关于jq ajax的使用

//前台ajax

    var apply_info = new FormData(document.getElementById("apply_info"));
    $.ajax({
        url:"/experts/apply",
        type:"POST",
        data:apply_info,
        cache: false,
        processData: false,
        contentType: false,
        success:function(data){    
            var datajson = JSON.parse(data);        
            if (datajson.status == 'error') {
                alert("温馨提示:" + datajson.msg); 
            }

            if (datajson.status == 'success') {
                $(location).attr('href', '/experts/result' );
            }       

            },
        error:function(e){
            alert("请求失败,如果不是已经提交过请稍后再试");
        }
    });  

//后台处理

  //TODO判断是否是博客专家
        $this->load->model('repository/BlogRepository');
        $blog = $this->BlogRepository->getBlogByName($user_info->userName);
        if ($blog->Flag) {
            echo json_encode(['status' => 'error', 'msg' => '请已经是博客专家了哦']);
            return;
        }