public function submit($postContent)
    {
        if (!empty($postContent['alt']) || !empty($postContent['source'])) {
            $imageData = $this->_defaultData('');
            $imageData->title = !empty($postContent['alt']) ? $postContent['alt'] : '';
            $imageData->file = !empty($postContent['source']) ? $postContent['source'] : '';
        } else {
            $imageData = '';
        }
        return $this->save($imageData ? serialize($imageData) : '');
    }