MAGETWO-48286: "Create/Edit Customer" Admin forms do not support data validation without refreshing

Author: slavvka

app/code/Magento/Customer/Block/Adminhtml/Edit/Tab/Newsletter.php

@@ -133,6 +133,7 @@ public function isHidden()
      * Initialize the form.
      *
      * @return $this
+     * @SuppressWarnings(PHPMD.NPathComplexity)
      */
     public function initForm()
     {
@@ -148,7 +149,7 @@ public function initForm()
 
         $fieldset = $form->addFieldset('base_fieldset', ['legend' => __('Newsletter Information')]);
 
-        $subscriptionField = $fieldset->addField(
+        $fieldset->addField(
             'subscription',
             'checkbox',
             [
@@ -160,19 +161,13 @@ public function initForm()
         );
 
         if ($this->customerAccountManagement->isReadOnly($customerId)) {
-            $subscriptionField->setReadonly(true, true);
+            $form->getElement('subscription')->setReadonly(true, true);
         }
         $isSubscribed = $subscriber->isSubscribed();
         $form->setValues(['subscription' => $isSubscribed ? 'true' : 'false']);
-        $subscriptionField->setIsChecked($isSubscribed);
+        $form->getElement('subscription')->setIsChecked($isSubscribed);
 
-        $data = $this->_backendSession->getCustomerFormData();
-        if (!empty($data)) {
-            $dataCustomerId = isset($data['customer']['entity_id']) ? $data['customer']['entity_id'] : null;
-            if (isset($data['subscription']) && $dataCustomerId == $customerId) {
-                $subscriptionField->setIsChecked($data['subscription']);
-            }
-        }
+        $this->updateFromSession($form, $customerId);
 
         $changedDate = $this->getStatusChangedDate();
         if ($changedDate) {
@@ -191,6 +186,24 @@ public function initForm()
         return $this;
     }
 
+    /**
+     * Update form elements from session data
+     *
+     * @param \Magento\Framework\Data\Form $form
+     * @param int $customerId
+     * @return void
+     */
+    protected function updateFromSession(\Magento\Framework\Data\Form $form, $customerId)
+    {
+        $data = $this->_backendSession->getCustomerFormData();
+        if (!empty($data)) {
+            $dataCustomerId = isset($data['customer']['entity_id']) ? $data['customer']['entity_id'] : null;
+            if (isset($data['subscription']) && $dataCustomerId == $customerId) {
+                $form->getElement('subscription')->setIsChecked($data['subscription']);
+            }
+        }
+    }
+
     /**
      * Retrieve the date when the subscriber status changed.
      *

app/code/Magento/Customer/Model/Customer/DataProvider.php

@@ -19,6 +19,7 @@
 
 /**
  * Class DataProvider
+ * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
  */
 class DataProvider extends \Magento\Ui\DataProvider\AbstractDataProvider
 {

app/code/Magento/Customer/Test/Unit/Block/Adminhtml/Edit/Tab/NewsletterTest.php

@@ -3,6 +3,9 @@
  * Copyright © 2015 Magento. All rights reserved.
  * See COPYING.txt for license details.
  */
+
+// @codingStandardsIgnoreFile
+
 namespace Magento\Customer\Test\Unit\Block\Adminhtml\Edit\Tab;
 
 use Magento\Backend\Model\Session;
@@ -129,6 +132,14 @@ public function testInitForm()
 
         $this->backendSessionMock->expects($this->once())->method('getCustomerFormData')->willReturn(null);
 
+        $formMock->expects($this->once())
+            ->method('getElement')
+            ->willReturnMap(
+                [
+                    ['subscription', $elementMock],
+                ]
+            );
+
         $elementMock->expects($this->once())
             ->method('setIsChecked')
             ->with(true);
@@ -178,6 +189,14 @@ public function testInitFormWithCustomerFormData()
                 'subscription' => true,
             ]);
 
+        $formMock->expects($this->exactly(2))
+            ->method('getElement')
+            ->willReturnMap(
+                [
+                    ['subscription', $elementMock],
+                ]
+            );
+
         $elementMock->expects($this->exactly(2))
             ->method('setIsChecked')
             ->willReturnMap(