facebook · lex111 · Jun 2, 2020 · May 31, 2020 · Jun 1, 2020
diff --git a/packages/docusaurus-theme-classic/src/theme/BlogPostItem/index.js b/packages/docusaurus-theme-classic/src/theme/BlogPostItem/index.js
@@ -9,8 +9,10 @@ import React from 'react';
 import classnames from 'classnames';
 import {MDXProvider} from '@mdx-js/react';
 
+import Head from '@docusaurus/Head';
 import Link from '@docusaurus/Link';
 import MDXComponents from '@theme/MDXComponents';
+import useBaseUrl from '@docusaurus/useBaseUrl';
 
 import styles from './styles.module.css';
 
@@ -38,12 +40,13 @@ function BlogPostItem(props) {
     isBlogPostPage = false,
   } = props;
   const {date, permalink, tags, readingTime} = metadata;
-  const {author, title} = frontMatter;
+  const {author, title, image} = frontMatter;
 
   const authorURL = frontMatter.author_url || frontMatter.authorURL;
   const authorTitle = frontMatter.author_title || frontMatter.authorTitle;
   const authorImageURL =
     frontMatter.author_image_url || frontMatter.authorImageURL;
+  const imageUrl = useBaseUrl(image, {absolute: true});
 
   const renderPostHeader = () => {
     const TitleHeading = isBlogPostPage ? 'h1' : 'h2';
@@ -92,38 +95,48 @@ function BlogPostItem(props) {
   };
 
   return (
-    <article className={!isBlogPostPage ? 'margin-bottom--xl' : undefined}>
-      {renderPostHeader()}
-      <section className="markdown">
-        <MDXProvider components={MDXComponents}>{children}</MDXProvider>
-      </section>
-      {(tags.length > 0 || truncated) && (
-        <footer className="row margin-vert--lg">
-          {tags.length > 0 && (
-            <div className="col">
-              <strong>Tags:</strong>
-              {tags.map(({label, permalink: tagPermalink}) => (
+    <>
+      <Head>
+        {image && <meta property="og:image" content={imageUrl} />}
+        {image && <meta property="twitter:image" content={imageUrl} />}
+        {image && (
+          <meta name="twitter:image:alt" content={`Image for ${title}`} />
+        )}
+      </Head>
+
+      <article className={!isBlogPostPage ? 'margin-bottom--xl' : undefined}>
+        {renderPostHeader()}
+        <section className="markdown">
+          <MDXProvider components={MDXComponents}>{children}</MDXProvider>
+        </section>
+        {(tags.length > 0 || truncated) && (
+          <footer className="row margin-vert--lg">
+            {tags.length > 0 && (
+              <div className="col">
+                <strong>Tags:</strong>
+                {tags.map(({label, permalink: tagPermalink}) => (
+                  <Link
+                    key={tagPermalink}
+                    className="margin-horiz--sm"
+                    to={tagPermalink}>
+                    {label}
+                  </Link>
+                ))}
+              </div>
+            )}
+            {truncated && (
+              <div className="col text--right">
                 <Link
-                  key={tagPermalink}
-                  className="margin-horiz--sm"
-                  to={tagPermalink}>
-                  {label}
+                  to={metadata.permalink}
+                  aria-label={`Read more about ${title}`}>
+                  <strong>Read More</strong>
                 </Link>
-              ))}
-            </div>
-          )}
-          {truncated && (
-            <div className="col text--right">
-              <Link
-                to={metadata.permalink}
-                aria-label={`Read more about ${title}`}>
-                <strong>Read More</strong>
-              </Link>
-            </div>
-          )}
-        </footer>
-      )}
-    </article>
+              </div>
+            )}
+          </footer>
+        )}
+      </article>
+    </>
   );
 }
 

diff --git a/packages/docusaurus-theme-classic/src/theme/DocItem/index.js b/packages/docusaurus-theme-classic/src/theme/DocItem/index.js
@@ -8,7 +8,6 @@
 import React from 'react';
 
 import Head from '@docusaurus/Head';
-import isInternalUrl from '@docusaurus/isInternalUrl';
 import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
 import useBaseUrl from '@docusaurus/useBaseUrl';
 import DocPaginator from '@theme/DocPaginator';
@@ -80,10 +79,7 @@ function DocItem(props) {
   } = DocContent;
 
   const metaTitle = title ? `${title} | ${siteTitle}` : siteTitle;
-  let metaImageUrl = siteUrl + useBaseUrl(metaImage);
-  if (!isInternalUrl(metaImage)) {
-    metaImageUrl = metaImage;
-  }
+  const metaImageUrl = useBaseUrl(metaImage, {absolute: true});
 
   return (
     <>

diff --git a/packages/docusaurus-theme-classic/src/theme/Footer/index.js b/packages/docusaurus-theme-classic/src/theme/Footer/index.js
@@ -15,7 +15,7 @@ import styles from './styles.module.css';
 
 function FooterLink({to, href, label, prependBaseUrlToHref, ...props}) {
   const toUrl = useBaseUrl(to);
-  const normalizedHref = useBaseUrl(href, true);
+  const normalizedHref = useBaseUrl(href, {forcePrependBaseUrl: true});
 
   return (
     <Link

diff --git a/packages/docusaurus-theme-classic/src/theme/Layout/index.js b/packages/docusaurus-theme-classic/src/theme/Layout/index.js
@@ -7,7 +7,6 @@
 
 import React from 'react';
 import Head from '@docusaurus/Head';
-import isInternalUrl from '@docusaurus/isInternalUrl';
 import useDocusaurusContext from '@docusaurus/useDocusaurusContext';
 import useBaseUrl from '@docusaurus/useBaseUrl';
 
@@ -39,13 +38,8 @@ function Layout(props) {
     version,
   } = props;
   const metaTitle = title ? `${title} | ${siteTitle}` : siteTitle;
-
   const metaImage = image || defaultImage;
-  let metaImageUrl = siteUrl + useBaseUrl(metaImage);
-  if (!isInternalUrl(metaImage)) {
-    metaImageUrl = metaImage;
-  }
-
+  const metaImageUrl = useBaseUrl(metaImage, {absolute: true});
   const faviconUrl = useBaseUrl(favicon);
 
   return (

diff --git a/packages/docusaurus-theme-classic/src/theme/Navbar/index.js b/packages/docusaurus-theme-classic/src/theme/Navbar/index.js
@@ -32,7 +32,7 @@ function NavLink({
 }) {
   const toUrl = useBaseUrl(to);
   const activeBaseUrl = useBaseUrl(activeBasePath);
-  const normalizedHref = useBaseUrl(href, true);
+  const normalizedHref = useBaseUrl(href, {forcePrependBaseUrl: true});
 
   return (
     <Link

diff --git a/packages/docusaurus/src/client/exports/__tests__/useBaseUrl.ts b/packages/docusaurus/src/client/exports/__tests__/useBaseUrl.ts
@@ -16,6 +16,7 @@ describe('useBaseUrl', () => {
     mockedContext.mockImplementation(() => ({
       siteConfig: {
         baseUrl: '/',
+        url: 'https://v2.docusaurus.io',
       },
     }));
 
@@ -29,12 +30,19 @@ describe('useBaseUrl', () => {
     expect(useBaseUrl('/hello/byebye/')).toEqual('/hello/byebye/');
     expect(useBaseUrl('https://github.com')).toEqual('https://github.com');
     expect(useBaseUrl('//reactjs.org')).toEqual('//reactjs.org');
+    expect(useBaseUrl('https://site.com', {forcePrependBaseUrl: true})).toEqual(
+      '/https://site.com',
+    );
+    expect(useBaseUrl('/hello/byebye', {absolute: true})).toEqual(
+      'https://v2.docusaurus.io/hello/byebye',
+    );
   });
 
   test('non-empty base URL', () => {
     mockedContext.mockImplementation(() => ({
       siteConfig: {
         baseUrl: '/docusaurus/',
+        url: 'https://v2.docusaurus.io',
       },
     }));
 
@@ -48,5 +56,11 @@ describe('useBaseUrl', () => {
     expect(useBaseUrl('/hello/byebye/')).toEqual('/docusaurus/hello/byebye/');
     expect(useBaseUrl('https://github.com')).toEqual('https://github.com');
     expect(useBaseUrl('//reactjs.org')).toEqual('//reactjs.org');
+    expect(useBaseUrl('https://site.com', {forcePrependBaseUrl: true})).toEqual(
+      '/docusaurus/https://site.com',
+    );
+    expect(useBaseUrl('/hello/byebye', {absolute: true})).toEqual(
+      'https://v2.docusaurus.io/docusaurus/hello/byebye',
+    );
   });
 });
diff --git a/packages/docusaurus/src/client/exports/useBaseUrl.ts b/packages/docusaurus/src/client/exports/useBaseUrl.ts
@@ -6,13 +6,20 @@
  */
 
 import useDocusaurusContext from './useDocusaurusContext';
+import isInternalUrl from './isInternalUrl';
+
+type BaseUrlOptions = {
+  forcePrependBaseUrl: boolean;
+  absolute: boolean;
+};
 
 export default function useBaseUrl(
   url: string,
-  forcePrependBaseUrl: boolean = false,
+  {forcePrependBaseUrl = false, absolute = false}: Partial<BaseUrlOptions> = {},
 ): string {
-  const {siteConfig} = useDocusaurusContext();
-  const {baseUrl = '/'} = siteConfig || {};
+  const {
+    siteConfig: {baseUrl = '/', url: siteUrl} = {},
+  } = useDocusaurusContext();
 
   if (!url) {
     return url;
@@ -22,14 +29,11 @@ export default function useBaseUrl(
     return baseUrl + url;
   }
 
-  const externalRegex = /^(https?:|\/\/)/;
-  if (externalRegex.test(url)) {
+  if (!isInternalUrl(url)) {
     return url;
   }
 
-  if (url.startsWith('/')) {
-    return baseUrl + url.slice(1);
-  }
+  const basePath = baseUrl + url.replace(/^\//, '');
 
-  return baseUrl + url;
+  return absolute ? siteUrl + basePath : basePath;
 }
diff --git a/website/docs/blog.md b/website/docs/blog.md
@@ -38,6 +38,7 @@ author_title: Co-creator of Docusaurus 1
 author_url: https://github.com/JoelMarcey
 author_image_url: https://graph.facebook.com/611217057/picture/?height=200&width=200
 tags: [hello, docusaurus-v2]
+image: https://i.imgur.com/mErPwqL.png
 ---
 Welcome to this blog. This blog is created with [**Docusaurus 2 alpha**](https://v2.docusaurus.io/).
 
@@ -59,6 +60,7 @@ The only required field is `title`; however, we provide options to add author in
 - `title` - The blog post title.
 - `tags` - A list of strings to tag to your post.
 - `draft` - A boolean flag to indicate that the blog post is work in process and therefore should not be published yet. However, draft blog posts will be displayed during development.
+- `image`: Cover or thumbnail image that will be used when displaying the link to your post.
 
 ## Summary truncation
 

diff --git a/website/docs/docusaurus-core.md b/website/docs/docusaurus-core.md
@@ -153,6 +153,13 @@ const Test = () => {
 
 React hook to automatically prepend `baseUrl` to a string automatically. This is particularly useful if you don't want to hardcode your config's `baseUrl`. We highly recommend you to use this.
 
+```ts
+type BaseUrlOptions = {
+  forcePrependBaseUrl: boolean;
+  absolute: boolean;
+};
+```
+
 Example usage:
 
 ```jsx {3,11}