JS шаблон декоратор

decorator.js

//первый способ
function StripedBall( ball ) {
    this._ball = ball    
}
StripedBall.prototype =  {
    constructor: StripedBall,
 
    draw: function() {
        this._ball.draw();
        //и еще какие то действия
    },
    inc: function() {
        return this._ball.inc();
        //и еще какие то действия
    }
}
 
var ball = new SpeckledBall( new StripedBall( new Ball({ radius:100, color:"red"})));

//второй способ
function MakeStripedBall( ball ) {
    var function_name = "draw";
    var prev_func = ball[ function_name ];
 
    ball[ function_name ] = function() {
        prev_func.apply( this, arguments )
        console.log("and with stripes");
    };
 
    return ball;
}
var ball = MakeStripedBall( MakeSpeckledBall( new Ball({ radius: 150, color: "blue" })));
 
 
 
//способ третий
var tree = {};
tree.decorate = function () {
	console.log('Make sure the tree won\'t fall');
};
 
tree.getDecorator = function (deco) {
	tree[deco].prototype = this;
	return new tree[deco];
};
 
tree.RedBalls = function () {
	this.decorate = function () {
		this.RedBalls.prototype.decorate();
		console.log('Put on some red balls');
	}
};
 
tree.BlueBalls = function () {
	this.decorate = function () {
		this.BlueBalls.prototype.decorate();
		console.log('Add blue balls');
	}
};
 
tree.Angel = function () {
	this.decorate = function () {
		this.Angel.prototype.decorate();
		console.log('An angel on the top');
	}
};
 
tree = tree.getDecorator('BlueBalls');
tree = tree.getDecorator('Angel');
tree = tree.getDecorator('RedBalls');
 
tree.decorate();


//способ номер четыре
function Sale(price) {
    this.price = price || 0;
}
Sale.prototype.getPrice = function() {
    return this.price;
}
Sale.decorators = {};

Sale.decorators.fedtax = {
    getPrice: function() {
        var price = this.uber.getPrice();
        price += price * 5 / 100;
        return price
    }
}

Sale.prototype.decorate = function(decorator) {
    var
        F = function() {}
        , overrides = this.constructor.decorators[decorator]
        , i
        , newObj
    ;
    
    F.prototype = this;
    newObj = new F();
    newObj.uber = F.prototype;
    
    for(i in overrides) {
        if(overrides.hasOwnProperty(i)) {
            newObj[i] = overrides[i];
        }
    }
    
    return newObj;
}

var sale = new Sale(100);
sale.decorate('fedtax');
sale.getPrice();


//пятый метод
function Sale(price) {
    this.price = price || 0;
    this.decorators_list = [];
}
Sale.prototype.getPrice = function() {
    var
        price = this.price
        , i
        , max = this.decorator_list.length
        , name
    ;
    
    for(i = 0; i < max; i += 1) {
        name = this.decorator_list[i];
        price = Sale.decorators[name].getPrice(price);
    }
    
    return price;
}
Sale.decorators = {};
Sale.decorators.fedtax = {
    getPrice: function() {
        var price = this.uber.getPrice();
        price += price * 5 / 100;
        return price
    }
}

Sale.prototype.decorate = function(decorator) {
    this.decorator_list.push(decorator);
}

Четвертый способ не рабочий
var sale = new Sale(100);
sale.decorate('fedtax');// цена 100 долларов
sale.decorate('quebec');// добавить федеральный налог
sale.decorate('money');// форматировать как денежную сумму
console.log(sale.getPrice());// “$112.88”
112,88 не получится