YUI Library Examples: The YUI Global Object: Add Behaviors to Objects with mix

<!-- include yui -->
<script type="text/javascript" src="../../build/yui/yui.js"></script>
 
YUI().use("node", function(Y) {
    // This method is in the core of the library, so we don't have to use() any
    // additional modules to access it.  However, this example requires 'node'.

var Logging = function () {
    var logger = null;
 
    return {
        initLogger : function (logNode) {
            if (!logger) {
                logger = Y.one(logNode);
            }
        },
 
        log : function (message) {
            if (logger) {
                logger.set('innerHTML', logger.get('innerHTML') + '<p>' + message + '</p>');
            }
        }
    }
}();
 
var PageController = function () {
    var app_const = 12345;
 
    return {
 
        getConst : function () { 
            return app_const;
        },
 
        logConst : function () {
            this.initLogger('#demo_logger');
            this.log('PageController class constant = ' + this.getConst() +
                      ', logged courtesy of object augmentation via Y.mix.');
        }
    };
}();
 
Y.mix(PageController, Logging);
 
Y.on('click', PageController.logConst, '#demo_btn', PageController);