Best way to use Google's hosted jQuery, but fall back to my hosted library on Google fail

Question

What would be a good way to attempt to load the hosted jQuery at Google (or other Google hosted libs), but load my copy of jQuery if the Google attempt fails?

I\'m n

Answer 1

If you have modernizr.js embedded on your site, you can use the built-in yepnope.js to load your scripts asynchronously - among others jQuery (with fallback).

Modernizr.load([{
    load : '//ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js'
},{
    test : window.jQuery,
    nope : 'path/to/local/jquery-1.7.2.min.js',
    both : ['myscript.js', 'another-script.js'],
    complete : function () {
        MyApp.init();
    }
}]);

This loads jQuery from the Google-cdn. Afterwards it's checked, if jQuery was loaded successfully. If not ("nope"), the local version is loaded. Also your personal scripts are loaded - the "both" indicates, that the load-process is iniated independently from the result of the test.

When all load-processes are complete, a function is executed, in the case 'MyApp.init'.

I personally prefer this way of asynchronous script loading. And as I rely on the feature-tests provided by modernizr when building a site, I have it embedded on the site anyway. So there's actually no overhead.