UserMailRequiredValidator.php in Drupal 10        
                          
                  
                        
  
  
  
  
File
  core/modules/user/src/Plugin/Validation/Constraint/UserMailRequiredValidator.php
  
    View source  
  <?php
namespace Drupal\user\Plugin\Validation\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Symfony\Component\Validator\Constraint;
class UserMailRequiredValidator extends ConstraintValidator {
  
  public function validate($items, Constraint $constraint) {
    
    
    $account = $items
      ->getEntity();
    if (!isset($account)) {
      return;
    }
    $existing_value = NULL;
    
    if (!$account
      ->isNew()) {
      $account_unchanged = \Drupal::entityTypeManager()
        ->getStorage('user')
        ->loadUnchanged($account
        ->id());
      $existing_value = $account_unchanged
        ->getEmail();
    }
    $required = !(!$existing_value && \Drupal::currentUser()
      ->hasPermission('administer users'));
    if ($required && (!isset($items) || $items
      ->isEmpty())) {
      $this->context
        ->addViolation($constraint->message, [
        '@name' => $account
          ->getFieldDefinition('mail')
          ->getLabel(),
      ]);
    }
  }
}