Symfony 4 Form validation trait, useful for getting errors from form validation and constraints.

FormValidationTrait.php

<?php

namespace App\Form\Api;

use Symfony\Component\Form\FormInterface;
use Symfony\Component\Validator\ConstraintViolation;

trait FormValidationTrait
{
    private function getErrorsFromForm(FormInterface $form)
    {
        $errors = array();

        foreach ($form->getErrors() as $error) {
            $errors[$error->getCause()->getPropertyPath()] = [
                'message' => $error->getMessage(),
                'severity' => $this->checkConstraintPayloadSeverity($error->getCause()),
                'code' => $this->checkConstraintPayloadCode($error->getCause())
            ];
        }

        foreach ($form->all() as $childForm) {

            if ($childForm instanceof FormInterface) {
                if ($childErrors = $this->getErrorsFromForm($childForm)) {
                    $errors = array_merge($errors, $this->getErrorsFromForm($childForm));
                }
            }
        }

        return $errors;
    }

    private function checkConstraintPayloadSeverity(ConstraintViolation $error)
    {
        $constraint = $error->getConstraint();

        return $constraint->payload['severity'] ?? null;
    }

    private function checkConstraintPayloadCode(ConstraintViolation $error)
    {
        $constraint = $error->getConstraint();

        return $constraint->payload['code'] ?? null;
    }

    private function isAllowedToContinue(array $errorCollection)
    {
        if ($errorCollection == null) {
            return true;
        }

        dump($errorCollection);
        die();

        foreach ($errorCollection as $field => $collection) {

            foreach ($collection as $payload) {

                $severity = $payload['severity'] ?? null;

                switch ($severity) {
                    case "critical":
                        return false;
                        break;
                    case "warning":
                        $response = true;
                        break;
                    case "notice":
                        $response = true;
                        break;
                    default:
                        $response = true;
                        break;
                }

            }
        }

        return $response;
    }

    private function simplifyErrors($errorsCollection)
    {
        $simpleErrors = [];

        foreach ($errorsCollection as $field => $collection) {

            $message = '';

            foreach ($collection as $payload) {

                $message = $payload['message'] ?? '';
            }

            $simpleErrors[$field] = $message;
        }

        return $simpleErrors;
    }
}