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# Example: Add Behaviors to Objects with `mix`

Add behaviors to objects or static classes with `mix`

### Using `mix`

    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'.

### Adding functionality to individual objects

Static classes, such as `DOM`, are implemented as object literals with keys corresponding to public class methods. As such, static classes aren't candidates for instantiation or prototype extension. To add functionality to static classes, you need to work with the class's object literal.

In this example, `mix` is used to add a set of behaviors to a static class.

    var Logging = function () {
        var logger = null;

        return {
            initLogger : function (logNode) {
                if (!logger) {
                    logger = Y.one(logNode);
                }
            },

            log : function (message) {
                if (logger) {
                    logger.append('<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);

### Much like `augment`

`mix` works in similar fashion to `augment`. In fact, `augment` uses `mix` under the hood. However, rather than adding functionality to class definitions (i.e. function prototypes), `mix` can work with any object, including object literals and class instances.

See `augment` and `extend` for other techniques to help manage your code structure.