gistfile1.js

YUI.add('root-cls', function (Y) {
    // Have to add the method name to be aggregated down the inheritance chain
    Y.Base._buildCfg.aggregates.push('getClassAttrs');
    
    Y.rootClass = Y.Base.create('root-class', Y.Base, [], {
        someInstanceMethod :  function () {}
    }, {
        ATTRS : {
            test : {
                validator : Y.Lang.isBoolean
            }
        },
        
        getClassAttrs : function () {
            var attrs = {},
                c = this.prototype.constructor;
            
            while (c) {
                Y.mix(attrs, c.ATTRS, true);
                c = (c.superclass ? c.superclass.constructor : null);
            }
            
            return attrs;
        }
    });
}, '1.0', {requires : ['base']});

YUI().use('root-cls', function (Y) {
    var mainClass = Y.Base.create('main-class', Y.Base, [Y.rootClass], {}, {
        ATTRS : {
            foo : {
                validator : Y.Lang.isNumber
            },
            bar : {
                validator : Y.Lang.isString
            }
        }
    });

    console.log(mainClass.getClassAttrs());
    
    var mySubClass = Y.Base.create('my-subclass', Y.Base, [mainClass], {}, {
        ATTRS : {
            baz : {
                validator : Y.Lang.isBoolean,
                value : false
            }
        }
    });

    console.log(mySubClass.getClassAttrs());
    console.log(new mySubClass());
});