Fix: ItemValue Property Editor, Fast Entry works slow for several hunderds items #903

Author: andrewtelnov

src/surveyHelper.ts

@@ -170,39 +170,23 @@ export class SurveyHelper {
       dest.splice(0, dest.length);
       return;
     }
-    var destHash = SurveyHelper.applyItemValueArrayCreateHash(dest);
-    var srcHash = SurveyHelper.applyItemValueArrayCreateHash(src);
-    for (var i = 0; i < dest.length; i++) {
-      var ind = srcHash[dest[i].value];
-      dest[i].srcIndex = ind === undefined ? -1 : ind;
+    if (dest.length > src.length) {
+      dest.splice(src.length, dest.length - src.length);
     }
-    var insertIndex = 0;
-    for (var i = 0; i < src.length; i++) {
-      var ind = destHash[src[i].value];
-      if (ind === undefined) {
-        dest.splice(insertIndex, 0, src[i]);
-        insertIndex++;
-      } else {
-        insertIndex = ind + 1;
+    if (dest.length < src.length) {
+      var insertedArray = [];
+      for (var i = dest.length; i < src.length; i++) {
+        insertedArray.push(src[i]);
       }
+      dest.splice.apply(dest, [dest.length, 0].concat(insertedArray));
     }
-    for (var i = dest.length - 1; i >= 0; i--) {
-      if (dest[i].srcIndex === -1) {
-        dest.splice(i, 1);
-      } else {
-        if (dest[i].srcIndex > -1 && src[dest[i].srcIndex].hasText) {
-          dest[i].text = src[dest[i].srcIndex].text;
-        }
+    for (var i = 0; i < dest.length; i++) {
+      if (dest[i].value != src[i].value) {
+        dest[i].value = src[i].value;
       }
+      dest[i].text = src[i].hasText ? src[i].text : "";
     }
   }
-  private static applyItemValueArrayCreateHash(arr: Array<Survey.ItemValue>) {
-    var res = {};
-    for (var i = 0; i < arr.length; i++) {
-      res[arr[i].value] = i;
-    }
-    return res;
-  }
   public static disableSelectingObj(obj: Survey.Base) {
     obj["disableSelecting"] = true;
   }

tests/propertyEditors/propertyEditorsTests.ts

@@ -2491,4 +2491,13 @@ QUnit.test("SurveyHelper.applyItemValueArray", function (assert) {
     [1, { value: 2, text: "item 2" }, { value: 4, text: "item 4" }],
     7
   );
+  testSetFunc([1, 2, 2, 3, 4, 5, 6], [1, 2, 2, 3], 8);
+  testSetFunc([1, 2, 3, 4, 2, 5, 6], [1, 2, 3, 2], 9);
+  console.log(q2.toJSON());
+  testSetFunc(
+    [1, 2, 13, 14, 5, 6],
+    [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15],
+    10
+  );
+  console.log(q2.toJSON());
 });