[api-minor] Add the possibility to collect Javascript actions

src/core/annotation.js

@@ -14,12 +14,14 @@
  */
 
 import {
+  AnnotationActionEventType,
   AnnotationBorderStyleType,
   AnnotationFieldFlag,
   AnnotationFlag,
   AnnotationReplyType,
   AnnotationType,
   assert,
+  bytesToString,
   escapeString,
   getModificationDate,
   isString,
@@ -30,7 +32,15 @@ import {
   warn,
 } from "../shared/util.js";
 import { Catalog, FileSpec, ObjectLoader } from "./obj.js";
-import { Dict, isDict, isName, isRef, isStream, Name } from "./primitives.js";
+import {
+  Dict,
+  isDict,
+  isName,
+  isRef,
+  isStream,
+  Name,
+  RefSet,
+} from "./primitives.js";
 import { ColorSpace } from "./colorspace.js";
 import { getInheritableProperty } from "./core_utils.js";
 import { OperatorList } from "./operator_list.js";
@@ -569,6 +579,20 @@ class Annotation {
     return null;
   }
 
+  /**
+   * Get field data for usage in JS sandbox.
+   *
+   * Field object is defined here:
+   * https://www.adobe.com/content/dam/acom/en/devnet/acrobat/pdfs/js_api_reference.pdf#page=16
+   *
+   * @public
+   * @memberof Annotation
+   * @returns {Object | null}
+   */
+  getFieldObject() {
+    return null;
+  }
+
   /**
    * Reset the annotation.
    *
@@ -903,6 +927,7 @@ class WidgetAnnotation extends Annotation {
 
     data.annotationType = AnnotationType.WIDGET;
     data.fieldName = this._constructFieldName(dict);
+    data.actions = this._collectActions(params.xref, dict);
 
     const fieldValue = getInheritableProperty({
       dict,
@@ -937,13 +962,15 @@ class WidgetAnnotation extends Annotation {
     }
 
     data.readOnly = this.hasFieldFlag(AnnotationFieldFlag.READONLY);
+    data.hidden = this.hasFieldFlag(AnnotationFieldFlag.HIDDEN);
 
     // Hide signatures because we cannot validate them, and unset the fieldValue
     // since it's (most likely) a `Dict` which is non-serializable and will thus
     // cause errors when sending annotations to the main-thread (issue 10347).
     if (data.fieldType === "Sig") {
       data.fieldValue = null;
       this.setFlags(AnnotationFlag.HIDDEN);
+      data.hidden = true;
     }
   }
 
@@ -1366,6 +1393,87 @@ class WidgetAnnotation extends Annotation {
     }
     return localResources || Dict.empty;
   }
+
+  _collectJS(entry, xref, list, parents) {
+    if (!entry) {
+      return;
+    }
+
+    let parent = null;
+    if (isRef(entry)) {
+      if (parents.has(entry)) {
+        // If we've already found entry then we've a cycle.
+        return;
+      }
+      parent = entry;
+      parents.put(parent);
+      entry = xref.fetch(entry);
+    }
+    if (Array.isArray(entry)) {
+      for (const element of entry) {
+        this._collectJS(element, xref, list, parents);
+      }
+    } else if (entry instanceof Dict) {
+      if (isName(entry.get("S"), "JavaScript") && entry.has("JS")) {
+        const js = entry.get("JS");
+        let code;
+        if (isStream(js)) {
+          code = bytesToString(js.getBytes());
+        } else {
+          code = js;
+        }
+        code = stringToPDFString(code);
+        if (code) {
+          list.push(code);
+        }
+      }
+      this._collectJS(entry.getRaw("Next"), xref, list, parents);
+    }
+
+    if (parent) {
+      parents.remove(parent);
+    }
+  }
+
+  _collectActions(xref, dict) {
+    const actions = Object.create(null);
+    if (dict.has("AA")) {
+      const additionalActions = dict.get("AA");
+      for (const key of additionalActions.getKeys()) {
+        if (key in AnnotationActionEventType) {
+          const actionDict = additionalActions.getRaw(key);
+          const parents = new RefSet();
+          const list = [];
+          this._collectJS(actionDict, xref, list, parents);
+          if (list.length > 0) {
+            actions[AnnotationActionEventType[key]] = list;
+          }
+        }
+      }
+    }
+    // Collect the Action if any (we may have one on pushbutton)
+    if (dict.has("A")) {
+      const actionDict = dict.get("A");
+      const parents = new RefSet();
+      const list = [];
+      this._collectJS(actionDict, xref, list, parents);
+      if (list.length > 0) {
+        actions.Action = list;
+      }
+    }
+    return actions;
+  }
+
+  getFieldObject() {
+    if (this.data.fieldType === "Sig") {
+      return {
+        id: this.data.id,
+        value: null,
+        type: "signature",
+      };
+    }
+    return null;
+  }
 }
 
 class TextWidgetAnnotation extends WidgetAnnotation {
@@ -1516,6 +1624,23 @@ class TextWidgetAnnotation extends WidgetAnnotation {
 
     return chunks;
   }
+
+  getFieldObject() {
+    return {
+      id: this.data.id,
+      value: this.data.fieldValue,
+      multiline: this.data.multiLine,
+      password: this.hasFieldFlag(AnnotationFieldFlag.PASSWORD),
+      charLimit: this.data.maxLen,
+      comb: this.data.comb,
+      editable: !this.data.readOnly,
+      hidden: this.data.hidden,
+      name: this.data.fieldName,
+      rect: this.data.rect,
+      actions: this.data.actions,
+      type: "text",
+    };
+  }
 }
 
 class ButtonWidgetAnnotation extends WidgetAnnotation {
@@ -1793,6 +1918,28 @@ class ButtonWidgetAnnotation extends WidgetAnnotation {
       docBaseUrl: params.pdfManager.docBaseUrl,
     });
   }
+
+  getFieldObject() {
+    let type = "button";
+    let value = null;
+    if (this.data.checkBox) {
+      type = "checkbox";
+      value = this.data.fieldValue && this.data.fieldValue !== "Off";
+    } else if (this.data.radioButton) {
+      type = "radiobutton";
+      value = this.data.fieldValue === this.data.buttonValue;
+    }
+    return {
+      id: this.data.id,
+      value,
+      editable: !this.data.readOnly,
+      name: this.data.fieldName,
+      rect: this.data.rect,
+      hidden: this.data.hidden,
+      actions: this.data.actions,
+      type,
+    };
+  }
 }
 
 class ChoiceWidgetAnnotation extends WidgetAnnotation {
@@ -1843,6 +1990,23 @@ class ChoiceWidgetAnnotation extends WidgetAnnotation {
     this.data.multiSelect = this.hasFieldFlag(AnnotationFieldFlag.MULTISELECT);
     this._hasText = true;
   }
+
+  getFieldObject() {
+    const type = this.data.combo ? "combobox" : "listbox";
+    const value =
+      this.data.fieldValue.length > 0 ? this.data.fieldValue[0] : null;
+    return {
+      id: this.data.id,
+      value,
+      editable: !this.data.readOnly,
+      name: this.data.fieldName,
+      rect: this.data.rect,
+      multipleSelection: this.data.multiSelect,
+      hidden: this.data.hidden,
+      actions: this.data.actions,
+      type,
+    };
+  }
 }
 
 class TextAnnotation extends MarkupAnnotation {

src/core/document.js

@@ -708,7 +708,7 @@ class PDFDocument {
   }
 
   get formInfo() {
-    const formInfo = { hasAcroForm: false, hasXfa: false };
+    const formInfo = { hasAcroForm: false, hasXfa: false, fields: null };
     const acroForm = this.catalog.acroForm;
     if (!acroForm) {
       return shadow(this, "formInfo", formInfo);
@@ -736,6 +736,9 @@ class PDFDocument {
       const hasOnlyDocumentSignatures =
         !!(sigFlags & 0x1) && this._hasOnlyDocumentSignatures(fields);
       formInfo.hasAcroForm = hasFields && !hasOnlyDocumentSignatures;
+      if (hasFields) {
+        formInfo.fields = fields;
+      }
     } catch (ex) {
       if (ex instanceof MissingDataException) {
         throw ex;
@@ -935,6 +938,73 @@ class PDFDocument {
       ? this.catalog.cleanup(manuallyTriggered)
       : clearPrimitiveCaches();
   }
+
+  _collectFieldObjects(name, fieldRef, promises) {
+    const field = this.xref.fetchIfRef(fieldRef);
+    if (field.has("T")) {
+      const partName = stringToPDFString(field.get("T"));
+      if (name === "") {
+        name = partName;
+      } else {
+        name = `${name}.${partName}`;
+      }
+    }
+
+    if (!(name in promises)) {
+      promises.set(name, []);
+    }
+    promises.get(name).push(
+      AnnotationFactory.create(
+        this.xref,
+        fieldRef,
+        this.pdfManager,
+        this._localIdFactory
+      )
+        .then(annotation => annotation.getFieldObject())
+        .catch(function (reason) {
+          warn(`_collectFieldObjects: "${reason}".`);
+          return null;
+        })
+    );
+
+    if (field.has("Kids")) {
+      const kids = field.get("Kids");
+      for (const kid of kids) {
+        this._collectFieldObjects(name, kid, promises);
+      }
+    }
+  }
+
+  get fieldObjects() {
+    const formInfo = this.formInfo;
+    if (!formInfo.fields) {
+      return shadow(this, "fieldObjects", Promise.resolve(null));
+    }
+
+    const allFields = Object.create(null);
+    const fieldPromises = new Map();
+    for (const fieldRef of formInfo.fields) {
+      this._collectFieldObjects("", fieldRef, fieldPromises);
+    }
+
+    const allPromises = [];
+    for (const [name, promises] of fieldPromises.entries()) {
+      allPromises.push(
+        Promise.all(promises).then(fields => {
+          fields = fields.filter(field => field !== null);
+          if (fields.length > 0) {
+            allFields[name] = fields;
+          }
+        })
+      );
+    }
+
+    return shadow(
+      this,
+      "fieldObjects",
+      Promise.all(allPromises).then(() => allFields)
+    );
+  }
 }
 
 export { Page, PDFDocument };

src/core/worker.js

@@ -516,6 +516,10 @@ class WorkerMessageHandler {
       });
     });
 
+    handler.on("GetFieldObjects", function (data) {
+      return pdfManager.ensureDoc("fieldObjects");
+    });
+
     handler.on("SaveDocument", function ({
       numPages,
       annotationStorage,

src/display/api.js

@@ -876,6 +876,14 @@ class PDFDocumentProxy {
   saveDocument(annotationStorage) {
     return this._transport.saveDocument(annotationStorage);
   }
+
+  /**
+   * @returns {Promise<Array<Object>>} A promise that is resolved with an
+   *   {Array<Object>} containing field data for the JS sandbox.
+   */
+  getFieldObjects() {
+    return this._transport.getFieldObjects();
+  }
 }
 
 /**
@@ -2549,6 +2557,10 @@ class WorkerTransport {
       });
   }
 
+  getFieldObjects() {
+    return this.messageHandler.sendWithPromise("GetFieldObjects", null);
+  }
+
   getDestinations() {
     return this.messageHandler.sendWithPromise("GetDestinations", null);
   }