gistfile1.js

YUI.add('user-view', function (Y) {

    Y.UserView = Y.Base.create('userView', Y.View, [], {
        template: Y.Handlebars.templates['user'],

        initializer: function () {
            var user = this.get('user');

            if (user) {
                user.addTarget(this);
            }

            this.after({
                'userChange' : this._afterUserChange,
                'user:change': this.render
            });
        },

        render: function () {
            var content = this.template(this.get('user').getAttrs());

            this.get('container').setHTML(content);
            return this;
        },

        _afterUserChange: function (e) {
            if (e.prevVal) {
                e.prevVal.removeTarget(this);
            }

            if (e.newVal) {
                e.newVal.addTarget(this);
                this.render();
            }
        }
    });

}, '0.0.1', {
    requires: ['handlebars-base', 'view', 'templates']
});