在jQuery的延迟对象中抛出错误 [英] Throwing an Error in jQuery's Deferred object

问题描述

我有一个 $。ajax 承诺，并希望检查我的（语法有效的）响应是否包含一个错误，触发被拒绝的状态在这种情况。

I have an $.ajax promise and want to check whether my (syntactically valid) response contains an error, triggering the rejected status in that case.

我已经与我自己的承诺库轻松处理这些任务。我不喜欢jQuery的承诺（缓存）实现与其 Deferred object ，可能忽视了一些东西，因为我很少使用它。我想要走的路上只是使用 .then（） ，这似乎相当复杂：

I have worked with my own promise library which deals such tasks easily. I do not really like jQuery's Promise (cache) implementation with its Deferred object and may have overlooked something, because I seldom use it. I think the way to go is just using .then(), which seems to be rather complicated:

return $.ajax(...).then(function success(response) {
    var problem = hasError(response);
    if (problem) {
        var error = new $.Deferred;
        error.reject(problem);
        return error;
    } else
        return response;
});

这应该返回在网络错误或响应问题的情况下被拒绝的承诺。但是返回被拒绝的延期真的是[唯一|最好|最短]的方式吗？

This should return a promise which is rejected in case of network errors or problems with the response. But is returning a rejected deferred really the [only|best|shortest] way to go?

我还将提供如何处理这种错误抛出响应的帮助处理程序在ajax选项中，我找不到关于他们的良好文档。

I also would appriciate help on how to deal with such "error-throwing response handlers" in the ajax options themselfes, I could not find good documentation about them.

免责声明：不，我不能更改服务器响应。问题检测方法是同步的。我不想使用其他库，我对jQuery解决这个问题的方式特别感兴趣。

Disclaimer: No, I cant change the server responses. The problem-detecting method is synchronous. I don't want to use other libraries, I'm particularly interested in the way jQuery solves this.

推荐答案

现在更新为jQuery 1.8 +

解决此问题的最简单的方法是运行 $。ajax 通过 .then 根据数据的成功或失败进行过滤。

The easiest way to tackle this is to run the response of $.ajax through .then to filter based on success or failure of the data.

$.ajax()
    .then(function (response) {
        return $.Deferred(function (deferred) {
            var problem = hasError(response);

            if (problem) {
                return deferred.reject(problem)
            }

            deferred.resolve(response);
        }).promise();
    });

然后，您可以将这个新承诺退回到任何调用代码将消耗这一点：

You could then return this new promise to whatever calling code would consume this:

var request = function () {
    return $.ajax()
        .then(function (response) {
            return $.Deferred(function (deferred) {
                var problem = hasError(response);

                if (problem) {
                    return deferred.reject(problem)
                }

                deferred.resolve(response);
            }).promise();
        });
};

request()
    .done(function (response) {
        // handle success
    })
    .fail(function (problem) {
        // handle failure
    });

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