MAGETWO-45666: "Refresh cache" message is not displayed when changing category page layout

- Fixed wrong design change detection when default category layout is changed

Author: epamt

app/code/Magento/Catalog/Model/CategoryRepository.php

@@ -107,8 +107,6 @@ public function save(\Magento\Catalog\Api\Data\CategoryInterface $category)
             $parentCategory = $this->get($parentId, $storeId);
             $existingData['path'] = $parentCategory->getPath();
             $existingData['parent_id'] = $parentId;
-            $existingData['custom_apply_to_products'] = $existingData['custom_apply_to_products'] ?? 0;
-            $existingData['custom_use_parent_settings'] = $existingData['custom_use_parent_settings'] ?? 0;
         }
         $category->addData($existingData);
         try {

app/code/Magento/Catalog/Observer/InvalidateCacheOnCategoryDesignChange.php

@@ -15,12 +15,48 @@
  */
 class InvalidateCacheOnCategoryDesignChange implements ObserverInterface
 {
+    /**
+     * Default category design attributes values
+     */
+    private $defaultAttributeValues;
+
+    /**
+     * @var \Magento\Framework\App\Cache\TypeListInterface
+     */
+    private $cacheTypeList;
+
+    /**
+     * @var \Magento\Framework\App\Config\ScopeConfigInterface
+     */
+    private $scopeConfig;
+
     /**
      * @param \Magento\Framework\App\Cache\TypeListInterface $cacheTypeList
+     * @param \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
      */
-    public function __construct(\Magento\Framework\App\Cache\TypeListInterface $cacheTypeList)
-    {
+    public function __construct(
+        \Magento\Framework\App\Cache\TypeListInterface $cacheTypeList,
+        \Magento\Framework\App\Config\ScopeConfigInterface $scopeConfig
+    ) {
         $this->cacheTypeList = $cacheTypeList;
+        $this->scopeConfig = $scopeConfig;
+    }
+
+    /**
+     * Get default category design attribute values
+     *
+     * @return array
+     */
+    private function getDefaultAttributeValues()
+    {
+        return [
+            'custom_apply_to_products' => '0',
+            'custom_use_parent_settings' => '0',
+            'page_layout' => $this->scopeConfig->getValue(
+                'web/default_layouts/default_category_layout',
+                \Magento\Store\Model\ScopeInterface::SCOPE_STORE
+            )
+        ];
     }
 
     /**
@@ -33,7 +69,7 @@ public function execute(Observer $observer)
         $category = $observer->getEvent()->getEntity();
         if (!$category->isObjectNew()) {
             foreach ($category->getDesignAttributes() as $designAttribute) {
-                if ($category->dataHasChangedFor($designAttribute->getAttributeCode())) {
+                if ($this->isCategoryAttributeChanged($designAttribute->getAttributeCode(), $category)) {
                     $this->cacheTypeList->invalidate(
                         [
                             \Magento\PageCache\Model\Cache\Type::TYPE_IDENTIFIER,
@@ -45,4 +81,42 @@ public function execute(Observer $observer)
             }
         }
     }
+
+    /**
+     * Check if category attribute changed
+     *
+     * @param string $attributeCode
+     * @param \Magento\Catalog\Api\Data\CategoryInterface $category
+     * @return bool
+     */
+    private function isCategoryAttributeChanged($attributeCode, $category)
+    {
+        if (!array_key_exists($attributeCode, $category->getOrigData())) {
+            $defaultValue = $this->getDefaultAttributeValue($attributeCode);
+            if ($category->getData($attributeCode) !== $defaultValue) {
+                return true;
+            }
+        } else {
+            if ($category->dataHasChangedFor($attributeCode)) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
+    /**
+     * Get default category design attribute value
+     *
+     * @param string $attributeCode
+     * @return mixed|null
+     */
+    private function getDefaultAttributeValue($attributeCode)
+    {
+        if ($this->defaultAttributeValues === null) {
+            $this->defaultAttributeValues = $this->getDefaultAttributeValues();
+        }
+
+        return $this->defaultAttributeValues[$attributeCode] ?? null;
+    }
 }