yii2如何防止xss攻击

 /*  防sql注入,xss攻击  (1)*/
    function actionClean($str)
    {
        $str=trim($str);
        $str=strip_tags($str);
        $str=stripslashes($str);
        $str=addslashes($str);
        $str=rawurldecode($str);
        $str=quotemeta($str);
        $str=htmlspecialchars($str);
        //去除特殊字符
        $str=preg_replace("//|~|!|@|#|\$|%|^|&|*|(|)|_|+|{|}|:|<|>|?|[|]|,|.|/|;|'|`|-|=|\||/", "" , $str);
        $str=preg_replace("/s/", "", $str);//去除空格、换行符、制表符
        return $str;
    }


    //防止sql注入。xss攻击(1)
    public function actionFilterArr($arr)
    {
        if(is_array($arr)){
            foreach($arr as $k => $v){
                $arr[$k] = $this->actionFilterWords($v);
            }
        }else{
            $arr = $this->actionFilterWords($arr);
        }
        return $arr;
    }


    //防止xss攻击
   public function actionFilterWords($str)
    {
        $farr = array(
            "/<(\/?)(script|i?frame|style|html|body|title|link|meta|object|\?|\%)([^>]*?)>/isU",
            "/(<[^>]*)on[a-zA-Z]+s*=([^>]*>)/isU",
            "/select|insert|update|delete|drop|'|/*|*|+|-|"|../|./|union|into|load_file|outfile|dump/is"
        );
        $str = preg_replace($farr,'',$str);
        return $str;
    }

    //防止sql注入,xss攻击(2)
    public function post_check($post) {
      if(!get_magic_quotes_gpc()) {
          foreach($post as $key=>$val){
             $post[$key]  = addslashes($val);
          }
        }
      foreach($post as $key=>$val){
        //把"_"过滤掉
        $post[$key] = str_replace("_", "_", $val);
        //把"%"过滤掉
        $post[$key] = str_replace("%", "%", $val); //sql注入
        $post[$key] = nl2br($val);
        //转换html
        $post[$key] = htmlspecialchars($val); //xss攻击
      }
      return $post;
  }