </>
+  );
+}