/** * Validate data * * @param \Magento\Sales\Model\Order\Shipment\Comment $comment * @return array */ public function validate(Comment $comment) { $errors = []; $commentData = $comment->getData(); foreach ($this->required as $code => $label) { if (!$comment->hasData($code)) { $errors[$code] = sprintf('%s is a required field', $label); } elseif (empty($commentData[$code])) { $errors[$code] = sprintf('%s can not be empty', $label); } } return $errors; }