public function submissionSaveData(array $formData)
    {
        // remove empty values
        $formData = array_filter($formData);

        // get array of files to upload
        $files = [];
        foreach ($formData as $field => $value) {
            if (Request::hasFile($field)) {
                $files[$field] = Request::file($field);
                unset($formData[$field]);
            }
        }

        // save form submission
        $form_submission = new FormSubmission;
        $form_submission->form_block_id = $this->_block->id;
        $form_submission->content = serialize($formData);
        $form_submission->sent = 0;
        $form_submission->from_page_id = PageBuilder::pageId();
        $form_submission->save();
        $form_submission->uploadFiles($files);
        return $form_submission;
    }