Allow to use copy trigger without expression fix #7030

src/trigger.ts

@@ -117,9 +117,14 @@ export class Trigger extends Base {
     if (!this.isCheckRequired(keys)) return;
     if (!!this.conditionRunner) {
       this.perform(values, properties);
+    } else {
+      if(this.canSuccessOnEmptyExpression()) {
+        this.triggerResult(true, values, properties);
+      }
     }
   }
-  public check(value: any) {
+  protected canSuccessOnEmptyExpression(): boolean { return false; }
+  public check(value: any): void {
     var triggerResult = Trigger.operators[this.operator](value, this.value);
     if (triggerResult) {
       this.onSuccess({}, null);
@@ -174,8 +179,12 @@ export class Trigger extends Base {
   private isCheckRequired(keys: any): boolean {
     if (!keys) return false;
     this.createConditionRunner();
-    if (this.conditionRunner.hasFunction() === true) return true;
-    return new ProcessValue().isAnyKeyChanged(keys, this.conditionRunner.getVariables());
+    if (this.conditionRunner && this.conditionRunner.hasFunction() === true) return true;
+    return new ProcessValue().isAnyKeyChanged(keys, this.getUsedVariables());
+  }
+  protected getUsedVariables(): string[] {
+    if(!this.conditionRunner) return [];
+    return this.conditionRunner.getVariables();
   }
   private createConditionRunner() {
     if (!!this.conditionRunner) return;
@@ -431,6 +440,14 @@ export class SurveyTriggerCopyValue extends SurveyTrigger {
     if (!this.setToName || !this.owner) return;
     this.owner.copyTriggerValue(this.setToName, this.fromName, this.copyDisplayValue);
   }
+  protected canSuccessOnEmptyExpression(): boolean { return true; }
+  protected getUsedVariables(): string[] {
+    const res = super.getUsedVariables();
+    if(res.length === 0 && !!this.fromName) {
+      res.push(this.fromName);
+    }
+    return res;
+  }
 }
 
 Serializer.addClass("trigger", [

tests/surveytriggertests.ts

@@ -392,6 +392,31 @@ QUnit.test("copyvalue from checkbox", function(assert) {
   q1.value = [1, 2];
   assert.deepEqual(q2.value, "Item1, Item2", "Copy value correctly");
 });
+QUnit.test("copyvalue without expression, bug#7030", function(assert) {
+  const survey = new SurveyModel({
+    elements: [
+      { type: "text", name: "q1" },
+      { type: "text", name: "q2" },
+      { type: "text", name: "q3" }
+
+    ],
+    "triggers": [
+      {
+        "type": "copyvalue",
+        "fromName": "q1",
+        "setToName": "q2"
+      }
+    ],
+  });
+  const q1 = survey.getQuestionByName("q1");
+  const q2 = survey.getQuestionByName("q2");
+  const q3 = survey.getQuestionByName("q3");
+  q1.value = "A";
+  assert.equal(q2.value, "A", "Copy value correctly");
+  q2.value = "B";
+  q3.value = "C";
+  assert.equal(q2.value, "B", "Do not copy value");
+});
 
 QUnit.test("Execute trigger on complete", function(assert) {
   class TriggerExprssionTester extends SurveyTriggerRunExpression {