fix(dataset): load cover image on detail page for private datasets

file-service/src/main/scala/org/apache/texera/service/resource/DatasetResource.scala

@@ -2182,4 +2182,49 @@ class DatasetResource extends LazyLogging {
       Response.temporaryRedirect(new URI(presignedUrl)).build()
     }
   }
+
+  /**
+    * Get a presigned S3 URL for the dataset cover image as JSON.
+    * JWT-aware variant of GET /{did}/cover; required for private datasets
+    * since `<img src>` cannot attach the Authorization header.
+    */
+  @GET
+  @Path("/{did}/cover-url")
+  @Produces(Array(MediaType.APPLICATION_JSON))
+  def getDatasetCoverUrl(
+      @PathParam("did") did: Integer,
+      @Auth sessionUser: Optional[SessionUser]
+  ): Response = {
+    withTransaction(context) { ctx =>
+      val dataset = getDatasetByID(ctx, did)
+
+      val requesterUid = if (sessionUser.isPresent) Some(sessionUser.get().getUid) else None
+
+      if (requesterUid.isEmpty && !dataset.getIsPublic) {
+        throw new ForbiddenException(ERR_USER_HAS_NO_ACCESS_TO_DATASET_MESSAGE)
+      } else if (requesterUid.exists(uid => !userHasReadAccess(ctx, did, uid))) {
+        throw new ForbiddenException(ERR_USER_HAS_NO_ACCESS_TO_DATASET_MESSAGE)
+      }
+
+      Option(dataset.getCoverImage) match {
+        case None =>
+          Response.ok(Map("url" -> null)).build()
+        case Some(coverImage) =>
+          val owner = getOwner(ctx, did)
+          val fullPath = s"${owner.getEmail}/${dataset.getName}/$coverImage"
+
+          val document = DocumentFactory
+            .openReadonlyDocument(FileResolver.resolve(fullPath))
+            .asInstanceOf[OnDataset]
+
+          val presignedUrl = LakeFSStorageClient.getFilePresignedUrl(
+            document.getRepositoryName(),
+            document.getVersionHash(),
+            document.getFileRelativePath()
+          )
+
+          Response.ok(Map("url" -> presignedUrl)).build()
+      }
+    }
+  }
 }

file-service/src/test/scala/org/apache/texera/service/resource/DatasetResourceSpec.scala

@@ -2531,6 +2531,50 @@ class DatasetResourceSpec
     response.getHeaderString("Location") should not be null
   }
 
+  "getDatasetCoverUrl" should "return presigned url for owner of private dataset" in {
+    testDatasetVersion
+
+    val dataset = datasetDao.fetchOneByDid(baseDataset.getDid)
+    dataset.setIsPublic(false)
+    dataset.setCoverImage(testCoverImagePath)
+    datasetDao.update(dataset)
+
+    val response = datasetResource.getDatasetCoverUrl(
+      baseDataset.getDid,
+      Optional.of(sessionUser)
+    )
+
+    response.getStatus shouldEqual 200
+    Option(entityAsScalaMap(response)("url")) shouldBe defined
+  }
+
+  it should "reject private dataset cover for users without access" in {
+    val dataset = datasetDao.fetchOneByDid(baseDataset.getDid)
+    dataset.setOwnerUid(ownerUser.getUid)
+    dataset.setIsPublic(false)
+    dataset.setCoverImage("v1/cover.jpg")
+    datasetDao.update(dataset)
+
+    assertThrows[ForbiddenException] {
+      datasetResource.getDatasetCoverUrl(baseDataset.getDid, Optional.of(sessionUser2))
+    }
+  }
+
+  it should "return null url when no cover image is set" in {
+    val dataset = datasetDao.fetchOneByDid(baseDataset.getDid)
+    dataset.setCoverImage(null)
+    dataset.setIsPublic(true)
+    datasetDao.update(dataset)
+
+    val response = datasetResource.getDatasetCoverUrl(
+      baseDataset.getDid,
+      Optional.of(sessionUser)
+    )
+
+    response.getStatus shouldEqual 200
+    Option(entityAsScalaMap(response)("url")) shouldBe empty
+  }
+
   "LakeFS error handling" should "return 500 when ETag is invalid, with the message included in the error response body" in {
     val filePath = uniqueFilePath("error-body")
 

frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.html

@@ -118,13 +118,10 @@ <h2>Dataset: {{datasetName}}</h2>
         </div>
       </div>
       <img
-        *ngIf="coverImageUrl; else coverPlaceholder"
+        *ngIf="coverImageUrl"
         class="dataset-cover-image"
         [src]="coverImageUrl"
         alt="Dataset cover" />
-      <ng-template #coverPlaceholder>
-        <div class="dataset-cover-image"></div>
-      </ng-template>
     </div>
 
     <div class="description-section">

frontend/src/app/dashboard/component/user/user-dataset/user-dataset-explorer/dataset-detail.component.ts

@@ -67,12 +67,10 @@ import { FilesUploaderComponent } from "../../files-uploader/files-uploader.comp
 import { NzProgressComponent } from "ng-zorro-antd/progress";
 import { UserDatasetStagedObjectsListComponent } from "./user-dataset-staged-objects-list/user-dataset-staged-objects-list.component";
 import { NzInputDirective } from "ng-zorro-antd/input";
-import { AppSettings } from "../../../../../common/app-setting";
 
 export const THROTTLE_TIME_MS = 1000;
 export const ABORT_RETRY_MAX_ATTEMPTS = 10;
 export const ABORT_RETRY_BACKOFF_BASE_MS = 100;
-const DEFAULT_COVER_IMAGE = "assets/card_background.jpg";
 
 @UntilDestroy()
 @Component({
@@ -121,7 +119,7 @@ export class DatasetDetailComponent implements OnInit {
   public datasetCreationTime: string = "";
   public datasetCreationTimeTooltip: string = "";
   public datasetIsPublic: boolean = false;
-  public coverImageUrl: string = "";
+  public coverImageUrl: string | null = null;
   public datasetIsDownloadable: boolean = true;
   public userDatasetAccessLevel: "READ" | "WRITE" | "NONE" = "NONE";
   public ownerEmail: string = "";
@@ -332,8 +330,9 @@ export class DatasetDetailComponent implements OnInit {
 
   retrieveDatasetInfo() {
     if (this.did) {
+      const did = this.did;
       this.datasetService
-        .getDataset(this.did, this.isLogin)
+        .getDataset(did, this.isLogin)
         .pipe(untilDestroyed(this))
         .subscribe(dashboardDataset => {
           const dataset = dashboardDataset.dataset;
@@ -344,9 +343,17 @@ export class DatasetDetailComponent implements OnInit {
           this.datasetIsDownloadable = dataset.isDownloadable;
           this.ownerEmail = dashboardDataset.ownerEmail;
           this.isOwner = dashboardDataset.isOwner;
-          this.coverImageUrl = dataset.coverImage
-            ? `${AppSettings.getApiEndpoint()}/dataset/${this.did}/cover?v=${encodeURIComponent(dataset.coverImage)}`
-            : DEFAULT_COVER_IMAGE;
+          if (dataset.coverImage) {
+            this.datasetService
+              .getDatasetCoverUrl(did)
+              .pipe(untilDestroyed(this))
+              .subscribe({
+                next: ({ url }) => (this.coverImageUrl = url),
+                error: () => (this.coverImageUrl = null),
+              });
+          } else {
+            this.coverImageUrl = null;
+          }
           if (typeof dataset.creationTime === "number") {
             const date = new Date(dataset.creationTime);
             this.datasetCreationTime = format(date, "MM/dd/yyyy HH:mm:ss");
@@ -776,14 +783,21 @@ export class DatasetDetailComponent implements OnInit {
     if (!this.did || !this.selectedVersion) {
       return;
     }
+    const did = this.did;
 
     const newCoverPath = `${this.selectedVersion.name}/${filePath}`;
     this.datasetService
-      .updateDatasetCoverImage(this.did, newCoverPath)
+      .updateDatasetCoverImage(did, newCoverPath)
       .pipe(untilDestroyed(this))
       .subscribe({
         next: () => {
-          this.coverImageUrl = `${AppSettings.getApiEndpoint()}/dataset/${this.did}/cover?v=${encodeURIComponent(newCoverPath)}`;
+          this.datasetService
+            .getDatasetCoverUrl(did)
+            .pipe(untilDestroyed(this))
+            .subscribe({
+              next: ({ url }) => (this.coverImageUrl = url),
+              error: () => (this.coverImageUrl = null),
+            });
           this.notificationService.success("Cover image updated.");
         },
         error: (err: unknown) => {

frontend/src/app/dashboard/service/user/dataset/dataset.service.ts

@@ -557,4 +557,8 @@ export class DatasetService {
       coverImage: coverImage,
     });
   }
+
+  public getDatasetCoverUrl(did: number): Observable<{ url: string | null }> {
+    return this.http.get<{ url: string | null }>(`${AppSettings.getApiEndpoint()}/dataset/${did}/cover-url`);
+  }
 }