FormInterceptor.php

<?php 

namespace Lunetics\AppBundle\Form\Response;

class FormInterceptor {
 public function getFormErrorsToJson(Form $form)
    {
        $errors = array();
        $translator = $this->get('translator');
        
        if (count($form->getErrors())) {
            foreach ($form->getErrors() as $error) {
                $errors[$form->getName()]['errors'][] = $translator->trans(
                    $error->getMessageTemplate(), 
                    $error->getMessageParameters(),
                    $this->getValidatorTranslationDomain()
                );
            }
        }
        if ($form->count()) {
            foreach ($form->all() as $child) {
                if ($child->count()) {
                    if ($childErrors = $this->getFormErrorsForJson($child)) {
                        $errors[$form->getName()]['childErrors'] = array_merge_recursive(
                            isset($errors[$form->getName()]['childErrors'])
                                ? $errors[$form->getName()]['childErrors']
                                : array(),
                            $childErrors
                        );
                    }
                } else if (count($child->getErrors())) {
                    $translationDomain = $this->getValidatorTranslationDomain();
                    $errors[$form->getName()]['childErrors'][$child->getName()] = array_map(
                        function($error) use ($translator, $translationDomain) {
                            return $translator->trans(
                                $error->getMessageTemplate(),
                                $error->getMessageParameters(),
                                $translationDomain
                            );
                        }, $child->getErrors()
                    );
                }
            }
        }
        return $errors;
}