等到所有多个异步ajax调用完成 [英] Wait till all multiple asynchronous ajax call are completed

问题描述

你好，我有多个ajax调用，我想做的是异步地激发它们，然后等到它们全部完成后再处理返回的数据.我尝试使用$ .when，但无济于事.这是我的代码:

Hello I have multiple ajax call, what I wanted to do is to fire all of them asynchronously then wait till all of them are finished before processing the returned data. I tried using $.when but to no avail. Here is my code:

//form_identifier_list is my flag to get the multiple forms in my html page
function test(form_identifier_list){
    var deffereds = [];

    $.each(form_identifier_list, function(key,value){
        var this_form = $(this).parents('.ajaxed_form');
        deffereds.push( $.post($(this_form).attr("action"), $(this_form).serializeForm()) );
    });

    $.when.apply($, deffereds).done(function(){
        //how to output response obj?? i tried console.log(data) to no avail
    }).fail(function(){

    }).always(function(){

    });
}

我还注意到我的Ajax请求没有响应(我已经在浏览器中验证了响应).

I also noticed my ajax requests do not have reponse (which i verified on my browser).

是否有一种方法可以使多个ajax调用异步触发，然后等到它们全部完成然后访问数据?

Is there a way to make multiple ajax calls fire asynchronously and then wait till all of them are finished then access the data?

谢谢

推荐答案

在 when ，其中有一段内容:

如果将多个Deferred对象传递给 jQuery.when()，该方法从新的母版"返回Promise 跟踪所有Deferred的聚合状态的Deferred对象 它已通过.

In the case where multiple Deferred objects are passed to jQuery.when(), the method returns the Promise from a new "master" Deferred object that tracks the aggregate state of all the Deferreds it has been passed.

ajax页面上也有此

从jQuery 1.5开始，由$ .ajax()返回的jqXHR对象实现了 承诺界面

The jqXHR objects returned by $.ajax() as of jQuery 1.5 implement the Promise interface

因此我们可以将ajax的返回值分配给一个变量，然后将这些变量传递给.when.

So we can just assign the return value of the ajax to a variable and pass those variables into the .when.

要稍微扩展.when页上给出的示例并集成任意数量的ajax调用，可以执行以下操作:

To expand slightly on the example given on the .when page and integrate any number of ajax calls, you can do something like this:

var ajaxes = [];
for(var i=0; i<10; i++) {
    ajaxes.push($.ajax('a.php', {data: {t: i}}));
}
$.when.apply($, ajaxes)
    .done(function(){
        for(var i=0;i<arguments.length; i++) {
            $('#output').append(arguments[i] + "<br>");
        };
    });

如果您知道已知数量的ajax调用，它将变得更简单...您可以执行以下操作:

If you have a known number of ajax calls, it gets a little simpler...you can do something more like this:

var a1 = $.ajax(...);
var a2 = $.ajax(...);
var a3 = $.ajax(...);
$.when(a1,a2,a3).done(function(o1, o2, o3) {
  $('#output').append(o1).append(o2).append(o3);
});

第一个示例基本上是在做同样的事情.

The first example is basically doing the same thing.

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