MC-2379: CMS content containing widget directives is not updated when the linked widget directive entities are updated

- Implemented IdentityInterface for widget block model

Author: nathanjosiah

app/code/Magento/Cms/Block/Widget/Block.php

@@ -3,14 +3,23 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+
+declare(strict_types=1);
+
 namespace Magento\Cms\Block\Widget;
 
+use Magento\Framework\DataObject\IdentityInterface;
+use Magento\Framework\Exception\LocalizedException;
+use Magento\Framework\Exception\NoSuchEntityException;
+use Magento\Widget\Block\BlockInterface;
+use Magento\Cms\Model\Block as CmsBlock;
+
 /**
  * Cms Static Block Widget
  *
- * @author     Magento Core Team <core@magentocommerce.com>
+ * @author Magento Core Team <core@magentocommerce.com>
  */
-class Block extends \Magento\Framework\View\Element\Template implements \Magento\Widget\Block\BlockInterface
+class Block extends \Magento\Framework\View\Element\Template implements BlockInterface, IdentityInterface
 {
     /**
      * @var \Magento\Cms\Model\Template\FilterProvider
@@ -31,6 +40,11 @@ class Block extends \Magento\Framework\View\Element\Template implements \Magento
      */
     protected $_blockFactory;
 
+    /**
+     * @var CmsBlock
+     */
+    private $block;
+
     /**
      * @param \Magento\Framework\View\Element\Template\Context $context
      * @param \Magento\Cms\Model\Template\FilterProvider $filterProvider
@@ -65,19 +79,61 @@ protected function _beforeToHtml()
         }
         self::$_widgetUsageMap[$blockHash] = true;
 
-        if ($blockId) {
-            $storeId = $this->_storeManager->getStore()->getId();
-            /** @var \Magento\Cms\Model\Block $block */
-            $block = $this->_blockFactory->create();
-            $block->setStoreId($storeId)->load($blockId);
-            if ($block->isActive()) {
+        $block = $this->getBlock();
+
+        if ($block && $block->isActive()) {
+            try {
+                $storeId = $this->_storeManager->getStore()->getId();
                 $this->setText(
                     $this->_filterProvider->getBlockFilter()->setStoreId($storeId)->filter($block->getContent())
                 );
+            } catch (NoSuchEntityException $e) {
             }
         }
-
         unset(self::$_widgetUsageMap[$blockHash]);
         return $this;
     }
+
+    /**
+     * Get identities of the Cms Block
+     *
+     * @return array
+     */
+    public function getIdentities()
+    {
+        $block = $this->getBlock();
+
+        if ($block) {
+            return $block->getIdentities();
+        }
+
+        return [];
+    }
+
+    /**
+     * @return CmsBlock|null
+     */
+    private function getBlock(): ?CmsBlock
+    {
+        if ($this->block) {
+            return $this->block;
+        }
+
+        $blockId = $this->getData('block_id');
+
+        if ($blockId) {
+            try {
+                $storeId = $this->_storeManager->getStore()->getId();
+                /** @var \Magento\Cms\Model\Block $block */
+                $block = $this->_blockFactory->create();
+                $block->setStoreId($storeId)->load($blockId);
+                $this->block = $block;
+
+                return $block;
+            } catch (NoSuchEntityException $e) {
+            }
+        }
+
+        return null;
+    }
 }