[api-minor] Add partial support for the "GoToE" action (issue 8844)

*Please note:* The referenced issue is the only mention that I can find, in either GitHub or Bugzilla, of "GoToE" actions.
Hence why I've purposely settled for a very simple, and partial, "GoToE" implementation to avoid complicating things initially.[1] In particular, this patch only supports "GoToE" actions that references the /EmbeddedFiles-dict in the PDF document.

See https://web.archive.org/web/20220309040754if_/https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/PDF32000_2008.pdf#G11.2048909

---
[1] Usually I always prefer having *real-world* test-cases to work with, whenever I'm implementing new features.

src/core/annotation.js

@@ -80,15 +80,19 @@ class AnnotationFactory {
       // Only necessary to prevent the `pdfManager.docBaseUrl`-getter, used
       // with certain Annotations, from throwing and thus breaking parsing:
       pdfManager.ensureCatalog("baseUrl"),
+      // Only necessary in the `Catalog.parseDestDictionary`-method,
+      // when parsing "GoToE" actions:
+      pdfManager.ensureCatalog("attachments"),
       pdfManager.ensureDoc("xfaDatasets"),
       collectFields ? this._getPageIndex(xref, ref, pdfManager) : -1,
-    ]).then(([acroForm, baseUrl, xfaDatasets, pageIndex]) =>
+    ]).then(([acroForm, baseUrl, attachments, xfaDatasets, pageIndex]) =>
       pdfManager.ensure(this, "_create", [
         xref,
         ref,
         pdfManager,
         idFactory,
         acroForm,
+        attachments,
         xfaDatasets,
         collectFields,
         pageIndex,
@@ -105,6 +109,7 @@ class AnnotationFactory {
     pdfManager,
     idFactory,
     acroForm,
+    attachments = null,
     xfaDatasets,
     collectFields,
     pageIndex = -1
@@ -130,6 +135,7 @@ class AnnotationFactory {
       id,
       pdfManager,
       acroForm: acroForm instanceof Dict ? acroForm : Dict.empty,
+      attachments,
       xfaDatasets,
       collectFields,
       pageIndex,
@@ -2893,6 +2899,7 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
       destDict: params.dict,
       resultObj: this.data,
       docBaseUrl: params.pdfManager.docBaseUrl,
+      docAttachments: params.attachments,
     });
   }
 
@@ -3221,6 +3228,7 @@ class LinkAnnotation extends Annotation {
       destDict: params.dict,
       resultObj: this.data,
       docBaseUrl: params.pdfManager.docBaseUrl,
+      docAttachments: params.attachments,
     });
   }
 }

src/core/catalog.js

@@ -307,6 +307,7 @@ class Catalog {
         destDict: outlineDict,
         resultObj: data,
         docBaseUrl: this.pdfManager.docBaseUrl,
+        docAttachments: this.attachments,
       });
       const title = outlineDict.get("Title");
       const flags = outlineDict.get("F") || 0;
@@ -325,6 +326,7 @@ class Catalog {
 
       const outlineItem = {
         action: data.action,
+        attachment: data.attachment,
         dest: data.dest,
         url: data.url,
         unsafeUrl: data.unsafeUrl,
@@ -1412,6 +1414,8 @@ class Catalog {
    *   properties will be placed.
    * @property {string} [docBaseUrl] - The document base URL that is used when
    *   attempting to recover valid absolute URLs from relative ones.
+   * @property {Object} [docAttachments] - The document attachments (may not
+   *   exist in most PDF documents).
    */
 
   /**
@@ -1430,6 +1434,7 @@ class Catalog {
       return;
     }
     const docBaseUrl = params.docBaseUrl || null;
+    const docAttachments = params.docAttachments || null;
 
     let action = destDict.get("A"),
       url,
@@ -1526,6 +1531,26 @@ class Catalog {
           }
           break;
 
+        case "GoToE":
+          const target = action.get("T");
+          let attachment;
+
+          if (docAttachments && target instanceof Dict) {
+            const relationship = target.get("R");
+            const name = target.get("N");
+
+            if (isName(relationship, "C") && typeof name === "string") {
+              attachment = docAttachments[stringToPDFString(name)];
+            }
+          }
+
+          if (attachment) {
+            resultObj.attachment = attachment;
+          } else {
+            warn(`parseDestDictionary - unimplemented "GoToE" action.`);
+          }
+          break;
+
         case "Named":
           const namedAction = action.get("N");
           if (namedAction instanceof Name) {

src/display/annotation_layer.js

@@ -595,6 +595,9 @@ class LinkAnnotationElement extends AnnotationElement {
     } else if (data.action) {
       this._bindNamedAction(link, data.action);
       isBound = true;
+    } else if (data.attachment) {
+      this._bindAttachment(link, data.attachment);
+      isBound = true;
     } else if (data.setOCGState) {
       this.#bindSetOCGState(link, data.setOCGState);
       isBound = true;
@@ -679,6 +682,24 @@ class LinkAnnotationElement extends AnnotationElement {
     link.className = "internalLink";
   }
 
+  /**
+   * Bind attachments to the link element.
+   * @param {Object} link
+   * @param {Object} attachment
+   */
+  _bindAttachment(link, attachment) {
+    link.href = this.linkService.getAnchorUrl("");
+    link.onclick = () => {
+      this.downloadManager?.openOrDownloadData(
+        this.container,
+        attachment.content,
+        attachment.filename
+      );
+      return false;
+    };
+    link.className = "internalLink";
+  }
+
   /**
    * Bind SetOCGState actions to the link element.
    * @param {Object} link

test/pdfs/.gitignore

@@ -49,6 +49,7 @@
 !issue7426.pdf
 !issue7439.pdf
 !issue7847_radial.pdf
+!issue8844.pdf
 !issue14953.pdf
 !issue15367.pdf
 !issue15372.pdf

test/unit/api_spec.js

@@ -15,6 +15,7 @@
 
 import {
   AnnotationMode,
+  AnnotationType,
   createPromiseCapability,
   FontType,
   ImageKind,
@@ -1536,6 +1537,7 @@ describe("api", function () {
 
       expect(outline[4]).toEqual({
         action: null,
+        attachment: undefined,
         dest: "Händel -- Halle🎆lujah",
         url: null,
         unsafeUrl: undefined,
@@ -1562,6 +1564,7 @@ describe("api", function () {
 
       expect(outline[1]).toEqual({
         action: "PrevPage",
+        attachment: undefined,
         dest: null,
         url: null,
         unsafeUrl: undefined,
@@ -1588,6 +1591,7 @@ describe("api", function () {
 
       expect(outline[0]).toEqual({
         action: null,
+        attachment: undefined,
         dest: null,
         url: null,
         unsafeUrl: undefined,
@@ -2155,6 +2159,23 @@ describe("api", function () {
       ]);
     });
 
+    it("gets annotations containing GoToE action (issue 8844)", async function () {
+      const loadingTask = getDocument(buildGetDocumentParams("issue8844.pdf"));
+      const pdfDoc = await loadingTask.promise;
+      const pdfPage = await pdfDoc.getPage(1);
+      const annotations = await pdfPage.getAnnotations();
+
+      expect(annotations.length).toEqual(1);
+      expect(annotations[0].annotationType).toEqual(AnnotationType.LINK);
+
+      const { filename, content } = annotations[0].attachment;
+      expect(filename).toEqual("man.pdf");
+      expect(content instanceof Uint8Array).toEqual(true);
+      expect(content.length).toEqual(4508);
+
+      await loadingTask.destroy();
+    });
+
     it("gets text content", async function () {
       const defaultPromise = page.getTextContent();
       const parametersPromise = page.getTextContent({

web/app.js

@@ -636,6 +636,7 @@ const PDFViewerApplication = {
       container: appConfig.sidebar.outlineView,
       eventBus,
       linkService: pdfLinkService,
+      downloadManager,
     });
 
     this.pdfAttachmentViewer = new PDFAttachmentViewer({

web/pdf_outline_viewer.js

@@ -20,8 +20,9 @@ import { SidebarView } from "./ui_utils.js";
 /**
  * @typedef {Object} PDFOutlineViewerOptions
  * @property {HTMLDivElement} container - The viewer element.
- * @property {IPDFLinkService} linkService - The navigation/linking service.
  * @property {EventBus} eventBus - The application event bus.
+ * @property {IPDFLinkService} linkService - The navigation/linking service.
+ * @property {DownloadManager} downloadManager - The download manager.
  */
 
 /**
@@ -37,6 +38,7 @@ class PDFOutlineViewer extends BaseTreeViewer {
   constructor(options) {
     super(options);
     this.linkService = options.linkService;
+    this.downloadManager = options.downloadManager;
 
     this.eventBus._on("toggleoutlinetree", this._toggleAllTreeItems.bind(this));
     this.eventBus._on(
@@ -109,7 +111,10 @@ class PDFOutlineViewer extends BaseTreeViewer {
   /**
    * @private
    */
-  _bindLink(element, { url, newWindow, action, dest, setOCGState }) {
+  _bindLink(
+    element,
+    { url, newWindow, action, attachment, dest, setOCGState }
+  ) {
     const { linkService } = this;
 
     if (url) {
@@ -124,6 +129,18 @@ class PDFOutlineViewer extends BaseTreeViewer {
       };
       return;
     }
+    if (attachment) {
+      element.href = linkService.getAnchorUrl("");
+      element.onclick = () => {
+        this.downloadManager.openOrDownloadData(
+          element,
+          attachment.content,
+          attachment.filename
+        );
+        return false;
+      };
+      return;
+    }
     if (setOCGState) {
       element.href = linkService.getAnchorUrl("");
       element.onclick = () => {