How to check if jquery package is being referenced

I have an MVC 3 Razor partial page that is dependent on jquery.validate.js and jquery.validate.unobtrusive.js.

Is it possible for the partial page to check 开发者_StackOverflowwhether or not there is, already, a reference to the .js packs?

Since this is a partial page, it's possible/probable that either the _Layout.cshtml or another included partial page has already referenced the .js packs. To avoid duplicate references to the .js packs, I would like the partial page(s) to be able to determine if it needs to add the reference to the packs or not.

The following bit of js code would check to see if the two plugins have been added to the jQuery object.

if (jQuery.validator != undefined && jQuery.validate != undefined) {
    //do something
}

You can check if jQuery and jQuery.validate are defined and load the script if it's not, but it's not really worth the effort - browsers are caching js files, so if you have two references, it will only download it once.

I'm not sure if this solves your problem, but there's a jquery function called getScript that loads a server script through a get request.

http://api.jquery.com/jQuery.getScript/

As it runs globally it might solve yout problem. You just have to do this:

$.getScript('url.js', function(){
//
});