ACP2E-711: "Invalid Form Key. Please refresh the page." error occurs when changing the product limit in categories

- Updated solution to pass functional test cases, and run solution only when the setting is set.

Author: Mohan Ahuja

app/code/Magento/PageCache/ViewModel/FormKeyProvider.php

@@ -7,6 +7,7 @@
 
 namespace Magento\PageCache\ViewModel;
 
+use Magento\Framework\App\Config\ScopeConfigInterface;
 use Magento\Framework\View\Element\Block\ArgumentInterface;
 use Magento\PageCache\Model\Config;
 
@@ -15,18 +16,31 @@
  */
 class FormKeyProvider implements ArgumentInterface
 {
+    /**
+     * XML PATH to enable/disable saving toolbar parameters to session
+     */
+    const XML_PATH_CATALOG_REMEMBER_PAGINATION = 'catalog/frontend/remember_pagination';
+
     /**
      * @var Config
      */
-    private $config;
+    private Config $config;
+
+    /**
+     * @var ScopeConfigInterface object
+     */
+    private ScopeConfigInterface $scopeConfig;
 
     /**
      * @param Config $config
+     * @param ScopeConfigInterface $scopeConfig
      */
     public function __construct(
-        Config $config
+        Config $config,
+        ScopeConfigInterface $scopeConfig
     ) {
         $this->config = $config;
+        $this->scopeConfig = $scopeConfig;
     }
 
     /**
@@ -38,4 +52,9 @@ public function isFullPageCacheEnabled(): bool
     {
         return $this->config->isEnabled();
     }
+
+    public function isPaginationCacheEnabled(): bool
+    {
+        return $this->scopeConfig->isSetFlag(self::XML_PATH_CATALOG_REMEMBER_PAGINATION);
+    }
 }

app/code/Magento/PageCache/view/frontend/templates/form_key_provider.phtml

@@ -7,7 +7,9 @@ if ($block->getFormKeyProvider()->isFullPageCacheEnabled()): ?>
     <script type="text/x-magento-init">
         {
             "*": {
-                "Magento_PageCache/js/form-key-provider": {}
+                "Magento_PageCache/js/form-key-provider": {
+                    "isPaginationCacheEnabled": <?= /* @noEscape */ $block->getFormKeyProvider()->isPaginationCacheEnabled() ?>
+                }
             }
         }
     </script>

app/code/Magento/PageCache/view/frontend/web/js/form-key-provider.js

@@ -5,7 +5,7 @@
 define(function () {
     'use strict';
 
-    return function () {
+    return function (settings) {
         var formKey,
             inputElements,
             inputSelector = 'input[name="form_key"]';
@@ -82,8 +82,13 @@ define(function () {
         function initFormKey() {
             formKey = getFormKeyCookie();
 
+            if (settings.isPaginationCacheEnabled && !formKey) {
+                formKey = getFormKeyFromUI();
+                setFormKeyCookie(formKey);
+            }
+
             if (!formKey) {
-                formKey = getFormKeyFromUI() || generateFormKeyString();
+                formKey = generateFormKeyString();
                 setFormKeyCookie(formKey);
             }
             inputElements = document.querySelectorAll(inputSelector);