magento/magento2-login-as-customer#144: Banner is not shown on Category page if Disable Page Cache For Admin User = No.

Author: engcom-Foxtrot

app/code/Magento/LoginAsCustomerFrontendUi/Plugin/KeepLoginAsCustomerSessionDataPlugin.php

@@ -0,0 +1,71 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+
+namespace Magento\LoginAsCustomerFrontendUi\Plugin;
+
+use Magento\Framework\Session\SessionManagerInterface;
+use Magento\LoginAsCustomerApi\Api\ConfigInterface;
+use Magento\LoginAsCustomerApi\Api\GetLoggedAsCustomerAdminIdInterface;
+use Magento\LoginAsCustomerApi\Api\SetLoggedAsCustomerAdminIdInterface;
+
+/**
+ * Keep adminId in customer session if session data is cleared.
+ */
+class KeepLoginAsCustomerSessionDataPlugin
+{
+    /**
+     * @var ConfigInterface
+     */
+    private $config;
+
+    /**
+     * @var GetLoggedAsCustomerAdminIdInterface
+     */
+    private $getLoggedAsCustomerAdminId;
+
+    /**
+     * @var SetLoggedAsCustomerAdminIdInterface
+     */
+    private $setLoggedAsCustomerAdminId;
+
+    /**
+     * @param ConfigInterface $config
+     * @param GetLoggedAsCustomerAdminIdInterface $getLoggedAsCustomerAdminId
+     * @param SetLoggedAsCustomerAdminIdInterface $setLoggedAsCustomerAdminId
+     */
+    public function __construct(
+        ConfigInterface $config,
+        GetLoggedAsCustomerAdminIdInterface $getLoggedAsCustomerAdminId,
+        SetLoggedAsCustomerAdminIdInterface $setLoggedAsCustomerAdminId
+    ) {
+        $this->config = $config;
+        $this->getLoggedAsCustomerAdminId = $getLoggedAsCustomerAdminId;
+        $this->setLoggedAsCustomerAdminId = $setLoggedAsCustomerAdminId;
+    }
+
+    /**
+     * Keep adminId in customer session if session data is cleared.
+     *
+     * @param SessionManagerInterface $subject
+     * @param \Closure $proceed
+     * @return SessionManagerInterface
+     *
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    public function aroundClearStorage(
+        SessionManagerInterface $subject,
+        \Closure $proceed
+    ): SessionManagerInterface {
+        $enabled = $this->config->isEnabled();
+        $adminId = $enabled ? $this->getLoggedAsCustomerAdminId->execute() : null;
+        $result = $proceed();
+        if ($enabled && $adminId) {
+            $this->setLoggedAsCustomerAdminId->execute($adminId);
+        }
+
+        return $result;
+    }
+}

app/code/Magento/LoginAsCustomerFrontendUi/etc/frontend/di.xml

@@ -17,4 +17,8 @@
         <plugin name="invalidate_expired_session_plugin"
                 type="Magento\LoginAsCustomerFrontendUi\Plugin\InvalidateExpiredSessionPlugin"/>
     </type>
+    <type name="Magento\Framework\Session\SessionManagerInterface">
+        <plugin name="keep_login_as_customer_session_data"
+                type="Magento\LoginAsCustomerFrontendUi\Plugin\KeepLoginAsCustomerSessionDataPlugin"/>
+    </type>
 </config>