decorator_classic_oop_pattern_part_2.2.js

var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
		var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
		if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
		else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
		return c > 3 && r && Object.defineProperty(target, key, r), r;
	};
/**
 * Base decorator for Coffee ingredients
 * @param target
 * @param cost
 * @returns {any}
 */
function baseCoffeeIngredientDecorator(target, cost) {
	// save a reference to the original constructor
	var original = target;
	// a utility function to generate instances of a class
	function construct(constructor, args) {
		var c = function () {
			return constructor.apply(this, args);
		};
		c.prototype = constructor.prototype;
		var ret = new c();
		ret.cost += cost;
		return ret;
	}

	// the new constructor behaviour
	var f = function () {
		var args = [];
		for (var _i = 0; _i < arguments.length; _i++) {
			args[_i - 0] = arguments[_i];
		}
		return construct(original, args);
	};
	// copy prototype so intanceof operator still works
	f.prototype = original.prototype;
	// return new constructor (will override original)
	return f;
}
/**
 * Decorator A
 */
function withMilk(target) {
	return baseCoffeeIngredientDecorator(target, 0.5);
}
/**
 * Decorator B
 */
function withWhip(target) {
	return baseCoffeeIngredientDecorator(target, 0.7);
}
/**
 * Decorator C
 */
function withSprinkles(target) {
	return baseCoffeeIngredientDecorator(target, 0.2);
}
/**
 * ConcreteComponent
 * (class for decorate)
 */
var Coffee = (function () {
	function Coffee() {
		this.cost = 1;
	}

	Coffee.prototype.getCost = function () {
		return this.cost;
	};
	Coffee = __decorate([
		withMilk,
		withWhip,
		withSprinkles
	], Coffee);
	return Coffee;
})();

var myCoffee = new Coffee();
console.log(myCoffee.getCost());