feat: placeholder blocks for failed import blocks

src/generic/block-type-utils/index.scss

@@ -198,3 +198,28 @@
     }
   }
 }
+
+.component-style-import-placeholder {
+  background-color: #AB0E01;
+
+  .pgn__icon:not(.btn-icon-before) {
+    color: white;
+  }
+
+  .btn-icon {
+    &:hover, &:active, &:focus {
+      background-color: darken(#AB0E01, 15%);
+    }
+  }
+
+  .btn {
+    background-color: lighten(#AB0E01, 10%);
+    border: 0;
+
+    &:hover, &:active, &:focus {
+      background-color: lighten(#AB0E01, 20%);
+      border: 1px solid var(--pgn-color-primary-base);
+      margin: -1px;
+    }
+  }
+}

src/library-authoring/LibraryContent.test.tsx

@@ -8,11 +8,14 @@ import {
   initializeMocks,
 } from '@src/testUtils';
 
+import MockAdapter from 'axios-mock-adapter/types';
+import { useGetContentHits } from '@src/search-manager';
 import { mockContentLibrary } from './data/api.mocks';
 import mockEmptyResult from '../search-modal/__mocks__/empty-search-result.json';
 import { LibraryProvider } from './common/context/LibraryContext';
 import LibraryContent from './LibraryContent';
 import { libraryComponentsMock } from './__mocks__';
+import { getModulestoreMigratedBlocksInfoUrl } from './data/api';
 
 const searchEndpoint = 'http://mock.meilisearch.local/multi-search';
 
@@ -43,9 +46,10 @@ const returnEmptyResult = (_url: string, req) => {
   return mockEmptyResult;
 };
 
-jest.mock('../search-manager', () => ({
+jest.mock('@src/search-manager', () => ({
   ...jest.requireActual('../search-manager'),
   useSearchContext: () => mockUseSearchContext(),
+  useGetContentHits: jest.fn().mockReturnValue({ isPending: true, data: null }),
 }));
 
 const withLibraryId = (libraryId: string) => ({
@@ -55,10 +59,12 @@ const withLibraryId = (libraryId: string) => ({
     </LibraryProvider>
   ),
 });
+let axiosMock: MockAdapter;
 
 describe('<LibraryHome />', () => {
   beforeEach(() => {
-    const { axiosMock } = initializeMocks();
+    const mocks = initializeMocks();
+    axiosMock = mocks.axiosMock;
 
     fetchMock.post(searchEndpoint, returnEmptyResult, { overwriteRoutes: true });
 
@@ -108,4 +114,48 @@ describe('<LibraryHome />', () => {
     fireEvent.scroll(window, { target: { scrollY: 1000 } });
     expect(mockFetchNextPage).toHaveBeenCalled();
   });
+
+  it('should show placeholderBlocks', async () => {
+    axiosMock.onGet(getModulestoreMigratedBlocksInfoUrl()).reply(200, [
+      {
+        sourceKey: 'block-v1:UNIX+UX2+2025_T2+type@library_content+block@test_lib_content',
+        targetKey: null,
+        unsupportedReason: 'The "library_content" XBlock (ID: "test_lib_content") has children, so it not supported in content libraries. It has 2 children blocks.',
+      },
+      {
+        sourceKey: 'block-v1:UNIX+UX2+2025_T2+type@conditional+block@test_conditional',
+        targetKey: null,
+        unsupportedReason: 'The "conditional" XBlock (ID: "test_conditional") has children, so it not supported in content libraries. It has 2 children blocks.',
+      },
+    ]);
+    (useGetContentHits as jest.Mock).mockReturnValue({
+      isPending: false,
+      data: {
+        hits: [
+          {
+            display_name: 'Randomized Content Block',
+            usage_key: 'block-v1:UNIX+UX2+2025_T2+type@library_content+block@test_lib_content',
+            block_type: 'library_content',
+          },
+          {
+            display_name: 'Conditional',
+            usage_key: 'block-v1:UNIX+UX2+2025_T2+type@conditional+block@test_conditional',
+            block_type: 'conditional',
+          },
+        ],
+        query: '',
+        processingTimeMs: 0,
+        limit: 2,
+        offset: 0,
+        estimatedTotalHits: 2,
+      },
+    });
+    mockUseSearchContext.mockReturnValue({
+      ...data,
+      hits: libraryComponentsMock,
+    });
+    render(<LibraryContent />, withLibraryId(mockContentLibrary.libraryId));
+    expect(await screen.findByText('Randomized Content Block')).toBeInTheDocument();
+    expect(await screen.findByText('Conditional')).toBeInTheDocument();
+  });
 });

src/library-authoring/LibraryContent.tsx

@@ -1,15 +1,17 @@
 import { useEffect } from 'react';
-import { LoadingSpinner } from '../generic/Loading';
-import { useSearchContext } from '../search-manager';
+import { LoadingSpinner } from '@src/generic/Loading';
+import { useGetContentHits, useSearchContext } from '@src/search-manager';
+import { useLoadOnScroll } from '@src/hooks';
 import { NoComponents, NoSearchResults } from './EmptyStates';
 import { useLibraryContext } from './common/context/LibraryContext';
 import { useSidebarContext } from './common/context/SidebarContext';
 import CollectionCard from './components/CollectionCard';
 import ComponentCard from './components/ComponentCard';
-import { ContentType } from './routes';
-import { useLoadOnScroll } from '../hooks';
+import { ContentType, useLibraryRoutes } from './routes';
 import messages from './collections/messages';
 import ContainerCard from './containers/ContainerCard';
+import { useMigrationBlocksInfo } from './data/apiHooks';
+import PlaceholderCard from './import-course/PlaceholderCard';
 
 /**
  * Library Content to show content grid
@@ -40,8 +42,32 @@ const LibraryContent = ({ contentType = ContentType.home }: LibraryContentProps)
     isFiltered,
     usageKey,
   } = useSearchContext();
-  const { openCreateCollectionModal } = useLibraryContext();
+  const { libraryId, openCreateCollectionModal, collectionId } = useLibraryContext();
   const { openAddContentSidebar, openComponentInfoSidebar } = useSidebarContext();
+  const { insideCollection } = useLibraryRoutes();
+  /**
+  * Placeholder blocks represent fake blocks for failed imports from other sources, such as courses.
+  * They should only be displayed when viewing all components in the home tab of the library and the
+    collection representing the course.
+  * Blocks should be hidden when the user is searching or filtering them.
+  */
+  const showPlaceholderBlocks = ([ContentType.home].includes(contentType) || insideCollection) && !isFiltered;
+  const { data: placeholderBlocks } = useMigrationBlocksInfo(
+    libraryId,
+    collectionId,
+    true,
+    showPlaceholderBlocks,
+  );
+  // Fetch unsupported blocks usage_key information from meilisearch index.
+  const { data: placeholderData } = useGetContentHits(
+    [
+      `usage_key IN [${placeholderBlocks?.map((block) => `"${block.sourceKey}"`).join(',')}]`,
+    ],
+    (placeholderBlocks?.length || 0) > 0,
+    ['usage_key', 'block_type', 'display_name'],
+    placeholderBlocks?.length,
+    true,
+  );
 
   useEffect(() => {
     if (usageKey) {
@@ -81,6 +107,12 @@ const LibraryContent = ({ contentType = ContentType.home }: LibraryContentProps)
 
         return <CardComponent key={contentHit.id} hit={contentHit} />;
       })}
+      {showPlaceholderBlocks && placeholderData?.hits?.map((item) => (
+        <PlaceholderCard
+          displayName={item.display_name}
+          blockType={item.block_type}
+        />
+      ))}
     </div>
   );
 };

src/library-authoring/components/BaseCard.tsx

@@ -12,6 +12,7 @@ import ComponentCount from '@src/generic/component-count';
 import TagCount from '@src/generic/tag-count';
 import { BlockTypeLabel, type ContentHitTags, Highlight } from '@src/search-manager';
 import { skipIfUnwantedTarget } from '@src/utils';
+import { Report } from '@openedx/paragon/icons';
 import messages from './messages';
 
 type BaseCardProps = {
@@ -25,6 +26,7 @@ type BaseCardProps = {
   hasUnpublishedChanges?: boolean;
   onSelect: (e?: React.MouseEvent) => void;
   selected?: boolean;
+  isPlaceholder?: boolean;
 };
 
 const BaseCard = ({
@@ -48,6 +50,7 @@ const BaseCard = ({
 
   const itemIcon = getItemIcon(itemType);
   const intl = useIntl();
+  const itemComponentStyle = !props.isPlaceholder ? getComponentStyleColor(itemType) : 'component-style-import-placeholder';
 
   return (
     <Container className="library-item-card selected">
@@ -62,9 +65,9 @@ const BaseCard = ({
         className={selected ? 'selected' : undefined}
       >
         <Card.Header
-          className={`library-item-header ${getComponentStyleColor(itemType)}`}
+          className={`library-item-header ${itemComponentStyle}`}
           title={
-            <Icon src={itemIcon} className="library-item-header-icon my-2" />
+            <Icon src={props.isPlaceholder ? Report : itemIcon} className="library-item-header-icon my-2" />
           }
           actions={(
             <div
@@ -91,8 +94,12 @@ const BaseCard = ({
                   <BlockTypeLabel blockType={itemType} />
                 </small>
               </Stack>
-              <ComponentCount count={numChildren} />
-              <TagCount size="sm" count={tagCount} />
+              {!props.isPlaceholder && (
+              <>
+                <ComponentCount count={numChildren} />
+                <TagCount size="sm" count={tagCount} />
+              </>
+              )}
             </Stack>
             <div className="badge-container d-flex align-items-center justify-content-center">
               {props.hasUnpublishedChanges && (

src/library-authoring/data/api.ts

@@ -157,10 +157,18 @@ export const getLibraryRestoreStatusApiUrl = (taskId: string) => `${getApiBaseUr
  * Get the URL for the API endpoint to copy a single container.
  */
 export const getLibraryContainerCopyApiUrl = (containerId: string) => `${getLibraryContainerApiUrl(containerId)}copy/`;
+/**
+ * Base url for modulestore_migrator
+ */
+export const getBaseModuleStoreMigrationUrl = () => `${getApiBaseUrl()}/api/modulestore_migrator/v1/`;
 /**
  * Get the url for the API endpoint to list library course imports.
  */
-export const getCourseImportsApiUrl = (libraryId: string) => `${getApiBaseUrl()}/api/modulestore_migrator/v1/library/${libraryId}/migrations/courses/`;
+export const getCourseImportsApiUrl = (libraryId: string) => `${getBaseModuleStoreMigrationUrl()}library/${libraryId}/migrations/courses/`;
+/**
+ * Get the url for the API endpoint to get migration blocks info.
+ */
+export const getModulestoreMigratedBlocksInfoUrl = () => `${getBaseModuleStoreMigrationUrl()}migration_blocks/`;
 
 export interface ContentLibrary {
   id: string;
@@ -830,3 +838,32 @@ export async function getMigrationInfo(sourceKeys: string[]): Promise<Record<str
   const { data } = await client.get(`${getApiBaseUrl()}/api/modulestore_migrator/v1/migration_info/`, { params });
   return camelCaseObject(data);
 }
+
+export interface BlockMigrationInfo {
+  sourceKey: string;
+  targetKey: string | null;
+  unsupportedReason?: string;
+}
+
+/**
+ * Get the migration blocks info data for a library
+ */
+export async function getModulestoreMigrationBlocksInfo(
+  libraryId: string,
+  collectionId?: string,
+  isFailed?: boolean,
+): Promise<BlockMigrationInfo[]> {
+  const client = getAuthenticatedHttpClient();
+
+  const params = new URLSearchParams();
+  params.append('target_key', libraryId);
+  if (collectionId) {
+    params.append('target_collection_key', collectionId);
+  }
+  if (isFailed !== undefined) {
+    params.append('is_failed', JSON.stringify(isFailed));
+  }
+
+  const { data } = await client.get(getModulestoreMigratedBlocksInfoUrl(), { params });
+  return camelCaseObject(data);
+}

src/library-authoring/data/apiHooks.ts

@@ -99,6 +99,12 @@ export const libraryAuthoringQueryKeys = {
     ...libraryAuthoringQueryKeys.allMigrationInfo(),
     ...sourceKeys,
   ],
+  migrationBlocksInfo: (libraryId: string, collectionId?: string, isFailed?: boolean) => [
+    ...libraryAuthoringQueryKeys.allMigrationInfo(),
+    libraryId,
+    collectionId,
+    isFailed,
+  ],
 };
 
 export const xblockQueryKeys = {
@@ -981,3 +987,18 @@ export const useMigrationInfo = (sourcesKeys: string[], enabled: boolean = true)
     queryFn: enabled ? () => api.getMigrationInfo(sourcesKeys) : skipToken,
   })
 );
+
+/**
+ * Returns the migration blocks info of a given library
+ */
+export const useMigrationBlocksInfo = (
+  libraryId: string,
+  collectionId?: string,
+  isFailed?: boolean,
+  enabled = true,
+) => (
+  useQuery({
+    queryKey: libraryAuthoringQueryKeys.migrationBlocksInfo(libraryId, collectionId, isFailed),
+    queryFn: enabled ? () => api.getModulestoreMigrationBlocksInfo(libraryId, collectionId, isFailed) : skipToken,
+  })
+);

src/library-authoring/import-course/PlaceholderCard.tsx

@@ -0,0 +1,28 @@
+import BaseCard from '../components/BaseCard';
+
+interface PlaceHolderCardProps {
+  blockType: string;
+  displayName: string;
+  description?: string;
+}
+
+const PlaceholderCard = ({ blockType, displayName, description }: PlaceHolderCardProps) => {
+  const truncatedDescription = description ? `${description.substring(0, 40) }...` : undefined;
+  /* istanbul ignore next */
+  return (
+    <BaseCard
+      itemType={blockType}
+      displayName={displayName}
+      description={truncatedDescription}
+      tags={{}}
+      numChildren={0}
+      actions={null}
+      hasUnpublishedChanges={false}
+      onSelect={() => null}
+      selected={false}
+      isPlaceholder
+    />
+  );
+};
+
+export default PlaceholderCard;