jQuery的：处理回退失败的AJAX请求 [英] jQuery: Handle fallback for failed AJAX Request

问题描述

jQuery的可以提供一个备用失败的AJAX调用？这是我的尝试：

Can jQuery provide a fallback for failed AJAX calls? This is my try:

function update() {
    var requestOK = false;

    $.getJSON(url, function(){
        alert('request successful');
        requestOK = true;
    });

    if (!requestOK) {
        alert('request failed');
    }
}

不幸的是，即使$ .getJSON（）方法的回调函数被调用时，我得到请求失败的消息，前回调函数有机会设置requestOK变量。我认为这是因为code并行运行。有没有一种方法来处理这​​种情况？我想到了链接或等待AJAX​​请求，包括它的回调函数的一些方法。但如何？有谁知道该怎么做？

Unfortunately, even if the callback function of the $.getJSON() method is called, i get the message 'request failed', before the callback function has the opportunity to set the requestOK variable. I think it's because the code runs in parallel. Is there a way to handle such situations? I thought about chaining or some way of waiting for the AJAX request, including its callback function. But how? Does anyone know how to do that?

推荐答案

您需要可以使用较低的水平 $就打电话，或 ajaxError 的功能。在这里，它与$阿贾克斯方式：

You will need to either use the lower level $.ajax call, or the ajaxError function. Here it is with the $.ajax method:

function update() {
  $.ajax({
    type: 'GET',
    dataType: 'json',
    url: url,
    timeout: 5000,
    success: function(data, textStatus ){
       alert('request successful');
    },
    error: function(xhr, textStatus, errorThrown){
       alert('request failed');
    }
  });
}

修改我添加了一个暂停到 $。阿贾克斯通话，并将其设置为5秒。

EDIT I added a timeout to the $.ajax call and set it to five seconds.

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