MAGETWO-58651: Refactor saveFormHandler() method

Author: Sergey Semenov

app/code/Magento/ConfigurableProduct/view/adminhtml/web/js/variations/variations.js

@@ -383,12 +383,7 @@ define([
          * Chose action for the form save button
          */
         saveFormHandler: function () {
-            this.source.data['configurable-matrix-serialized'] =
-                JSON.stringify(this.source.data['configurable-matrix']);
-            delete this.source.data['configurable-matrix'];
-            this.source.data['associated_product_ids_serialized'] =
-                JSON.stringify(this.source.data['associated_product_ids']);
-            delete this.source.data['associated_product_ids'];
+            this.serializeData();
 
             if (this.checkForNewAttributes()) {
                 this.formSaveParams = arguments;
@@ -398,6 +393,31 @@ define([
             }
         },
 
+        /**
+         * Serialize data for specific form fields
+         *
+         * Get data from outdated fields, serialize it and produce new form fields.
+         *
+         * Outdated fields:
+         *   - configurable-matrix;
+         *   - associated_product_ids.
+         *
+         * New fields:
+         *   - configurable-matrix-serialized;
+         *   - associated_product_ids_serialized.
+         */
+        serializeData: function () {
+            this.source.data['configurable-matrix-serialized'] =
+                JSON.stringify(this.source.data['configurable-matrix']);
+
+            delete this.source.data['configurable-matrix'];
+
+            this.source.data['associated_product_ids_serialized'] =
+                JSON.stringify(this.source.data['associated_product_ids']);
+
+            delete this.source.data['associated_product_ids'];
+        },
+
         /**
          * Check for newly added attributes
          * @returns {Boolean}