PHP后台处理富文本编辑器内容时，为媒体标签的链接加上域名

适用于提交的富文本内容的媒体标签的链接不带域名时

/**
 * @notes: 设置内容图片域名
 * @param $content
 */
function add_content_domain($content)
{
    if(empty($content)){
        return '';
    }
    $imgPreg   = '/(<img .*?src=")[^https|^http](.*?)(".*?>)/is';
    $videoPreg = '/(<video .*?src=")[^https|^http](.*?)(".*?>)/is';
    $audioPreg = '/(<audio .*?src=")[^https|^http](.*?)(".*?>)/is';
    $domain    = request()->domain();
    $content   = preg_replace($imgPreg, "\${1}$domain\${2}\${3}", $content);
    $content   = preg_replace($videoPreg, "\${1}$domain\${2}\${3}", $content);
    return preg_replace($audioPreg, "\${1}$domain\${2}\${3}", $content);
}