⚡️(frontend) fix heading insertion via useHeadingAccessibilityFilter

enforces contiguous heading levels to ensure accessibility compliance

Signed-off-by: Cyril <[email protected]>

src/frontend/apps/impress/src/features/docs/doc-editor/components/BlockNoteSuggestionMenu.tsx

@@ -9,6 +9,7 @@ import {
 import React, { useMemo } from 'react';
 import { useTranslation } from 'react-i18next';
 
+import { useHeadingAccessibilityFilter } from '../hook';
 import {
   DocsBlockSchema,
   DocsInlineContentSchema,
@@ -34,6 +35,7 @@ export const BlockNoteSuggestionMenu = () => {
   const { t } = useTranslation();
   const basicBlocksName = useDictionary().slash_menu.page_break.group;
   const getInterlinkingMenuItems = useGetInterlinkingMenuItems();
+  const { filterHeadingItemsByAccessibility } = useHeadingAccessibilityFilter();
 
   const getSlashMenuItems = useMemo(() => {
     // We insert it after the "Code Block" item to have the interlinking block displayed after the basic blocks
@@ -47,11 +49,16 @@ export const BlockNoteSuggestionMenu = () => {
       ...defaultMenu.slice(index + 1),
     ];
 
+    const filteredMenuItems = filterHeadingItemsByAccessibility(
+      newSlashMenuItems,
+      editor,
+    );
+
     return async (query: string) =>
       Promise.resolve(
         filterSuggestionItems(
           combineByGroup(
-            newSlashMenuItems,
+            filteredMenuItems,
             getCalloutReactSlashMenuItems(editor, t, basicBlocksName),
             getMultiColumnSlashMenuItems?.(editor) || [],
             getPageBreakReactSlashMenuItems(editor),
@@ -60,7 +67,13 @@ export const BlockNoteSuggestionMenu = () => {
           query,
         ),
       );
-  }, [basicBlocksName, editor, getInterlinkingMenuItems, t]);
+  }, [
+    basicBlocksName,
+    editor,
+    getInterlinkingMenuItems,
+    t,
+    filterHeadingItemsByAccessibility,
+  ]);
 
   return (
     <SuggestionMenuController

src/frontend/apps/impress/src/features/docs/doc-editor/hook/index.ts

@@ -2,3 +2,4 @@ export * from './useHeadings';
 export * from './useSaveDoc';
 export * from './useShortcuts';
 export * from './useUploadFile';
+export * from './useHeadingAccessibilityFilter';

src/frontend/apps/impress/src/features/docs/doc-editor/hook/useHeadingAccessibilityFilter.ts

@@ -0,0 +1,87 @@
+import { getDefaultReactSlashMenuItems } from '@blocknote/react';
+
+import { DocsBlockNoteEditor } from '../types';
+
+export const useHeadingAccessibilityFilter = () => {
+  // function to extract heading level from menu item
+  const getHeadingLevel = (
+    item: ReturnType<typeof getDefaultReactSlashMenuItems>[0],
+  ): number => {
+    const title = item.title?.toLowerCase() || '';
+    const aliases = item.aliases || [];
+    const HEADING_2 = 'heading 2';
+    const HEADING_3 = 'heading 3';
+    const TITLE_2 = 'titre 2';
+    const TITLE_3 = 'titre 3';
+
+    if (
+      title.includes(HEADING_2) ||
+      title.includes(TITLE_2) ||
+      aliases.some(
+        (alias: string) => alias.includes(HEADING_2) || alias.includes(TITLE_2),
+      )
+    ) {
+      return 2;
+    }
+
+    if (
+      title.includes(HEADING_3) ||
+      title.includes(TITLE_3) ||
+      aliases.some(
+        (alias: string) => alias.includes(HEADING_3) || alias.includes(TITLE_3),
+      )
+    ) {
+      return 3;
+    }
+
+    return 1;
+  };
+
+  // function to check if item is a heading
+  const isHeadingItem = (
+    item: ReturnType<typeof getDefaultReactSlashMenuItems>[0],
+  ): boolean => {
+    return item.onItemClick?.toString().includes('heading');
+  };
+
+  const filterHeadingItemsByAccessibility = (
+    items: ReturnType<typeof getDefaultReactSlashMenuItems>,
+    editor: DocsBlockNoteEditor,
+  ) => {
+    const existingLevels = editor.document
+      .filter((block) => block.type === 'heading')
+      .map((block) => (block.props as { level: number }).level);
+
+    const hasH1 = existingLevels.includes(1);
+
+    if (existingLevels.length === 0) {
+      return items.filter(
+        (item) => !isHeadingItem(item) || getHeadingLevel(item) === 1,
+      );
+    }
+
+    const maxLevel = Math.max(...existingLevels);
+    const minLevel = Math.min(...existingLevels);
+
+    return items.filter((item) => {
+      if (!isHeadingItem(item)) {
+        return true;
+      }
+
+      const headingLevel = getHeadingLevel(item);
+
+      // Never allow h1 if one already exists >> accessibility tells that we can only have one h1 per document
+      if (headingLevel === 1 && hasH1) {
+        return false;
+      }
+
+      return (
+        headingLevel === maxLevel ||
+        headingLevel === maxLevel + 1 ||
+        (headingLevel === minLevel - 1 && minLevel > 1)
+      );
+    });
+  };
+
+  return { filterHeadingItemsByAccessibility };
+};