如何让jQuery的等待，直到所有的get（）中的每一个请求（）得到完成 [英] How to make jQuery wait until all get() requests in each() get done

问题描述

我跟里面的一些网址的数组，我希望得到他们的HTML并将它推到另一个阵列（或JSON或别的东西）。

I have an array with some URLs inside, and I want to get their HTML and push it into another array (or JSON or something else).

在code看起来像这样;

The code looks like this;

url = ["/page_1.html", "/page_2.html"];
received_data = [];    

function() {
    url.each(function(i) {
        $.ajax({
            type: 'GET',
            url: this,
            success: function(data) {
                received_data.push(data);
            }
        });
    });

    // send received_data to some other server
};

现在的问题是，这个code不会等待AJAX​​（）请求，并开始发送received_data空。如何要等到所有的Ajax（）请求端（除非使用同步请求）？

The problem is that this code will not wait for the ajax() requests and start sending received_data empty. How to wait until all ajax() requests end (except using synchronous requests) ?

推荐答案

您可以使用 $的返回值。AJAX 为无极，并等待他们都使用满足 jQuery.when ：

You can use the return value of $.ajax as a Promise, and wait for all of them to be fulfilled using jQuery.when:

function() {
    var gets = [];
    url.each(function(i) {
        gets.push($.ajax({
            type: 'GET',
            url: this,
            success: function(data) {
                received_data.push(data);
            }
        }));
    });

    $.when.apply($, gets).then(function() {
        // send received_data to some other server
    });
};

到 $的电话。当看起来有点古怪，因为它希望接收该系列的S 无极等待为离散的参数，而不是一个数组，所以我们使用功能＃适用做到这一点。如果你打算这样做了很多，你可能会想扩展jQuery的一点：

The call to $.when looks a bit funky because it's expecting to receive the series of Promises to wait for as discrete arguments, rather than an array, so we use Function#apply to do that. If you're going to do this a lot, you might want to extend jQuery a bit:

(function($) {
    $.whenAll = function() {
        return $.when.apply($, arguments);
    };
})(jQuery);

那么你的使用就变成了：

Then your use becomes:

$.whenAll(gets).then(function() {
    // send received_data to some other server
});

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附注：我认为有什么东西在字功能上面您的真实code（例如， F =功能<前/ code>或 F：功能如果它在对象文本）。否则，它是一个无效的函数声明，因为它没有名字。 （如果你的执行的有东西，这是一个有效的匿名函数EX pression。）

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Side note: I assume there's something in front of the word function above in your real code (e.g., f = function, or f: function if it's in an object literal). Otherwise, it's an invalid function declaration as it has no name. (If you do have something, it's a valid anonymous function expression.)

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