callback.html

<html>
<head>
<script>

function init() {
	console.log('hash', location.hash);

	var hash = {};
	location.hash.replace(/^#\/?/, '').split('&').forEach(function(kv) {
		var spl = kv.indexOf('=');
		if (spl != -1) {
			hash[kv.substring(0, spl)] = decodeURIComponent(kv.substring(spl+1));
		}
	});

	console.log('initial hash', hash);

	if (hash.access_token) {
		window.opener.postMessage(JSON.stringify({
			type:'access_token',
			access_token: hash.access_token,
			expires_in: hash.expires_in || 0
		}), '*');

		window.close();
	}
}

</script>
</head>
<body onload="init()">

</body>
</html>