使用数组的 AJAX 承诺 [英] AJAX Promises using Array

问题描述

我正在尝试使用 Promise 进行几次 AJAX 调用(假设为 2 个).基本上我希望能够将两个响应合并在一起，对它们作为一个整体进行一些分析，然后吐出一个响应.现在，我有:

I'm trying to make several AJAX calls (let's say 2) using promises. Basically I want to be able to merge the two responses together, perform some analysis on them as a whole, then spit out a response. Right now, I have:

var responseArray = [];
for (var i=0; i<letsSayTwo; i++) {
  responseArray.push(someAjaxCall(data));
};
responseArray.done(function(response) {
  var spit = someAnalysis(response);
  console.log(spit);
});
responseArray.fail(function(response) {
  console.log('fail');
});

就目前而言，我在控制台中收到未捕获的类型错误:对象 [对象数组] 没有方法‘完成’"错误.我认为我不能使用这种方法是否正确?我研究了使用以下代码 (http://gregfranko.com/blog/jquery-best-practices/) 但我似乎无法得到我需要的回应.

As it stands, I'm getting an "Uncaught TypeError: Object [object Array] has no method 'done'" error in console. Am I correct in thinking that I can't use this method? I looked into using the following bit of code from (http://gregfranko.com/blog/jquery-best-practices/) but I can't seem to get the response that I need.

$.when.apply(this, responseArray).then(function(response) {
  console.log(response);
});

相反，我得到的是 [response, "success", response] 其中第一个响应是 AJAX 调用之一的正确返回响应，最后一个响应是实际调用本身.我应该如何从两个 AJAX 调用中获得正确的响应?

Instead, what I get is [response, "success", response] where the first response is the correct return response for one of the AJAX calls and the last response is the actual call itself. How should I go about getting the correct responses from both AJAX calls??

我希望这一切都有意义.谢谢！

I hope this all makes sense. Thanks!

推荐答案

就目前而言，我在控制台中收到 Uncaught TypeError: Object [object Array] has no method 'done' 错误.我认为我不能使用这种方法是否正确?

As it stands, I'm getting an Uncaught TypeError: Object [object Array] has no method 'done' error in console. Am I correct in thinking that I can't use this method?

不是在数组上，是的.您只能在 Promise 和 Deferred 对象上调用此方法，例如由 $.when.apply(this, responseArray)

Not on arrays, yes. You can call this method only on Promise and Deferred objects, like the one produced by $.when.apply(this, responseArray)

...但我似乎无法得到我需要的回应.相反，我得到的是 [response, "success", response] 其中第一个响应是一个 AJAX 调用的正确返回响应，最后一个响应是实际调用本身.

… but I can't seem to get the response that I need. Instead, what I get is [response, "success", response] where the first response is the correct return response for one of the AJAX calls and the last response is the actual call itself.

如 $.when 文档中所述，它使用多个参数解析结果承诺 - 当输入承诺本身确实产生多个值时(例如 $.ajax 确实如此)，每个参数都是各自的承诺决议.您只使用 response 获得了第一个，但是回调有 responseArray.length (letsSayTwo) 参数.

As stated in the docs for $.when, it resolves the result promise with multiple arguments - and when the input promises themselves did yield multiple values (such as $.ajax does), each argument is an arguments object of the respective promise resolution. You were only getting the first of them with response, but there are responseArray.length (letsSayTwo) arguments to the callback.

我应该如何从两个 AJAX 调用中获得正确的响应?

How should I go about getting the correct responses from both AJAX calls?

您想从每个arguments 对象，所以你可以使用 map:

$.when.apply(this, responseArray).done(function() {
  var responses = $.map(arguments, function(args) { return args[0]; }),
      spit = someAnalysis(responses);
  console.log(spit);
}).fail(function(jqXHR, textStatus, errorThrown) {
  console.log('fail: '+textStatus);
});

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