Optimize the Typekit load w/ Async & add a callback

optimize-typekit-async-load-with-callback

<!-- tk optimize // http://goo.gl/2A1IF7 -->
<script type = "text/javascript" > (function(e) {
	var t = 3e3;
	if (window.sessionStorage) {
		if (sessionStorage.getItem("useTypekit") === "false") {
			t = 0;
		}
	}
	var n = {
		kitId: "abcd1234",
		scriptTimeout: t
	},
	r = e.documentElement,
	i = setTimeout(function() {
		r.className = r.className.replace(/\bwf-loading\b/g, "") + " wf-inactive";
		if (window.sessionStorage) {
			sessionStorage.setItem("useTypekit", "false")
		}
	}, n.scriptTimeout),
	s = e.createElement("script"),
	o = false,
	u = e.getElementsByTagName("script")[0],
	a;
	r.className += "wf-loading";
	s.src = "//use.typekit.net/" + n.kitId + ".js";
	s.async = true;
	s.onload = s.onreadystatechange = function() {
		a = this.readyState;
		if (o || a && a != "complete" && a != "loaded") return;
		o = true;
		clearTimeout(i);
		try {
			Typekit.load(n)
		} catch (e) {}
	};
	u.parentNode.insertBefore(s, u)
})(document) </script>

/* 

In CSS

.wf-loading {
  body > .loader {
	  visibility: visible;
	  opacity:1;
	}
}
.wf-active, .wf-inactive {
	//
	body > .loader {
	  visibility: hidden;
	  opacity:0;
	}
}

*/