feat: add metatags support for seo / blogposts #5373 (#5375)

* feat: add metatags support for seo / blogposts

* feat: different implementation

* feat: use isBlogPostPage

* feat: implement in BlogPostPage-remove Seo changes

* Revert "feat: implement in BlogPostPage-remove Seo changes"

This reverts commit 1cba459b

* Move Seo to BlogPostPage + some fixes

* fix social preview asset

* Fix blog social image + improve a bit Seo setup

* fix bootstrap theme

Co-authored-by: John <john.reilly@investec.co.uk>
Co-authored-by: slorber <lorber.sebastien@gmail.com>

packages/docusaurus-plugin-content-blog/index.d.ts

@@ -21,7 +21,7 @@ declare module '@theme/BlogSidebar' {
 }
 
 declare module '@theme/BlogPostPage' {
-  import type {TOCItem} from '@docusaurus/types';
+  import type {FrontMatterTag} from '@docusaurus/utils';
   import type {BlogSidebar} from '@theme/BlogSidebar';
 
   export type FrontMatter = {
@@ -29,7 +29,7 @@ declare module '@theme/BlogPostPage' {
     readonly title: string;
     readonly author?: string;
     readonly image?: string;
-    readonly tags?: readonly string[];
+    readonly tags?: readonly FrontMatterTag[];
     readonly keywords?: readonly string[];
     readonly author_url?: string;
     readonly authorURL?: string;

packages/docusaurus-plugin-content-docs/src/plugin-content-docs.d.ts

@@ -171,6 +171,7 @@ declare module '@theme/Seo' {
     readonly description?: string;
     readonly keywords?: readonly string[] | string;
     readonly image?: string;
+    readonly children?: ReactNode;
   };
 
   const Seo: (props: Props) => JSX.Element;

packages/docusaurus-theme-bootstrap/src/theme/DebugLayout/index.tsx

@@ -34,7 +34,7 @@ function Layout(props: Props): JSX.Element {
   const metaImage = image || defaultImage;
   let metaImageUrl = siteUrl + useBaseUrl(metaImage);
   if (!isInternalUrl(metaImage)) {
-    metaImageUrl = metaImage;
+    metaImageUrl = metaImage as string;
   }
   const faviconUrl = useBaseUrl(favicon);
 

packages/docusaurus-theme-bootstrap/src/theme/Layout/index.tsx

@@ -35,7 +35,7 @@ function Layout(props: Props): JSX.Element {
   const metaImage = image || defaultImage;
   let metaImageUrl = siteUrl + useBaseUrl(metaImage);
   if (!isInternalUrl(metaImage)) {
-    metaImageUrl = metaImage;
+    metaImageUrl = metaImage as string;
   }
   const faviconUrl = useBaseUrl(favicon);
 

packages/docusaurus-theme-classic/src/theme/BlogPostItem/index.tsx

@@ -13,7 +13,6 @@ import Link from '@docusaurus/Link';
 import {useBaseUrlUtils} from '@docusaurus/useBaseUrl';
 import {usePluralForm} from '@docusaurus/theme-common';
 import MDXComponents from '@theme/MDXComponents';
-import Seo from '@theme/Seo';
 import EditThisPage from '@theme/EditThisPage';
 import type {Props} from '@theme/BlogPostItem';
 
@@ -60,7 +59,7 @@ function BlogPostItem(props: Props): JSX.Element {
     title,
     editUrl,
   } = metadata;
-  const {author, keywords} = frontMatter;
+  const {author} = frontMatter;
 
   const image = frontMatterAssets.image ?? frontMatter.image;
 
@@ -129,9 +128,6 @@ function BlogPostItem(props: Props): JSX.Element {
   };
 
   return (
-    <>
-      <Seo {...{keywords, image}} />
-
     <article
       className={!isBlogPostPage ? 'margin-bottom--xl' : undefined}
       itemProp="blogPost"
@@ -140,10 +136,7 @@ function BlogPostItem(props: Props): JSX.Element {
       {renderPostHeader()}
 
       {image && (
-          <meta
+        <meta itemProp="image" content={withBaseUrl(image, {absolute: true})} />
-            itemProp="image"
-            content={withBaseUrl(image, {absolute: true})}
-          />
       )}
 
       <div className="markdown" itemProp="articleBody">
@@ -185,7 +178,6 @@ function BlogPostItem(props: Props): JSX.Element {
         </footer>
       )}
     </article>
-    </>
   );
 }
 

packages/docusaurus-theme-classic/src/theme/BlogPostPage/index.tsx

@@ -6,6 +6,7 @@
  */
 
 import React from 'react';
+import Seo from '@theme/Seo';
 import BlogLayout from '@theme/BlogLayout';
 import BlogPostItem from '@theme/BlogPostItem';
 import BlogPostPaginator from '@theme/BlogPostPaginator';
@@ -15,13 +16,14 @@ import {ThemeClassNames} from '@docusaurus/theme-common';
 function BlogPostPage(props: Props): JSX.Element {
   const {content: BlogPostContents, sidebar} = props;
   const {frontMatter, frontMatterAssets, metadata} = BlogPostContents;
-  const {title, description, nextItem, prevItem} = metadata;
+  const {title, description, nextItem, prevItem, date, tags} = metadata;
-  const {hide_table_of_contents: hideTableOfContents} = frontMatter;
+  const {hide_table_of_contents: hideTableOfContents, keywords} = frontMatter;
+
+  const image = frontMatterAssets.image ?? frontMatter.image;
+  const authorURL = frontMatter.author_url || frontMatter.authorURL;
 
   return (
     <BlogLayout
-      title={title}
-      description={description}
       wrapperClassName={ThemeClassNames.wrapper.blogPages}
       pageClassName={ThemeClassNames.page.blogPostPage}
       sidebar={sidebar}
@@ -30,6 +32,24 @@ function BlogPostPage(props: Props): JSX.Element {
           ? BlogPostContents.toc
           : undefined
       }>
+      <Seo
+        // TODO refactor needed: it's a bit annoying but Seo MUST be inside BlogLayout
+        // otherwise  default image (set by BlogLayout) would shadow the custom blog post image
+        title={title}
+        description={description}
+        keywords={keywords}
+        image={image}>
+        <meta property="og:type" content="article" />
+        <meta property="article:published_time" content={date} />
+        {authorURL && <meta property="article:author" content={authorURL} />}
+        {tags.length > 0 && (
+          <meta
+            property="article:tag"
+            content={tags.map((tag) => tag.label).join(',')}
+          />
+        )}
+      </Seo>
+
       <BlogPostItem
         frontMatter={frontMatter}
         frontMatterAssets={frontMatterAssets}
@@ -37,6 +57,7 @@ function BlogPostPage(props: Props): JSX.Element {
         isBlogPostPage>
         <BlogPostContents />
       </BlogPostItem>
+
       {(nextItem || prevItem) && (
         <BlogPostPaginator nextItem={nextItem} prevItem={prevItem} />
       )}

packages/docusaurus-theme-classic/src/theme/LayoutHead/index.tsx

@@ -104,13 +104,14 @@ export default function LayoutHead(props: Props): JSX.Element {
         {favicon && <link rel="shortcut icon" href={faviconUrl} />}
         <title>{pageTitle}</title>
         <meta property="og:title" content={pageTitle} />
-        {image ||
-          (defaultImage && (
         <meta name="twitter:card" content="summary_large_image" />
-          ))}
       </Head>
 
-      <Seo {...{description, keywords, image}} />
+      {/* image can override the default image */}
+      {defaultImage && <Seo image={defaultImage} />}
+      {image && <Seo image={image} />}
+
+      <Seo description={description} keywords={keywords} />
 
       <CanonicalUrlHeaders />
 

packages/docusaurus-theme-classic/src/theme/Seo/index.tsx

@@ -7,8 +7,8 @@
 
 import React from 'react';
 import Head from '@docusaurus/Head';
-import {useThemeConfig, useTitleFormatter} from '@docusaurus/theme-common';
+import {useTitleFormatter} from '@docusaurus/theme-common';
-import useBaseUrl from '@docusaurus/useBaseUrl';
+import {useBaseUrlUtils} from '@docusaurus/useBaseUrl';
 
 import type {Props} from '@theme/Seo';
 
@@ -17,10 +17,11 @@ export default function Seo({
   description,
   keywords,
   image,
+  children,
 }: Props): JSX.Element {
-  const {image: defaultImage} = useThemeConfig();
   const pageTitle = useTitleFormatter(title);
-  const pageImage = useBaseUrl(image || defaultImage, {absolute: true});
+  const {withBaseUrl} = useBaseUrlUtils();
+  const pageImage = image ? withBaseUrl(image, {absolute: true}) : undefined;
 
   return (
     <Head>
@@ -41,6 +42,8 @@ export default function Seo({
 
       {pageImage && <meta property="og:image" content={pageImage} />}
       {pageImage && <meta name="twitter:image" content={pageImage} />}
+
+      {children}
     </Head>
   );
 }

packages/docusaurus-theme-common/src/utils/useThemeConfig.ts

@@ -101,7 +101,7 @@ export type ThemeConfig = {
   prism: PrismConfig;
   footer?: Footer;
   hideableSidebar: boolean;
-  image: string;
+  image?: string;
   metadatas: Array<Record<string, string>>;
   sidebarCollapsible: boolean;
 };