show empty label in TableOfContents.jsx

resource/locales/en_US/translation.json

@@ -99,7 +99,6 @@
   "Input page name (optional)": "Input page name (optional)",
   "New Page": "New page",
   "Create under": "Create page under below:",
-  "Table of Contents": "Table of Contents",
   "Wiki Management Home Page": "Wiki Management Home Page",
   "App Settings": "App Settings",
   "Site URL settings": "Site URL settings",
@@ -295,6 +294,9 @@
       "no_deadline":"This page has no expiration date"
     }
   },
+  "page_table_of_contents": {
+    "empty": "Table of Contents is empty"
+  },
   "page_edit": {
     "Show active line": "Show active line",
     "overwrite_scopes": "{{operation}} and Overwrite scopes of all descendants",

resource/locales/ja_JP/translation.json

@@ -100,7 +100,6 @@
   "Input page name (optional)": "ページ名を入力(空欄OK)",
   "New Page": "新規ページ",
   "Create under": "ページを以下に作成",
-  "Table of Contents": "目次",
   "Wiki Management Home Page": "Wiki管理トップ",
   "App Settings": "アプリ設定",
   "Site URL settings": "サイトURL設定",
@@ -297,6 +296,9 @@
       "no_deadline": "このページに有効期限は設定されていません。"
     }
   },
+  "page_table_of_contents": {
+    "empty": "目次は空です"
+  },
   "page_edit": {
     "Show active line": "アクティブ行をハイライト",
     "overwrite_scopes": "{{operation}}と同時に全ての配下ページのスコープを上書き",

resource/locales/zh_CN/translation.json

@@ -108,7 +108,6 @@
 	"Input page name (optional)": "Input page name (optional)",
 	"New Page": "新页面",
 	"Create under": "Create page under below:",
-	"Table of Contents": "Table of Contents",
 	"Wiki Management Home Page": "Wiki管理首页",
 	"App Settings": "系统设置",
 	"Site URL settings": "主页URL设置",
@@ -282,7 +281,10 @@
 		"notice": {
 			"conflict": "无法保存您所做的更改，因为其他人正在编辑此页。请在重新加载页面后重新编辑受影响的部分。"
 		}
-	},
+  },
+  "page_table_of_contents": {
+    "empty": "目录为空"
+  },
   "page_comment": {
     "display_the_page_when_posting_this_comment": "Display the page when posting this comment"
   },

src/client/js/components/TableOfContents.jsx

@@ -20,7 +20,7 @@ const logger = loggerFactory('growi:TableOfContents');
  */
 const TableOfContents = (props) => {
 
-  const { pageContainer, navigationContainer } = props;
+  const { t, pageContainer, navigationContainer } = props;
   const { pageUser } = pageContainer.state;
   const isUserPage = pageUser != null;
 
@@ -59,14 +59,24 @@ const TableOfContents = (props) => {
       stickyElemSelector=".grw-side-contents-sticky-container"
       calcViewHeightFunc={calcViewHeight}
     >
-      <div
-        id="revision-toc-content"
-        className="revision-toc-content mb-3"
-        // eslint-disable-next-line react/no-danger
-        dangerouslySetInnerHTML={{
-        __html: tocHtml,
-      }}
-      />
+      { tocHtml !== ''
+      ? (
+        <div
+          id="revision-toc-content"
+          className="revision-toc-content mb-3"
+          // eslint-disable-next-line react/no-danger
+          dangerouslySetInnerHTML={{ __html: tocHtml }}
+        />
+      )
+      : (
+        <div
+          id="revision-toc-content"
+          className="revision-toc-content mb-2"
+        >
+          <span className="text-muted">({t('page_table_of_contents.empty')})</span>
+        </div>
+      ) }
+
     </StickyStretchableScroller>
   );
 
@@ -78,6 +88,8 @@ const TableOfContents = (props) => {
 const TableOfContentsWrapper = withUnstatedContainers(TableOfContents, [PageContainer, NavigationContainer]);
 
 TableOfContents.propTypes = {
+  t: PropTypes.func.isRequired, // i18next
+
   pageContainer: PropTypes.instanceOf(PageContainer).isRequired,
   navigationContainer: PropTypes.instanceOf(NavigationContainer).isRequired,
 };