A little necromancy update for the above JS for 2016 and nodebb 1.2.1:

<script>
$(window).on('action:ajaxify.end', function(event, data) {
    if (!app.user.uid && ajaxify.currentPage !== 'login' && ajaxify.currentPage !== 'register') {
        ajaxify.go('login');
    }
});
</script>