Declarative and modular approach to http://css-tricks.com/multiple-simultaneous-ajax-requests-one-callback-jquery/

gistfile1.txt

<a href="#" data-load-css="wtf.css" data-load-fn="wtfFn">Some module link</a>
<form action="">
    <button data-load-css="wtf2.css" data-load-fn="wtf2Fn">Yeah buddy</button>
</form>

var moduleFuncs = {
    wtfFn: function() {},
    wtf2Fn: function() {}
};

$('[data-load-css]').on('click.load-modules', loadModule);

function loadModule(event) {
    event.preventDefault();
    var url = $(this).data('load-css');
    var callback = $(this).data('load-fn');

    var urlpromise = $.ajax(url);
    $.when(urlpromise).then(moduleFuncs[callback]);
}