feat(v2): support external links & linking to docs from other sidebars

v2/lib/load/docs/order.js

@@ -1,52 +1,66 @@
 // build the docs meta such as next, previous, category and sidebar
+
 module.exports = function createOrder(allSidebars = {}) {
   const order = {};
-  if (!allSidebars) {
-    return order;
-  }
-  Object.keys(allSidebars).forEach(sidebar => {
-    const categories = allSidebars[sidebar];
 
-    let ids = [];
+  Object.keys(allSidebars).forEach(sidebarId => {
+    const sidebar = allSidebars[sidebarId];
+
+    const ids = [];
     const categoryOrder = [];
     const subCategoryOrder = [];
-    Object.keys(categories).forEach(category => {
-      if (Array.isArray(categories[category])) {
-        ids = ids.concat(categories[category]);
-
-        // eslint-disable-next-line
-        for (let i = 0; i < categories[category].length; i++) {
-          categoryOrder.push(category);
-          subCategoryOrder.push(undefined);
+    const indexItems = ({items, categoryLabel, subCategoryLabel}) => {
+      items.forEach(item => {
+        switch (item.type) {
+          case 'category':
+            indexItems({
+              items: item.items,
+              categoryLabel: categoryLabel || item.label,
+              subCategoryLabel: categoryLabel && item.label,
+            });
+            break;
+          case 'ref':
+          case 'link':
+            // refs and links should not be shown in navigation
+            break;
+          case 'doc':
+            ids.push(item.id);
+            categoryOrder.push(categoryLabel);
+            subCategoryOrder.push(subCategoryLabel);
+            break;
+          default:
+            throw new Error(
+              `Unknown item type: ${item.type}. Item: ${JSON.stringify(item)}`,
+            );
         }
-      } else {
-        Object.keys(categories[category]).forEach(subCategory => {
-          ids = ids.concat(categories[category][subCategory]);
-
-          // eslint-disable-next-line
-          for (let i = 0; i < categories[category][subCategory].length; i++) {
-            categoryOrder.push(category);
-            subCategoryOrder.push(subCategory);
-          }
-        });
-      }
-    });
+      });
+    };
+
+    indexItems({items: sidebar});
 
     // eslint-disable-next-line
     for (let i = 0; i < ids.length; i++) {
       const id = ids[i];
       let previous;
       let next;
-      if (i > 0) previous = ids[i - 1];
-      if (i < ids.length - 1) next = ids[i + 1];
+
+      if (i > 0) {
+        previous = ids[i - 1];
+      }
+
+      if (i < ids.length - 1) {
+        next = ids[i + 1];
+      }
+
       order[id] = {
         previous,
         next,
-        sidebar,
+        sidebar: sidebarId,
         category: categoryOrder[i],
         subCategory: subCategoryOrder[i],
       };
     }
   });
+
   return order;
 };

v2/lib/load/docs/sidebars.js

@@ -2,6 +2,110 @@ const fs = require('fs-extra');
 const path = require('path');
 const {idx} = require('../utils');
 
+/**
+ * Check that item contains only allowed keys
+ *
+ * @param {Object} item
+ * @param {Array<string>} keys
+ */
+function assertItem(item, keys) {
+  const unknownKeys = Object.keys(item).filter(
+    key => !keys.includes(key) && key !== 'type',
+  );
+
+  if (unknownKeys.length) {
+    throw new Error(
+      `Unknown sidebar item keys: ${unknownKeys}. Item: ${JSON.stringify(
+        item,
+      )}`,
+    );
+  }
+}
+
+/**
+ * Normalizes recursively category and all its children. Ensures, that at the end
+ * each item will be an object with the corresponding type
+ *
+ * @param {Array<Object>} category
+ * @param {number} [level=0]
+ *
+ * @return {Array<Object>}
+ */
+function normalizeCategory(category, level = 0) {
+  if (level === 2) {
+    throw new Error(
+      `Can not process ${
+        category.label
+      } category. Categories can be nested only one level deep.`,
+    );
+  }
+
+  assertItem(category, ['items', 'label']);
+
+  if (!Array.isArray(category.items)) {
+    throw new Error(
+      `Error loading ${category.label} category. Category items must be array.`,
+    );
+  }
+
+  const items = category.items.map(item => {
+    switch (item.type) {
+      case 'category':
+        return normalizeCategory(item, level + 1);
+      case 'link':
+        assertItem(item, ['href', 'label']);
+        break;
+      case 'ref':
+        assertItem(item, ['id', 'label']);
+        break;
+      default:
+        if (typeof item === 'string') {
+          return {
+            type: 'doc',
+            id: item,
+          };
+        }
+
+        if (item.type !== 'doc') {
+          throw new Error(`Unknown sidebar item type: ${item.type}`);
+        }
+
+        assertItem(item, ['id', 'label']);
+        break;
+    }
+
+    return item;
+  });
+
+  return {...category, items};
+}
+
+/**
+ * Converts sidebars object to mapping to arrays of sidebar item objects
+ *
+ * @param  {{[key: string]: Object}} sidebars
+ *
+ * @return {{[key: string]: Array<Object>}}
+ */
+function normalizeSidebar(sidebars) {
+  return Object.entries(sidebars).reduce((acc, [sidebarId, sidebar]) => {
+    let normalizedSidebar = sidebar;
+
+    if (!Array.isArray(sidebar)) {
+      // convert sidebar to a more generic structure
+      normalizedSidebar = Object.entries(sidebar).map(([label, items]) => ({
+        type: 'category',
+        label,
+        items,
+      }));
+    }
+
+    acc[sidebarId] = normalizedSidebar.map(item => normalizeCategory(item));
+
+    return acc;
+  }, {});
+}
+
 module.exports = function loadSidebars({siteDir, env}, deleteCache = true) {
   let allSidebars = {};
 
@@ -34,5 +138,6 @@ module.exports = function loadSidebars({siteDir, env}, deleteCache = true) {
       });
     }
   }
-  return allSidebars;
+
+  return normalizeSidebar(allSidebars);
 };

v2/lib/theme/Sidebar/SidebarCategory.js

@@ -0,0 +1,32 @@
+import React from 'react';
+import classnames from 'classnames';
+
+import styles from './styles.css';
+
+export default function SidebarCategory({
+  label,
+  items,
+  subCategory,
+  renderItem,
+}) {
+  const Heading = subCategory ? 'h4' : 'h3';
+
+  return (
+    <div
+      className={classnames(styles.sidebarGroup, {
+        [styles.sidebarSubGroup]: subCategory,
+      })}
+      key={label}>
+      <Heading
+        className={classnames(
+          styles.sidebarItem,
+          styles.sidebarGroupTitle,
+          styles.sidebarGroupCategoryTitle,
+        )}>
+        {label}
+      </Heading>
+
+      <ul className={styles.sidebarList}>{items.map(renderItem)}</ul>
+    </div>
+  );
+}

v2/lib/theme/Sidebar/SidebarLink.js

@@ -0,0 +1,24 @@
+import React from 'react';
+import {NavLink} from 'react-router-dom';
+import classnames from 'classnames';
+
+import styles from './styles.css';
+
+export default function SidebarLink({href, label}) {
+  const isExternal = /^(https?:|\/\/)/.test(href);
+  const Link = isExternal
+    ? // eslint-disable-next-line jsx-a11y/anchor-has-content
+      ({to, activeClassName, ...linkProps}) => <a {...linkProps} href={to} />
+    : NavLink;
+
+  return (
+    <li className={styles.sidebarListItem}>
+      <Link
+        activeClassName={styles.sidebarLinkActive}
+        className={classnames(styles.sidebarLink, styles.sidebarItem)}
+        to={href}>
+        {label}
+      </Link>
+    </li>
+  );
+}

v2/lib/theme/Sidebar/index.js

@@ -1,80 +1,63 @@
 import React from 'react';
-import {NavLink} from 'react-router-dom';
-
-import classnames from 'classnames';
 
+import SidebarLink from './SidebarLink';
+import SidebarCategory from './SidebarCategory';
 import styles from './styles.css';
 
 function Sidebar(props) {
   const {metadata, docsSidebars, docsMetadatas} = props;
   const {sidebar, language} = metadata;
-  if (!sidebar || !docsSidebars) {
+
+  if (!sidebar) {
     return null;
   }
+
   const thisSidebar = docsSidebars[sidebar];
 
-  const renderItemLink = rawLinkID => {
-    const linkID = (language ? `${language}-` : '') + rawLinkID;
+  if (!thisSidebar) {
+    throw new Error(`Can not find ${sidebar} config`);
+  }
+
+  const convertDocLink = item => {
+    const linkID = (language ? `${language}-` : '') + item.id;
     const linkMetadata = docsMetadatas[linkID];
+
     if (!linkMetadata) {
       throw new Error(
         `Improper sidebars.json file, document with id '${linkID}' not found.`,
       );
     }
 
-    return (
-      <li className={styles.sidebarListItem} key={linkID}>
-        <NavLink
-          activeClassName={styles.sidebarLinkActive}
-          className={classnames(styles.sidebarLink, styles.sidebarItem)}
-          to={linkMetadata.permalink}>
-          {linkMetadata.sidebar_label || linkMetadata.title}
-        </NavLink>
-      </li>
-    );
+    return {
+      type: 'link',
+      label: linkMetadata.sidebar_label || linkMetadata.title,
+      href: linkMetadata.permalink,
+    };
   };
 
-  const renderCategory = categoryName => {
-    const category = thisSidebar[categoryName];
-    return (
-      <div className={styles.sidebarGroup} key={categoryName}>
-        <h3
-          className={classnames(
-            styles.sidebarItem,
-            styles.sidebarGroupTitle,
-            styles.sidebarGroupCategoryTitle,
-          )}>
-          {categoryName}
-        </h3>
-        <ul className={styles.sidebarList}>
-          {Array.isArray(category)
-            ? category.map(renderItemLink)
-            : Object.keys(category).map(subCategoryName => (
-                <div className={styles.sidebarSubGroup} key={subCategoryName}>
-                  <h4
-                    className={classnames(
-                      styles.sidebarItem,
-                      styles.sidebarGroupTitle,
-                      styles.sidebarGroupSubcategorytitle,
-                    )}>
-                    {subCategoryName}
-                  </h4>
-                  <ul className={styles.sidebarList}>
-                    {category[subCategoryName].map(renderItemLink)}
-                  </ul>
-                </div>
-              ))}
-        </ul>
-      </div>
-    );
+  const renderItem = (item, {root} = {}) => {
+    switch (item.type) {
+      case 'category':
+        return (
+          <SidebarCategory
+            {...item}
+            key={item.label}
+            subCategory={!root}
+            renderItem={renderItem}
+          />
+        );
+      case 'link':
+        return <SidebarLink {...item} key={item.href} />;
+      case 'ref':
+      default:
+        return renderItem(convertDocLink(item));
+    }
   };
 
   return (
-    thisSidebar && (
-      <div className={styles.sidebar}>
-        {Object.keys(thisSidebar).map(renderCategory)}
-      </div>
-    )
+    <div className={styles.sidebar}>
+      {thisSidebar.map(item => renderItem(item, {root: true}))}
+    </div>
   );
 }