decoratorJS.js

function Sandwich(name) {
   this.name = name;
}

Sandwich.prototype.eat = function () {
   console.log("I'm eating " + this.name);
}

function Subway () {
   Sandwich.call(this, 'subway');
}

Subway.prototype = Object.create(Sandwich.prototype);
Subway.prototype.cost = function () {
   return 5;
}

////

Subway.sixInch = function (subwayObj) { //Method on Subway function object
  var cost = subwayObj.cost(); //Get current cost of sandwich
    subwayObj.cost = function () { //We aren't changing interface but providing more functionality
    	return cost - 1;
    }
}    
 
Subway.footLong = function (subwayObj) {}; //Default is Foot Long 
Subway.partySub = function (subwayObj) { 
  var cost = subwayObj.cost(); 
    subwayObj.cost = function () { 
    	return cost + 3;
    }
}

Subway.partySub = function (subwayObj) { 
  var cost = subwayObj.cost(); 
    subwayObj.cost = function () { 
    	return cost + 3;
    }
}

Subway.pickle = function (subwayObj) { 
  var cost = subwayObj.cost(); 
    subwayObj.cost = function () { 
    	return cost + 0.12;
    }
}

Subway.mustard = function (subwayObj) { 
  var cost = subwayObj.cost(); 
    subwayObj.cost = function () { 
    	return cost + 0.25;
    }
}

Subway.ketchup = function (subwayObj) { 
  var cost = subwayObj.cost(); 
    subwayObj.cost = function () { 
    	return cost + 0.10;
    }
}


var mySandwich = new Subway(); // current cost of sandwich 5
Subway.partySub(mySandwich); // add 3 and cost would be 8
Subway.pickle(mySandwich); // add 0.12 and cost would be 8.12
Subway.mustard(mySandwich); // add 0.25 and cost would be 8.37
console.log(mySandwich.cost());//8.37


function Sandwich() {
  this._cost = 0;
}

Sandwich.prototype.cost = function () {
  return this._cost;
}

function SandwichDecorator(sandwich) {
  Sandwich.call(this);
    this.sandwich = sandwich;
}
SandwichDecorator.prototype = Object.create(Sandwich.prototype);
SandwichDecorator.prototype.cost = function () {
  return this._cost + this.sandwich.cost();
}

function Pickle(sandwich) {
  SandwichDecorator.call(this, sandwich);
    this._cost = 0.12;
}
Pickle.prototype = Object.create(SandwichDecorator.prototype);

function Subway() {
  Sandwich.call(this);
    this._cost = 5;
}
Subway.prototype = Object.create(Sandwich.prototype);


var mySandwich = new Subway();
mySandwich = new Pickle(mySandwich);
console.log(mySandwich.cost()); //5.12