inanzzz | Handling form errors manually with a service class in symfony

Example below shows us how to handle form errors manually with a service class. The problem with this approach is, it won't auto-fill form fields if an error occurs so you need to handle it yourself too.

Service definition

# sport/src/Football/FrontendBundle/Resources/config/services.yml
services:
    football_frontend.service.form_error:
        class: Football\FrontendBundle\Service\FormErrorService

Error service class

# src/Football/FrontendBundle/Service/FormErrorServiceInterface.php
namespace Football\FrontendBundle\Service;

use Symfony\Component\Form\FormInterface;

interface FormErrorServiceInterface
{
    public function getErrors(FormInterface $form);
}

# sport/src/Football/FrontendBundle/Service/FormErrorService.php
namespace Football\FrontendBundle\Service;

use Symfony\Component\Form\FormInterface;

class FormErrorService implements FormErrorServiceInterface
{
    public function getErrors(FormInterface $form)
    {
        $errors = array();

        // This part gets global form errors (like csrf token error)
        foreach ($form->getErrors() as $error) {
            $errors[] = $error->getMessage();
        }

        // This part gets form field errors
        foreach ($form->all() as $child) {
            if (! $child->isValid()) {
                $options = $child->getConfig()->getOptions();
                $field = $options['label'] ? $options['label'] : ucwords($child->getName());
                // Implode because there can be more than one field errors
                $errors[strtolower($field)] = implode('; ', $this->getErrors($child));
            }
        }

        return $errors;
    }
}

Controller part

class CountryController extends Controller
{
    public function createAction(Request $request)
    {
        // .....

        if ($form->isValid() !== true) {
            $errors = $this->get('football_frontend.service.form_error')->getErrors($form);

            return $this->render(
                'FootballTeamBundle:Create:country.html.twig',
                [
                    'form' => $form->createView(),
                    'errors' => $errors
                ]
            );
        }

        // .....
    }
}

Twig template part

{% if errors is defined and errors is iterable %}
    <div class="global-form-errors">
        <ul>
            {% for field, message in errors %}
                <li>{{ message }}</li>
            {% endfor %}
        </ul>
    </div>
{% endif %}