工厂模式：工厂方法——用PHP改写head first中的例子

工厂方法(Factory Method)模式是指：定义一个创建对象的接口，但由子类决定要实例化的类是哪一个。工厂方法让类把实例化推迟到了子类。在这个例子中，生产何种pizza是在继承了抽象类的子类中进行的。

Pizza类

<?php

	abstract class Pizza {
		public $name;
		public $dough;
		public $sauce;
		
		function prepare() {
			echo 'Preparing '.$this->name.'<br />';
			echo 'Tossing dough...<br />';
			echo 'Adding sause...<br />';
		}
		
		function bake() {
			echo 'Bake for 25 minutes at 350';
		}
		
		function cut() {
			echo 'Cutting the pizza into diagonal slices';
		}
		
		function box() {
			echo 'Place pizza in official PizzaStore box';
		}
		
		function getName() {
			echo  $this->name;
		}
	}

?>

 

PizzaStore类

<?php
 abstract class PizzaStore {
  abstract function createPizza($type);
  
  public function orderPizza($type) {
   $pizza = $this->createPizza($type);
   $pizza->prepare();
   $pizza->bake();
   $pizza->cut();
   $pizza->box();
   return $pizza;
  }
 }

?>

 

 

NYPizzaStore类

<?php

	class NYPizzaStore extends PizzaStore {
		function createPizza($type) {
			if($type == 'cheese') {
				return new NYStyleCheesePizza();
			} elseif ($type == 'pepperioni') {
				return new NYStylePepperioniPizza();
			} elseif ($type == 'clam') {
				return new NYSytleClamPizza();
			} elseif ($type == 'veggie') {
				return new NYSytleVeggiePizza();
			}
		}
	}

?>

  

NYStyleCheesePizza 类

<?php

class NYStyleCheesePizza extends Pizza {
	public function __construct() {
		$this->name = '"NY Style Sauce and Cheese Pizza';
		$this->dough = "Thin Crust Dough";
		$this->sauce = "Marinara Sauce";
	}
}

?>

 

客户

<?php
	include_once 'Pizza.php';
	include_once 'PizzaStore.php';
	include_once 'NYPizzaStore.php';
	include_once 'NYStyleCheesePizza.php';
	
	$pizzaStore = new NYPizzaStore();
	$pizza = $pizzaStore->orderPizza('cheese');
	$pizza->getName();
?>