JS -- Add listener for sandbox events only if there are some actions

* When no actions then set it to null instead of empty object
* Even if a field has no actions, it needs to listen to events from the sandbox in order to be updated if an action changes something in it.

src/core/annotation.js

@@ -59,25 +59,39 @@ class AnnotationFactory {
    * @param {Object} ref
    * @param {PDFManager} pdfManager
    * @param {Object} idFactory
+   * @param {boolean} checkJSActions
    * @returns {Promise} A promise that is resolved with an {Annotation}
    *   instance.
    */
-  static create(xref, ref, pdfManager, idFactory) {
-    return pdfManager.ensureCatalog("acroForm").then(acroForm => {
+  static create(xref, ref, pdfManager, idFactory, checkJSActions = true) {
+    return Promise.all([
+      pdfManager.ensureCatalog("acroForm"),
+      checkJSActions
+        ? pdfManager.ensureDoc("hasJSActions")
+        : Promise.resolve(false),
+    ]).then(([acroForm, hasJSActions]) => {
       return pdfManager.ensure(this, "_create", [
         xref,
         ref,
         pdfManager,
         idFactory,
         acroForm,
+        hasJSActions,
       ]);
     });
   }
 
   /**
    * @private
    */
-  static _create(xref, ref, pdfManager, idFactory, acroForm) {
+  static _create(
+    xref,
+    ref,
+    pdfManager,
+    idFactory,
+    acroForm,
+    hasJSActions = false
+  ) {
     const dict = xref.fetchIfRef(ref);
     if (!isDict(dict)) {
       return undefined;
@@ -98,6 +112,7 @@ class AnnotationFactory {
       id,
       pdfManager,
       acroForm: acroForm instanceof Dict ? acroForm : Dict.empty,
+      hasJSActions,
     };
 
     switch (subtype) {
@@ -282,6 +297,7 @@ class Annotation {
       modificationDate: this.modificationDate,
       rect: this.rectangle,
       subtype: params.subtype,
+      documentHasJSActions: params.hasJSActions,
     };
 
     this._fallbackFontDict = null;

src/core/document.js

@@ -962,12 +962,14 @@ class PDFDocument {
     if (!(name in promises)) {
       promises.set(name, []);
     }
+
     promises.get(name).push(
       AnnotationFactory.create(
         this.xref,
         fieldRef,
         this.pdfManager,
-        this._localIdFactory
+        this._localIdFactory,
+        /* checkJSActions */ false
       )
         .then(annotation => annotation && annotation.getFieldObject())
         .catch(function (reason) {
@@ -1014,6 +1016,26 @@ class PDFDocument {
     );
   }
 
+  get hasJSActions() {
+    return shadow(
+      this,
+      "hasJSActions",
+      this.fieldObjects.then(objects => {
+        if (objects === null) {
+          return false;
+        }
+        for (const object of Object.values(objects)) {
+          for (const obj of object) {
+            if (obj.actions !== null) {
+              return true;
+            }
+          }
+        }
+        return false;
+      })
+    );
+  }
+
   get calculationOrderIds() {
     const acroForm = this.catalog.acroForm;
     if (!acroForm || !acroForm.has("CO")) {

src/core/worker.js

@@ -524,6 +524,10 @@ class WorkerMessageHandler {
       return pdfManager.ensureDoc("fieldObjects");
     });
 
+    handler.on("HasJSActions", function (data) {
+      return pdfManager.ensureDoc("hasJSActions");
+    });
+
     handler.on("GetCalculationOrderIds", function (data) {
       return pdfManager.ensureDoc("calculationOrderIds");
     });

src/display/annotation_layer.js

@@ -142,6 +142,7 @@ class AnnotationElement {
     this.renderInteractiveForms = parameters.renderInteractiveForms;
     this.svgFactory = parameters.svgFactory;
     this.annotationStorage = parameters.annotationStorage;
+    this.enableScripting = parameters.enableScripting;
 
     if (isRenderable) {
       this.container = this._createContainer(ignoreBorder);
@@ -478,7 +479,7 @@ class TextWidgetAnnotationElement extends WidgetAnnotationElement {
         event.target.setSelectionRange(0, 0);
       });
 
-      if (this.data.actions) {
+      if (this.enableScripting && this.data.documentHasJSActions) {
         element.addEventListener("updateFromSandbox", function (event) {
           const data = event.detail;
           if ("value" in data) {
@@ -488,21 +489,23 @@ class TextWidgetAnnotationElement extends WidgetAnnotationElement {
           }
         });
 
-        for (const eventType of Object.keys(this.data.actions)) {
-          switch (eventType) {
-            case "Format":
-              element.addEventListener("blur", function (event) {
-                window.dispatchEvent(
-                  new CustomEvent("dispatchEventInSandbox", {
-                    detail: {
-                      id,
-                      name: "Format",
-                      value: event.target.value,
-                    },
-                  })
-                );
-              });
-              break;
+        if (this.data.actions !== null) {
+          for (const eventType of Object.keys(this.data.actions)) {
+            switch (eventType) {
+              case "Format":
+                element.addEventListener("blur", function (event) {
+                  window.dispatchEvent(
+                    new CustomEvent("dispatchEventInSandbox", {
+                      detail: {
+                        id,
+                        name: "Format",
+                        value: event.target.value,
+                      },
+                    })
+                  );
+                });
+                break;
+            }
           }
         }
       }
@@ -1565,6 +1568,7 @@ class AnnotationLayer {
         svgFactory: new DOMSVGFactory(),
         annotationStorage:
           parameters.annotationStorage || new AnnotationStorage(),
+        enableScripting: parameters.enableScripting,
       });
       if (element.isRenderable) {
         parameters.div.appendChild(element.render());

src/display/api.js

@@ -903,6 +903,14 @@ class PDFDocumentProxy {
     return this._transport.getFieldObjects();
   }
 
+  /**
+   * @returns {Promise<Boolean>} A promise that is resolved with true if
+   * there are some actions in JavaScript.
+   */
+  hasJSActions() {
+    return this._transport.hasJSActions();
+  }
+
   /**
    * @returns {Promise<Array<string> | null>} A promise that is resolved with an
    *   {Array<string>} containing IDs of annotations that have a calculation
@@ -2581,6 +2589,10 @@ class WorkerTransport {
     return this.messageHandler.sendWithPromise("GetFieldObjects", null);
   }
 
+  hasJSActions() {
+    return this.messageHandler.sendWithPromise("HasJSActions", null);
+  }
+
   getCalculationOrderIds() {
     return this.messageHandler.sendWithPromise("GetCalculationOrderIds", null);
   }

src/scripting_api/field.js

@@ -73,12 +73,14 @@ class Field extends PDFObject {
     // Private
     this._actions = Object.create(null);
     const doc = (this._document = data.doc);
-    for (const [eventType, actions] of Object.entries(data.actions)) {
-      // This code is running in a sandbox so it's safe to use Function
-      this._actions[eventType] = actions.map(action =>
-        // eslint-disable-next-line no-new-func
-        Function("event", `with (this) {${action}}`).bind(doc)
-      );
+    if (data.actions !== null) {
+      for (const [eventType, actions] of Object.entries(data.actions)) {
+        // This code is running in a sandbox so it's safe to use Function
+        this._actions[eventType] = actions.map(action =>
+          // eslint-disable-next-line no-new-func
+          Function("event", `with (this) {${action}}`).bind(doc)
+        );
+      }
     }
   }
 

test/unit/annotation_spec.js

@@ -61,6 +61,10 @@ describe("annotation", function () {
     ensureCatalog(prop, args) {
       return this.ensure(this.pdfDocument.catalog, prop, args);
     }
+
+    ensureDoc(prop, args) {
+      return this.ensure(this.pdfDocument, prop, args);
+    }
   }
 
   function HandlerMock() {

test/unit/document_spec.js

@@ -239,5 +239,60 @@ describe("document", function () {
       expect(fields["parent.kid2"]).toEqual(["265R"]);
       expect(fields.parent).toEqual(["358R"]);
     });
+
+    it("should check if fields have any actions", async function () {
+      const acroForm = new Dict();
+
+      let pdfDocument = getDocument(acroForm);
+      let hasJSActions = await pdfDocument.hasJSActions;
+      expect(hasJSActions).toEqual(false);
+
+      acroForm.set("Fields", []);
+      pdfDocument = getDocument(acroForm);
+      hasJSActions = await pdfDocument.hasJSActions;
+      expect(hasJSActions).toEqual(false);
+
+      const kid1Ref = Ref.get(314, 0);
+      const kid11Ref = Ref.get(159, 0);
+      const kid2Ref = Ref.get(265, 0);
+      const parentRef = Ref.get(358, 0);
+
+      const allFields = Object.create(null);
+      for (const name of ["parent", "kid1", "kid2", "kid11"]) {
+        const buttonWidgetDict = new Dict();
+        buttonWidgetDict.set("Type", Name.get("Annot"));
+        buttonWidgetDict.set("Subtype", Name.get("Widget"));
+        buttonWidgetDict.set("FT", Name.get("Btn"));
+        buttonWidgetDict.set("T", name);
+        allFields[name] = buttonWidgetDict;
+      }
+
+      allFields.kid1.set("Kids", [kid11Ref]);
+      allFields.parent.set("Kids", [kid1Ref, kid2Ref]);
+
+      const xref = new XRefMock([
+        { ref: parentRef, data: allFields.parent },
+        { ref: kid1Ref, data: allFields.kid1 },
+        { ref: kid11Ref, data: allFields.kid11 },
+        { ref: kid2Ref, data: allFields.kid2 },
+      ]);
+
+      acroForm.set("Fields", [parentRef]);
+      pdfDocument = getDocument(acroForm, xref);
+      hasJSActions = await pdfDocument.hasJSActions;
+      expect(hasJSActions).toEqual(false);
+
+      const JS = Name.get("JavaScript");
+      const additionalActionsDict = new Dict();
+      const eDict = new Dict();
+      eDict.set("JS", "hello()");
+      eDict.set("S", JS);
+      additionalActionsDict.set("E", eDict);
+      allFields.kid2.set("AA", additionalActionsDict);
+
+      pdfDocument = getDocument(acroForm, xref);
+      hasJSActions = await pdfDocument.hasJSActions;
+      expect(hasJSActions).toEqual(true);
+    });
   });
 });

web/annotation_layer_builder.js

@@ -28,6 +28,7 @@ import { SimpleLinkService } from "./pdf_link_service.js";
  * @property {IPDFLinkService} linkService
  * @property {DownloadManager} downloadManager
  * @property {IL10n} l10n - Localization service.
+ * @property {boolean} enableScripting
  */
 
 class AnnotationLayerBuilder {
@@ -43,6 +44,7 @@ class AnnotationLayerBuilder {
     imageResourcesPath = "",
     renderInteractiveForms = true,
     l10n = NullL10n,
+    enableScripting = false,
   }) {
     this.pageDiv = pageDiv;
     this.pdfPage = pdfPage;
@@ -52,6 +54,7 @@ class AnnotationLayerBuilder {
     this.renderInteractiveForms = renderInteractiveForms;
     this.l10n = l10n;
     this.annotationStorage = annotationStorage;
+    this.enableScripting = enableScripting;
 
     this.div = null;
     this._cancelled = false;
@@ -82,6 +85,7 @@ class AnnotationLayerBuilder {
         linkService: this.linkService,
         downloadManager: this.downloadManager,
         annotationStorage: this.annotationStorage,
+        enableScripting: this.enableScripting,
       };
 
       if (this.div) {
@@ -126,6 +130,7 @@ class DefaultAnnotationLayerFactory {
    *   for annotation icons. Include trailing slash.
    * @param {boolean} renderInteractiveForms
    * @param {IL10n} l10n
+   * @param {boolean} enableScripting
    * @returns {AnnotationLayerBuilder}
    */
   createAnnotationLayerBuilder(
@@ -134,7 +139,8 @@ class DefaultAnnotationLayerFactory {
     annotationStorage = null,
     imageResourcesPath = "",
     renderInteractiveForms = true,
-    l10n = NullL10n
+    l10n = NullL10n,
+    enableScripting = false
   ) {
     return new AnnotationLayerBuilder({
       pageDiv,
@@ -144,6 +150,7 @@ class DefaultAnnotationLayerFactory {
       linkService: new SimpleLinkService(),
       l10n,
       annotationStorage,
+      enableScripting,
     });
   }
 }

web/app.js

@@ -449,6 +449,7 @@ const PDFViewerApplication = {
       enablePrintAutoRotate: AppOptions.get("enablePrintAutoRotate"),
       useOnlyCssZoom: AppOptions.get("useOnlyCssZoom"),
       maxCanvasPixels: AppOptions.get("maxCanvasPixels"),
+      enableScripting: AppOptions.get("enableScripting"),
     });
     pdfRenderingQueue.setViewer(this.pdfViewer);
     pdfLinkService.setViewer(this.pdfViewer);