这是预期的错误是从我的预期，甚至在code提出自己的服务器。例如，当用户试图执行为此，他没有足够的权限的行动，我会提高 PermissionError （自定义异常）与描述错误的消息。

An expected error is one from the server that I anticipated or even raised by myself in the code. For example, when a user attempts to perform an action for which he has no sufficient privilege, I would raise PermissionError (a custom Exception) with a message describing the error.

我一直在寻找一个很好的方式来处理预期的错误对AJAX的情况。唯一的要求是要能够显示错误信息给用户，因为我要保持我的用户在什么事情上的循环。

I have been searching for a good way to handle expected error for AJAX situation. The only requirement is to be able to display the error message to the user, as I want to keep my users in the loop of what's going on.

我目前的做法是包装错误消息成JSON对象并将其发送回客户端

My current approach is packaging the error message into a JSON object and send it back to the client-end

var ajaxResponse = $.ajax({
    ....        
});

ajaxResponse.done(function(jsonObj) {
    if (jsonObj.success) {
        /* no error, do something */    
    }
    else {
        /* expected error returned, display jsonObj.error to user */
    }
});

ajaxResponse.fail(function(jqXHR, textStatus, errorThrown) {
    /* unexpected error returned */
});

我心目中的另一种方法，这我不知道。而不是包装预期的错误的消息成JSON对象，在我的Django code基本上，我将返回的Htt presponse（CONTENT =没有足够的权限，状态= 403）。客户端的jQuery会被修改如下所示：

I have another approach in mind, which I am not sure about. Basically, instead of packaging the message of expected error into a JSON object, in my django code I would return HttpResponse(content="no sufficient privilege", status=403). The client-end jQuery would get modified like the following:

ajaxResponse.done(function(response_data) {
    /* no error, do something */
});

ajaxResponse.fail(function(jqXHR, textStatus, errorThrown) {
    /* both expected and unexpected error would end up here.
     * It's an expected error when error code is 403 and 
     * jqXHR.responseText would give me the error message to 
     * display to the user.
     */
});

我喜欢第二种方法组中的所有错误，预期的或意外的，在一个地方。但后来，我有一种感觉，HTTP状态code不应该用这种方式。不管怎么说，我想知道哪一个是正确的道路要走。如果没有，请分享你会做什么。

I like how the second approach groups all errors, expected or unexpected, in one place. But then, I have a feeling that http status code shouldn't be used this way. Anyways, I want to know which one is the right way to go. If neither, please share what you would do.

推荐答案

有这样一个全局配置 -

Have a global configuration like this -

$.ajaxSetup({

     error: function(xhr){
         /* Do something with xhr.responseText */
         window.status='Your error message goes here';
     }

});