Symfony\Component\Form\Extension\DataCollector\FormDataExtractor::extractSubmittedData PHP Method

    public function extractSubmittedData(FormInterface $form)
    {
        $data = array(
            'submitted_data' => array(
                'norm' => $form->getNormData(),
            ),
            'errors' => array(),
        );

        if ($form->getViewData() !== $form->getNormData()) {
            $data['submitted_data']['view'] = $form->getViewData();
        }

        if ($form->getData() !== $form->getNormData()) {
            $data['submitted_data']['model'] = $form->getData();
        }

        foreach ($form->getErrors() as $error) {
            $errorData = array(
                'message' => $error->getMessage(),
                'origin' => is_object($error->getOrigin())
                    ? spl_object_hash($error->getOrigin())
                    : null,
                'trace' => array(),
            );

            $cause = $error->getCause();

            while (null !== $cause) {
                if ($cause instanceof ConstraintViolationInterface) {
                    $errorData['trace'][] = $cause;
                    $cause = method_exists($cause, 'getCause') ? $cause->getCause() : null;

                    continue;
                }

                if ($cause instanceof \Exception) {
                    $errorData['trace'][] = $cause;
                    $cause = $cause->getPrevious();

                    continue;
                }

                $errorData['trace'][] = $cause;

                break;
            }

            $data['errors'][] = $errorData;
        }

        $data['synchronized'] = $form->isSynchronized();

        return $data;
    }

    /**
     * {@inheritdoc}
     */
    public function collectSubmittedData(FormInterface $form)
    {
        $hash = spl_object_hash($form);

        if (!isset($this->dataByForm[$hash])) {
            // field was created by form event
            $this->collectConfiguration($form);
            $this->collectDefaultData($form);
        }

        $this->dataByForm[$hash] = array_replace(
            $this->dataByForm[$hash],
            $this->dataExtractor->extractSubmittedData($form)
        );

        // Count errors
        if (isset($this->dataByForm[$hash]['errors'])) {
            $this->data['nb_errors'] += count($this->dataByForm[$hash]['errors']);
        }

        foreach ($form as $child) {
            $this->collectSubmittedData($child);

            // Expand current form if there are children with errors
            if (empty($this->dataByForm[$hash]['has_children_error'])) {
                $childData = $this->dataByForm[spl_object_hash($child)];
                $this->dataByForm[$hash]['has_children_error'] = !empty($childData['has_children_error']) || !empty($childData['errors']);
            }
        }
    }