gistfile1.js

var app = new Y.App();

app.notify = function (req, res, next) {
    if (!this._route_evt) {
        this._route_evt = this.publish('route', {
            defaultFn: function () {
                next();
            }
        });
    }
    
    this.fire('route', {
        req: req,
        res: res
    });
};

app.route('/', 'notify', function (req, res, next) {
    var view = new Y.View();
    view.get('container').setText('HOME!');
    this.showView(view);
});

app.route('/about', 'notify', function (req, res, next) {
    var view = new Y.View();
    view.get('container').setText('About!');
    this.showView(view);
});

app.on('navigate', function (e) {
    Y.log('navigating!');
});

app.on('route', function (e) {
    Y.log('routing!');
    
    if (e.req.url === '/about') {
        // Don't let the user go to "/about", for some reason.
        e.preventDefault();
    }
});

app.render().navigate('/');
// => "navigating!"
// => "routing!"