Fix signaturepad's fromUrl method works incorrectly when question is …

…not rendered (#9030)

* Work for surveyjs/survey-pdf#348: fix signaturepad's fromUrl method works incorrectly when question is not visible

* Fix code scanning alert no. 123: Inefficient regular expression

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

* Fix regex

---------

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

packages/survey-core/src/question_signaturepad.ts

@@ -6,6 +6,7 @@ import { SurveyModel } from "./survey";
 import { ConsoleWarnings } from "./console-warnings";
 import { ITheme } from "./themes";
 import { dataUrl2File, FileLoader, QuestionFileModelBase } from "./question_file";
+import { isBase64URL } from "./utils/utils";
 
 var defaultWidth = 300;
 var defaultHeight = 200;
@@ -47,6 +48,7 @@ export class QuestionSignaturePadModel extends QuestionFileModelBase {
   }
   protected updateValue() {
     if (this.signaturePad) {
+
       var data = this.signaturePad.toDataURL(this.getFormat());
       this.valueIsUpdatingInternally = true;
       this.value = data;
@@ -107,16 +109,26 @@ export class QuestionSignaturePadModel extends QuestionFileModelBase {
 
   private fromUrl(url: string): void {
     this.isFileLoading = true;
-    const img = new Image();
-    img.crossOrigin = "anonymous";
-    img.src = url;
-    img.onload = () => {
-      const ctx = this.canvas.getContext("2d");
-      ctx.drawImage(img, 0, 0);
-      var dataURL = this.canvas.toDataURL(this.getFormat());
-      this.fromDataUrl(dataURL);
+    if(isBase64URL(url)) {
+      this.fromDataUrl(url);
       this.isFileLoading = false;
-    };
+    } else {
+      const img = new Image();
+      img.crossOrigin = "anonymous";
+      img.src = url;
+      img.onload = () => {
+        if(!!this.canvas) {
+          const ctx = this.canvas.getContext("2d");
+          ctx.drawImage(img, 0, 0);
+          var dataURL = this.canvas.toDataURL(this.getFormat());
+          this.fromDataUrl(dataURL);
+        }
+        this.isFileLoading = false;
+      };
+      img.onerror = () => {
+        this.isFileLoading = false;
+      };
+    }
   }
   private fromDataUrl(data: string) {
     this._loadedData = data;
@@ -151,10 +163,10 @@ export class QuestionSignaturePadModel extends QuestionFileModelBase {
         this._previewLoader = new FileLoader(this, (status, loaded) => {
           if (status === "success" && loaded && loaded.length > 0 && loaded[0].content) {
             this.fromDataUrl(loaded[0].content);
+            this.isFileLoading = false;
           } else if (status === "skipped") {
             this.fromUrl(newValue);
           }
-          this.isFileLoading = false;
           this._previewLoader.dispose();
           this._previewLoader = undefined;
         });

packages/survey-core/src/utils/utils.ts

@@ -163,6 +163,12 @@ function navigateToUrl(url: string): void {
 function wrapUrlForBackgroundImage(url: string): string {
   return !!url ? ["url(", url, ")"].join("") : "";
 }
+function isBase64URL(url: string): boolean {
+  if(typeof url == "string") {
+    return /^data:((?:\w+\/(?:(?!;).)+)?)((?:;[^;]+?)*),(.+)$/.test(url);
+  }
+  return null;
+}
 
 // old-name: new-name
 const renamedIcons:any = {
@@ -820,5 +826,6 @@ export {
   findParentByClassNames,
   getFirstVisibleChild,
   chooseFiles,
+  isBase64URL,
   renamedIcons
 };

packages/survey-core/tests/question_signaturepadtests.ts

@@ -608,6 +608,59 @@ QUnit.test("Check isReady flag with onDownloadFile callback", (assert) => {
   el.remove();
 });
 
+QUnit.test("Check storeDataAsText: false and base64 data", (assert) => {
+  const survey = new SurveyModel({
+    questions: [
+      {
+        type: "signaturepad",
+        name: "signature",
+        storeDataAsText: false,
+      }
+    ],
+  });
+  const question = <QuestionSignaturePadModel>survey.getAllQuestions()[0];
+  assert.equal(question.isReady, true, "question is ready before data");
+  let log = "";
+  question.onReadyChanged.add((_, opt) => {
+    log += `->${opt.isReady}`;
+  });
+  const base64Url = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAIAQMAAAD+wSzIAAAABlBMVEX///+/v7+jQ3Y5AAAADklEQVQI12P4AIX8EAgALgAD/aNpbtEAAAAASUVORK5CYII";
+  survey.data = {
+    signature: base64Url
+  };
+  assert.equal(question.loadedData, base64Url);
+  assert.equal(log, "->false->true", "isReady changed only one time");
+});
+
+QUnit.test("Check storeDataAsText: false and no download file callback and incorrect link passed", (assert) => {
+  const done = assert.async();
+  const survey = new SurveyModel({
+    questions: [
+      {
+        type: "signaturepad",
+        name: "signature",
+        storeDataAsText: false,
+      }
+    ],
+  });
+  const question = <QuestionSignaturePadModel>survey.getAllQuestions()[0];
+  assert.equal(question.isReady, true, "question is ready before data");
+  let log = "";
+  question.onReadyChanged.add((_, opt) => {
+    log += `->${opt.isReady}`;
+  });
+  const url = "http://localhost:7777/image.jpg";
+  survey.data = {
+    signature: url
+  };
+  setTimeout(() => {
+    assert.equal(question.loadedData, undefined);
+    assert.equal(question.value, url);
+    assert.equal(log, "->false->true", "isReady changed only one time");
+    done();
+  }, 100);
+});
+
 QUnit.test("Check signature image cached in loadedData and loaded only once until value changed", (assert) => {
   var el = document.createElement("div");
   var canv = document.createElement("canvas");

packages/survey-core/tests/utilstests.ts

@@ -1,6 +1,6 @@
 import { IAction } from "../src/actions/action";
 import { defaultListCss } from "../src/list";
-import { createSvg, doKey2ClickDown, doKey2ClickUp, sanitizeEditableContent, configConfirmDialog, getSafeUrl, compareArrays, setPropertiesOnElementForAnimation, cleanHtmlElementAfterAnimation } from "../src/utils/utils";
+import { createSvg, doKey2ClickDown, doKey2ClickUp, sanitizeEditableContent, configConfirmDialog, getSafeUrl, compareArrays, setPropertiesOnElementForAnimation, cleanHtmlElementAfterAnimation, isBase64URL } from "../src/utils/utils";
 import { mouseInfo, detectMouseSupport, MatchMediaMethod } from "../src/utils/devices";
 import { PopupBaseViewModel } from "../src/popup-view-model";
 import { PopupModel } from "../src/popup";
@@ -1069,4 +1069,23 @@ QUnit.test("animation helper functions", (assert) => {
   assert.equal(el["__sv_created_properties"], undefined);
   assert.equal(el.style.getPropertyValue("--animation-height"), "");
   assert.equal(el.style.getPropertyValue("--animation-margin-top"), "");
+});
+
+QUnit.test("test isBase64", (assert) => {
+  assert.ok(isBase64URL("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAIAQMAAAD+wSzIAAAABlBMVEX///+/v7+jQ3Y5AAAADklEQVQI12P4AIX8EAgALgAD/aNpbtEAAAAASUVORK5CYII"));
+  assert.ok(isBase64URL("data:image/jpg;base64,AAA"));
+  assert.ok(isBase64URL("data:image/jpeg;base64,UEsDBBQAAAAI"));
+  assert.ok(isBase64URL("data:image/jpeg;key=value;base64,UEsDBBQAAAAI"));
+  assert.ok(isBase64URL("data:image/jpeg;key=value,UEsDBBQAAAAI"));
+  assert.ok(isBase64URL("data:;base64;sdfgsdfgsdfasdfa=s,UEsDBBQAAAAI"));
+  assert.ok(isBase64URL("data:,UEsDBBQAAAAI"));
+  assert.ok(isBase64URL("data:image/jpeg;e,UEsDBBQAAAA"));
+
+  assert.notOk(isBase64URL("data:image/jpeg;base64;UEsDBBQAAAA"));
+  assert.notOk(isBase64URL("data:image/jpeg;,UEsDBBQAAAA"));
+  assert.notOk(isBase64URL("data:image/jpeg;;,UEsDBBQAAAA"));
+  assert.notOk(isBase64URL("data:image/jpeg;;e,UEsDBBQAAAA"));
+  assert.notOk(isBase64URL("iVBORw0KGgoAAAANSUhEUgAAAAgAAAAIAQMAAAD+wSzIAAAABlBMVEX///+/v7+jQ3Y5AAAADklEQVQI12P4AIX8EAgALgAD/aNpbtEAAAAASUVORK5CYII"));
+  assert.notOk(isBase64URL("image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAIAQMAAAD+wSzIAAAABlBMVEX///+/v7+jQ3Y5AAAADklEQVQI12P4AIX8EAgALgAD/aNpbtEAAAAASUVORK5CYII"));
+  assert.notOk(isBase64URL("https://localhost:7777/image.jpg"));
 });