feat(theme-classic, plugin-docs): sidebar item level-specific className + allow customization (#5642)

* Initial work

* Complete function

* Avoid duplication

* More dedupe

* Make everything constants

* Change casing & docs

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

@@ -29,6 +29,7 @@ const DocFrontMatterSchema = Joi.object<DocFrontMatter>({
   slug: Joi.string(),
   sidebar_label: Joi.string(),
   sidebar_position: Joi.number(),
+  sidebar_class_name: Joi.string(),
   tags: FrontMatterTagsSchema,
   pagination_label: Joi.string(),
   custom_edit_url: URISchema.allow('', null),

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

@@ -30,6 +30,7 @@ declare module '@docusaurus/plugin-content-docs-types' {
   };
 
   type PropsSidebarItemBase = {
+    className?: string;
     customProps?: Record<string, unknown>;
   };
 

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

@@ -47,6 +47,7 @@ Available document ids are:
       type: 'link',
       label: sidebarLabel || item.label || title,
       href: permalink,
+      className: item.className,
       customProps: item.customProps,
     };
   };

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

@@ -30,6 +30,7 @@ export type CategoryMetadatasFile = {
   position?: number;
   collapsed?: boolean;
   collapsible?: boolean;
+  className?: string;
 
   // TODO should we allow "items" here? how would this work? would an "autogenerated" type be allowed?
   // This mkdocs plugin do something like that: https://github.com/lukasgeiter/mkdocs-awesome-pages-plugin/
@@ -44,6 +45,7 @@ const CategoryMetadatasFileSchema = Joi.object<CategoryMetadatasFile>({
   position: Joi.number(),
   collapsed: Joi.boolean(),
   collapsible: Joi.boolean(),
+  className: Joi.string(),
 });
 
 // TODO I now believe we should read all the category metadata files ahead of time: we may need this metadata to customize docs metadata
@@ -177,6 +179,9 @@ export const DefaultSidebarItemsGenerator: SidebarItemsGenerator = async ({
       ...(doc.frontMatter.sidebar_label && {
         label: doc.frontMatter.sidebar_label,
       }),
+      ...(doc.frontMatter.sidebar_class_name && {
+        className: doc.frontMatter.sidebar_class_name,
+      }),
       ...(typeof doc.sidebarPosition !== 'undefined' && {
         position: doc.sidebarPosition,
       }),
@@ -205,6 +210,7 @@ export const DefaultSidebarItemsGenerator: SidebarItemsGenerator = async ({
     const collapsible =
       categoryMetadatas?.collapsible ?? options.sidebarCollapsible;
     const collapsed = categoryMetadatas?.collapsed ?? options.sidebarCollapsed;
+    const className = categoryMetadatas?.className;
 
     return {
       type: 'category',
@@ -213,6 +219,7 @@ export const DefaultSidebarItemsGenerator: SidebarItemsGenerator = async ({
       collapsed,
       collapsible,
       ...(typeof position !== 'undefined' && {position}),
+      ...(typeof className !== 'undefined' && {className}),
     };
   }
 
@@ -311,5 +318,5 @@ function sortSidebarItems(
     ['asc'],
   );
 
-  return sortedSidebarItems.map(({position: _removed, ...item}) => item);
+  return sortedSidebarItems.map(({position, ...item}) => item);
 }

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

@@ -40,6 +40,7 @@ type SidebarItemCategoryJSON = SidebarItemBase & {
   items: SidebarItemJSON[];
   collapsed?: boolean;
   collapsible?: boolean;
+  className?: string;
 };
 
 type SidebarItemAutogeneratedJSON = SidebarItemBase & {
@@ -100,8 +101,7 @@ function assertItem<K extends string>(
   keys: K[],
 ): asserts item is Record<K, unknown> {
   const unknownKeys = Object.keys(item).filter(
-    // @ts-expect-error: key is always string
+    (key) => !keys.includes(key as K) && key !== 'type',
-    (key) => !keys.includes(key as string) && key !== 'type',
   );
 
   if (unknownKeys.length) {
@@ -121,6 +121,7 @@ function assertIsCategory(
     'label',
     'collapsed',
     'collapsible',
+    'className',
     'customProps',
   ]);
   if (typeof item.label !== 'string') {
@@ -150,6 +151,14 @@ function assertIsCategory(
       `Error loading ${JSON.stringify(item)}: "collapsible" must be a boolean.`,
     );
   }
+  if (
+    typeof item.className !== 'undefined' &&
+    typeof item.className !== 'string'
+  ) {
+    throw new Error(
+      `Error loading ${JSON.stringify(item)}: "className" must be a string.`,
+    );
+  }
 }
 
 function assertIsAutogenerated(
@@ -173,24 +182,33 @@ function assertIsAutogenerated(
 function assertIsDoc(
   item: Record<string, unknown>,
 ): asserts item is SidebarItemDoc {
-  assertItem(item, ['id', 'label', 'customProps']);
+  assertItem(item, ['id', 'label', 'className', 'customProps']);
   if (typeof item.id !== 'string') {
     throw new Error(
       `Error loading ${JSON.stringify(item)}: "id" must be a string.`,
     );
   }
 
-  if (item.label && typeof item.label !== 'string') {
+  if (typeof item.label !== 'undefined' && typeof item.label !== 'string') {
     throw new Error(
       `Error loading ${JSON.stringify(item)}: "label" must be a string.`,
     );
   }
+
+  if (
+    typeof item.className !== 'undefined' &&
+    typeof item.className !== 'string'
+  ) {
+    throw new Error(
+      `Error loading ${JSON.stringify(item)}: "className" must be a string.`,
+    );
+  }
 }
 
 function assertIsLink(
   item: Record<string, unknown>,
 ): asserts item is SidebarItemLink {
-  assertItem(item, ['href', 'label', 'customProps']);
+  assertItem(item, ['href', 'label', 'className', 'customProps']);
   if (typeof item.href !== 'string') {
     throw new Error(
       `Error loading ${JSON.stringify(item)}: "href" must be a string.`,
@@ -201,6 +219,14 @@ function assertIsLink(
       `Error loading ${JSON.stringify(item)}: "label" must be a string.`,
     );
   }
+  if (
+    typeof item.className !== 'undefined' &&
+    typeof item.className !== 'string'
+  ) {
+    throw new Error(
+      `Error loading ${JSON.stringify(item)}: "className" must be a string.`,
+    );
+  }
 }
 
 /**

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

@@ -105,6 +105,7 @@ export type PluginOptions = MetadataOptions &
   };
 
 export type SidebarItemBase = {
+  className?: string;
   customProps?: Record<string, unknown>;
 };
 
@@ -217,6 +218,7 @@ export type DocFrontMatter = {
   slug?: string;
   sidebar_label?: string;
   sidebar_position?: number;
+  sidebar_class_name?: string;
   pagination_label?: string;
   custom_edit_url?: string | null;
   parse_number_prefixes?: boolean;

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

@@ -80,7 +80,7 @@ function DocSidebarDesktop({path, sidebar, onCollapse, isHidden}: Props) {
             !isAnnouncementBarClosed && showAnnouncementBar,
         })}>
         <ul className={clsx(ThemeClassNames.docs.docSidebarMenu, 'menu__list')}>
-          <DocSidebarItems items={sidebar} activePath={path} />
+          <DocSidebarItems items={sidebar} activePath={path} level={1} />
         </ul>
       </nav>
       {hideableSidebar && <HideableSidebarButton onClick={onCollapse} />}
@@ -99,6 +99,7 @@ const DocSidebarMobileSecondaryMenu: MobileSecondaryMenuComponent<Props> = ({
         items={sidebar}
         activePath={path}
         onItemClick={() => toggleSidebar()}
+        level={1}
       />
     </ul>
   );

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

@@ -100,9 +100,10 @@ function DocSidebarItemCategory({
   item,
   onItemClick,
   activePath,
+  level,
   ...props
 }: Props & {item: PropSidebarItemCategory}) {
-  const {items, label, collapsible} = item;
+  const {items, label, collapsible, className} = item;
 
   const isActive = isActiveSidebarItem(item, activePath);
 
@@ -123,10 +124,12 @@ function DocSidebarItemCategory({
     <li
       className={clsx(
         ThemeClassNames.docs.docSidebarItemCategory,
+        ThemeClassNames.docs.docSidebarItemCategoryLevel(level),
         'menu__list-item',
         {
           'menu__list-item--collapsed': collapsed,
         },
+        className,
       )}>
       {/* eslint-disable-next-line jsx-a11y/anchor-is-valid */}
       <a
@@ -154,6 +157,7 @@ function DocSidebarItemCategory({
           tabIndex={collapsed ? -1 : 0}
           onItemClick={onItemClick}
           activePath={activePath}
+          level={level + 1}
         />
       </Collapsible>
     </li>
@@ -164,15 +168,18 @@ function DocSidebarItemLink({
   item,
   onItemClick,
   activePath,
+  level,
   ...props
 }: Props & {item: PropSidebarItemLink}) {
-  const {href, label} = item;
+  const {href, label, className} = item;
   const isActive = isActiveSidebarItem(item, activePath);
   return (
     <li
       className={clsx(
         ThemeClassNames.docs.docSidebarItemLink,
+        ThemeClassNames.docs.docSidebarItemLinkLevel(level),
         'menu__list-item',
+        className,
       )}
       key={label}>
       <Link

packages/docusaurus-theme-classic/src/types.d.ts

@@ -140,6 +140,7 @@ declare module '@theme/DocSidebarItem' {
   type DocSidebarPropsBase = {
     readonly activePath: string;
     readonly onItemClick?: () => void;
+    readonly level: number;
     readonly tabIndex?: number;
   };
 

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

@@ -50,9 +50,13 @@ export const ThemeClassNames = {
     docSidebarMenu: 'theme-doc-sidebar-menu',
     docSidebarItemCategory: 'theme-doc-sidebar-item-category',
     docSidebarItemLink: 'theme-doc-sidebar-item-link',
+    docSidebarItemCategoryLevel: (level: number) =>
+      `theme-doc-sidebar-item-category-level-${level}` as const,
+    docSidebarItemLinkLevel: (level: number) =>
+      `theme-doc-sidebar-item-link-level-${level}` as const,
     // TODO add other stable classNames here
   },
   blog: {
     // TODO add other stable classNames here
   },
-};
+} as const;

website/_dogfooding/docs-tests-sidebars.js

@@ -10,6 +10,7 @@ module.exports = {
     {
       type: 'doc',
       id: 'index',
+      className: 'red',
       label: 'Index',
     },
     {
@@ -23,9 +24,16 @@ module.exports = {
       label: 'Huge sidebar category',
       items: generateHugeSidebarItems(4),
     },
+    {
+      type: 'link',
+      label: 'External link',
+      href: 'https://github.com/facebook/docusaurus',
+      className: 'red',
+    },
     {
       type: 'category',
       label: 'TOC tests',
+      className: 'red',
       items: [
         {
           type: 'autogenerated',

website/docs/api/plugins/plugin-content-docs.md

@@ -247,6 +247,7 @@ Accepted fields:
 | `pagination_label` | `string` | `sidebar_label` or `title` | The text used in the document next/previous buttons for this document. |
 | `sidebar_label` | `string` | `title` | The text shown in the document sidebar for this document. |
 | `sidebar_position` | `number` | Default ordering | Controls the position of a doc inside the generated sidebar slice when using `autogenerated` sidebar items. See also [Autogenerated sidebar metadatas](/docs/sidebar#autogenerated-sidebar-metadatas). |
+| `sidebar_class_name` | `string` | `undefined` | Gives the corresponding sidebar label a special class name when using autogenerated sidebars. |
 | `hide_title` | `boolean` | `false` | Whether to hide the title at the top of the doc. It only hides a title declared through the frontmatter, and have no effect on a Markdown title at the top of your document. |
 | `hide_table_of_contents` | `boolean` | `false` | Whether to hide the table of contents to the right. |
 | `toc_min_heading_level` | `number` | `2` | The minimum heading level shown in the table of contents. Must be between 2 and 6 and lower or equal to the max value. |

website/docs/guides/docs/sidebar.md

@@ -173,6 +173,7 @@ type SidebarItemDoc =
       type: 'doc';
       id: string;
       label: string; // Sidebar label text
+      className?: string; // Class name for sidebar label
     }
 
   // Shorthand syntax
@@ -244,6 +245,7 @@ type SidebarItemLink = {
   type: 'link';
   label: string;
   href: string;
+  className?: string;
 };
 ```
 
@@ -282,6 +284,7 @@ type SidebarItemCategory = {
   type: 'category';
   label: string; // Sidebar label text.
   items: SidebarItem[]; // Array of sidebar items.
+  className?: string;
 
   // Category options:
   collapsible: boolean; // Set the category to be collapsible
@@ -519,7 +522,8 @@ This is the easy tutorial!
 ```json title="docs/tutorials/_category_.json"
 {
   "label": "Tutorial",
-  "position": 3
+  "position": 3,
+  "className": "red"
 }
 ```
 

website/src/css/custom.css

@@ -146,3 +146,7 @@ div[class^='announcementBar_'] {
   );
   font-weight: bold;
 }
+
+.red > a {
+  color: red;
+}