attrify

function attrify(config) {

    var properties = {};
    for (var prop in config) {
        if (prop && config.hasOwnProperty(prop)) {
            properties[prop] = (function(name) {
                return function() {
                    if (!arguments.length) {
                        return config[name];
                    }
                    config[name] = arguments[0];
                    return properties;
                };
            }(prop));
        }
    }
    return properties;
}


var x = attrify({
        width: 100,
        height: 200
    });

x.size = function() {
    console.log(this.width(), this.height());
};

x.size();

x.width(300).height(400);

console.log(x.width(), x.height());

x.size();