Command::checkRequiredFields

public function checkRequiredFields(UserFieldCollection $userFieldCollection): Result
{
	$result = new Result();

	foreach($userFieldCollection as $userField)
	{
		if($userField->isMandatory() && $this->item->isEmptyUserFieldValue($userField->getName()))
		{
			$result->addError($this->getMandatoryFieldError($userField->getTitle()));
		}
	}

	return $result;
}