Form/Handler.php
public function handle(FormInterface $form, FormConfigurationInterface $configuration)
    {
        if (!$form->isValid()) {
            return false;
        }

        $mediaIds = $this->uploadMedia($form, $configuration);
        $this->mapMediaIds($form->getData(), $mediaIds);
        $this->save($form, $configuration);
        $this->sendMails($form, $configuration);

        return true;
    }
public function handle(FormInterface $form, FormConfigurationInterface $configuration)
    {
        if (!$form->isValid()) {
            return false;
        }

        $mediaIds = $this->uploadMedia($form, $configuration);
        $this->mapMediaIds($form->getData(), $mediaIds);
        $this->save($form, $configuration);
        $this->sendMails($form, $configuration);

        return true;
    }
Handle form.

@param FormInterface $form
@param FormConfigurationInterface $configuration

@return bool