The survey.onValueChanging event is not raised when updating a matrix…

src/survey.ts

@@ -5623,15 +5623,15 @@ export class SurveyModel extends SurveyElementCore
     page.name = name;
     return page;
   }
-  protected questionOnValueChanging(valueName: string, newValue: any): any {
+  protected questionOnValueChanging(valueName: string, newValue: any, questionValueName?: string): any {
     if (!!this.editingObj) {
       const prop = Serializer.findProperty(this.editingObj.getType(), valueName);
       if (!!prop) newValue = prop.settingValue(this.editingObj, newValue);
     }
     if (this.onValueChanging.isEmpty) return newValue;
     var options = {
       name: valueName,
-      question: <Question>this.getQuestionByValueName(valueName),
+      question: <Question>this.getQuestionByValueName(questionValueName || valueName),
       value: this.getUnbindValue(newValue),
       oldValue: this.getValue(valueName),
     };
@@ -6600,7 +6600,8 @@ export class SurveyModel extends SurveyElementCore
   public setComment(name: string, newValue: string, locNotification: any = false): void {
     if (!newValue) newValue = "";
     if (this.isTwoValueEquals(newValue, this.getComment(name))) return;
-    var commentName = name + this.commentSuffix;
+    const commentName = name + this.commentSuffix;
+    newValue = this.questionOnValueChanging(commentName, newValue, name);
     if (this.isValueEmpty(newValue)) {
       this.deleteDataValueCore(this.valuesHash, commentName);
     } else {
@@ -6626,6 +6627,10 @@ export class SurveyModel extends SurveyElementCore
         question: question,
         value: newValue,
       });
+      question.comment = newValue;
+      if(question.comment != newValue) {
+        question.comment = newValue;
+      }
     }
   }
   /**

tests/surveytests.ts

@@ -1881,7 +1881,70 @@ QUnit.test("onValueChanging event", function (assert) {
     "onValueChanging event allows to change value"
   );
 });
-QUnit.test("onValueChanging event - do not allow clear value, #1542", function (
+QUnit.test("onValueChanging event for comment, #8292", function (
+  assert
+) {
+  const survey = new SurveyModel();
+  const page = survey.addNewPage("page");
+  const q1 = page.addNewQuestion("text", "q1");
+  q1.showCommentArea = true;
+  let oldComment, newComment, questionName;
+  survey.onValueChanging.add((sender, options) => {
+    if (options.name == "q1-Comment") {
+      questionName = options.question.name;
+      oldComment = options.oldValue;
+      newComment = options.value;
+    }
+  });
+  q1.comment = "abc";
+  assert.equal(questionName, "q1", "question name #1");
+  assert.equal(q1.comment, "abc", "comment value #1");
+  assert.equal(newComment, "abc", "newComment #1");
+  q1.comment = "abcd";
+  assert.equal(q1.comment, "abcd", "comment value #2");
+  assert.equal(newComment, "abcd", "newComment #2");
+  assert.equal(oldComment, "abc", "newComment #2");
+});
+
+QUnit.test("onValueChanging event - do not allow clear value, #8292", function (
+  assert
+) {
+  const survey = new SurveyModel();
+  const page = survey.addNewPage("page");
+  const q1 = page.addNewQuestion("text", "q1");
+  q1.showCommentArea = true;
+  let counter = 0;
+  let oldComment, newComment, questionName;
+  survey.onValueChanging.add((sender, options) => {
+    if (options.name === "q1-Comment") {
+      counter ++;
+      questionName = options.question.name;
+      if(!options.value) {
+        options.value = options.oldValue;
+      }
+      oldComment = options.oldValue;
+      newComment = options.value;
+    }
+  });
+  let onValueChangedValue;
+  survey.onValueChanged.add((sender, options) => {
+    if (options.name === "q1-Comment") {
+      onValueChangedValue = options.value;
+    }
+  });
+  q1.comment = "abc";
+  assert.equal(counter, 1, "counter #1");
+  assert.equal(q1.comment, "abc", "comment value #1");
+  q1.comment = "";
+  assert.equal(questionName, "q1", "question.name #2");
+  assert.equal(oldComment, "abc", "oldComment #2");
+  assert.equal(newComment, "abc", "newComment #2");
+  assert.equal(counter, 2, "counter #2");
+  assert.equal(q1.comment, "abc", "comment value #2");
+  assert.equal(survey.getComment("q1"), "abc", "survey.getComment value #2");
+  assert.equal(onValueChangedValue, "abc", "onValueChanged options.value");
+});
+QUnit.test("onValueChanging event - do not allow clear value in comment, #1542", function (
   assert
 ) {
   var survey = new SurveyModel();