有什么方法可以检查变量是否是真正的jqXHR？ [英] Any way to check whether a variable is a real jqXHR?

问题描述

正如标题已经提到的，有没有办法检查变量是否是真正的jqXHR？

As the title already mentions, is there a way to check whether a variable is a real jqXHR?

我的意思是（想象）：

var resource = $.get('/resource');

if (resource instanceof jqXHR)
{
    // do something
}

我想解决的实际问题是我正在研究的模态插件。

The actual problem I am trying to solve, is for a modal-plugin I'm working on.

$('#element').modal({
    content : function()
    {
        return $.get('/resource');
    }
});

而且，内容变量可以是 string 或 function 。如果是 string ，它将是静态的，如果 function 它将在每次打开模态时运行。

And, the content variable can be either string or function. In case of string, it will be static, in case of function it will be run every time upon opening the modal.

但是，我希望允许内容回调返回 jqXHR 或 string 。使用字符串非常简单， if（typeof返回==='string'），但是 jqXHR ？

But, I am looking to allow the content callback to return either jqXHR or string. With string it's pretty simple, if (typeof returned === 'string'), but what about jqXHR?

我知道我可以直接检查 string ，如果它不是字符串，假设它是 jqXHR ，但我希望我的插件尽可能强大，并禁止使用意外类型。

I know that I could simply check for string and in case it's not a string, assume it's jqXHR, but I want my plugin to be as strong as possible, and disallow working with unexpected types.

推荐答案

我建议只检查它是否是一个承诺对象。这将使您的代码更加健壮，因为如果用户需要执行更复杂的操作，用户可以返回自定义延迟对象，或者他们只需返回jqXHR以获得相同的效果。

I suggest just checking whether or not it is a promise object. This will make your code more robust in that the user can return a custom deferred object if they need to do something more complex, or they can simply return the jqXHR for the same effect.

if ($.type(resource) === "string") {
    doStuff(resource);
} elseif (resource && resource.promise) {
    resource.promise().done(doStuff);
} 

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