如何将jQuery.ajax（）中的成功和错误处理程序中的值返回到父方法？

Ok, for sake of argument, let's say that the AJAX call MUST BE ASYNCHRONOUS.

好吧，为了论证，让我们说AJAX调用必须是异步的。

Basically, I have a jQuery AJAX call, and I want the success and error handlers to return a value to the parent method:

基本上，我有一个jQuery AJAX调用，我希望成功和错误处理程序返回一个值到父方法：

The code below does not work, since the AJAX call is asynchronous. Thus, the return value at the bottom of the function is returned before the repsonse is received:

由于AJAX调用是异步的，因此下面的代码不起作用。因此，在收到repsonse之前返回函数底部的返回值：

var isValid = false;

$.ajax({
    type: "POST",
    url: myurl,
    dataType: "JSON",
    data: $myData,
    async: true,
    success: function(data) {
        isValid = true;
    },
    error: function() {
        isValid = false;
    }
});

return isValid;

So, is there some way to pass a value BACK to the calling method for asynchronous AJAX calls?

那么，有没有办法将值BACK传递给异步AJAX调用的调用方法？

4 个解决方案

#1

The line

这条线

Return isValid;

Is going to execute before the call completes, because it's asynchronous.

将在调用完成之前执行，因为它是异步的。

Use

使用

async: false,

#2

Here's a solution I have come up with that answers my question.... (Thanks to @Rodaine for giving me the idea!)

这是我提出的一个解决我的问题的解决方案......（感谢@Rodaine给我的想法！）

In the calling method, I am specifying a callback function. Here is the plug-in that contains the AJAX call:

在调用方法中，我指定了一个回调函数。这是包含AJAX调用的插件：

function ajaxCall(options) {
    var url = options["url"] === undefined ? "" : options["url"];
    var addLink = options["addLink"] === undefined ? "" : options["addLink"];

    var $form = $(this).closest("form");
    var $formParamsString = $form.serialize();

    var aSuccess = [];
    var aError = [];

    if ($.isFunction(options["success"])) 
        aSuccess.push(options["success"]);

    if ($.isFunction(options["error"])) 
        aError.push(options["error"]);

    $.ajax({
        type: "POST",
        url: url,
        dataType: "JSON",
        data: $formParamsString,
        async: true, // Asynchronous to allow for loading image
        success: aSuccess,
        error: aError
    });
}

Now, when I call this function, I can specify a callback in the options Object:

现在，当我调用此函数时，我可以在选项Object中指定一个回调：

ajaxCall({
    url: "myWebService.cfm",
    success: function() {
        alert("We did it!");
    },
    error: function() {
        alert("Try again, fool!");
    }
});

#3

You can't do this because isValid would be always false.

你不能这样做，因为isValid总是假的。

If you need to do something following success/failure you should do:

如果您需要在成功/失败后做一些事情，您应该：

success: function(data) {
    isValid = true;
    otherFunction(isValid);
},
error: function() {
    isValid = false;
    otherFunction(isValid);
}

In this way you could handle the different cases

通过这种方式，您可以处理不同的情况

#4

-1

Use synchronouse ajax call

使用synchronouse ajax调用

set async to false.

将async设置为false。

#1