多个ajax调用的jQuery回调

Question

我想在click事件中进行三个Ajax调用。每个ajax调用都会执行不同的操作，并返回最终回调所需的数据。调用本身并不相互依赖，它们可以同时进行，但是当三个都完成时，我希望有一个最终的回调。

$('#button').click(function() {
    fun1();
    fun2();
    fun3();
//now do something else when the requests have done their 'success' callbacks.
});

var fun1= (function() {
    $.ajax({/*code*/});
});
var fun2 = (function() {
    $.ajax({/*code*/});
});
var fun3 = (function() {
    $.ajax({/*code*/});
});

Answer 1

这是我写的一个回调对象，您可以设置单个回调以在全部完成后触发，也可以让每个回调都有自己的回调并在全部完成后触发它们：

注意

从jQuery 1.5+开始，您可以按照另一个答案中所述使用deferred方法：

  $.when($.ajax(), [...]).then(function(results){},[...]);

此处延迟的示例

对于jQuery
<1.5，下面的方法将起作用，或者如果您需要在未知时间触发ajax调用，如此处所示，有两个按钮：单击两个按钮后触发

[用法]

对于 单一 的回调完成后： 工作实例

// initialize here
var requestCallback = new MyRequestsCompleted({
    numRequest: 3,
    singleCallback: function(){
        alert( "I'm the callback");
    }
});

//usage in request
$.ajax({
    url: '/echo/html/',
    success: function(data) {
        requestCallback.requestComplete(true);
    }
});
$.ajax({
    url: '/echo/html/',
    success: function(data) {
        requestCallback.requestComplete(true);
    }
});
$.ajax({
    url: '/echo/html/',
    success: function(data) {
        requestCallback.requestComplete(true);
    }
});

每个都完成时都有 自己的 回调： 工作示例

//initialize 
var requestCallback = new MyRequestsCompleted({
    numRequest: 3
});

//usage in request
$.ajax({
    url: '/echo/html/',
    success: function(data) {
        requestCallback.addCallbackToQueue(true, function() {
            alert('Im the first callback');
        });
    }
});
$.ajax({
    url: '/echo/html/',
    success: function(data) {
        requestCallback.addCallbackToQueue(true, function() {
            alert('Im the second callback');
        });
    }
});
$.ajax({
    url: '/echo/html/',
    success: function(data) {
        requestCallback.addCallbackToQueue(true, function() {
            alert('Im the third callback');
        });
    }
});

[代码]

var MyRequestsCompleted = (function() {
    var numRequestToComplete, requestsCompleted, callBacks, singleCallBack;

    return function(options) {
        if (!options) options = {};

        numRequestToComplete = options.numRequest || 0;
        requestsCompleted = options.requestsCompleted || 0;
        callBacks = [];
        var fireCallbacks = function() {
            alert("we're all complete");
            for (var i = 0; i < callBacks.length; i++) callBacks[i]();
        };
        if (options.singleCallback) callBacks.push(options.singleCallback);

        this.addCallbackToQueue = function(isComplete, callback) {
            if (isComplete) requestsCompleted++;
            if (callback) callBacks.push(callback);
            if (requestsCompleted == numRequestToComplete) fireCallbacks();
        };
        this.requestComplete = function(isComplete) {
            if (isComplete) requestsCompleted++;
            if (requestsCompleted == numRequestToComplete) fireCallbacks();
        };
        this.setCallback = function(callback) {
            callBacks.push(callBack);
        };
    };
})();