学习JavaScript设计模式之模板方法模式

/* 抽象父类：饮料 */var Beverage = function(){};// (1) 把水煮沸Beverage.prototype.boilWater = function() {  console.log("把水煮沸");};// (2) 沸水浸泡Beverage.prototype.brew = function() {  throw new Error("子类必须重写brew方法");};// (3) 倒进杯子Beverage.prototype.pourInCup = function() {  throw new Error("子类必须重写pourInCup方法");};// (4) 加调料Beverage.prototype.addCondiments = function() {  throw new Error("子类必须重写addCondiments方法");};/* 模板方法 */Beverage.prototype.init = function() {  this.boilWater();  this.brew();  this.pourInCup();  this.addCondiments();}/* 实现子类 Coffee*/var Coffee = function(){};Coffee.prototype = new Beverage();// 重写非公有方法Coffee.prototype.brew = function() {  console.log("用沸水冲泡咖啡");};Coffee.prototype.pourInCup = function() {  console.log("把咖啡倒进杯子");};Coffee.prototype.addCondiments = function() {  console.log("加牛奶");};var coffee = new Coffee();coffee.init();

/* 添加钩子方法 */Beverage.prototype.customerWantsCondiments = function() {  return true;};Beverage.prototype.init = function() {  this.boilWater();  this.brew();  this.pourInCup();  if(this.customerWantsCondiments()) {    this.addCondiments();  }}/* 实现子类 Tea*/var Tea = function(){};Tea.prototype = new Beverage();// 重写非公有方法Tea.prototype.brew = function() {  console.log("用沸水冲泡茶");};Tea.prototype.pourInCup = function() {  console.log("把茶倒进杯子");};Tea.prototype.addCondiments = function() {  console.log("加牛奶");};Tea.prototype.customerWantsCondiments = function() {  return window.confirm("需要添加调料吗？");};var tea = new Tea();tea.init();