轉接器模式，顧名思義會在兩個同功能但不同的規格的東西中，當作中間溝通的橋樑，就有點像是健康的大頭菜因為放超過一個禮拜，直接變成壞掉的大頭菜，兩個東西都是大頭菜，但規格上可能不太一樣，這時候我們就需要一個大頭菜轉接器，直接把健康的大頭菜給轉到壞掉。
首先我們需要先建立健康的大頭菜、以及壞掉的大頭菜，別忘記要建立介面(Interface)來定義大頭菜的規格。
TurnipsInterface.php
/**
* Interface TurnipsInterface.
*/
interface TurnipsInterface
{
public function risePrice(int $price): int;
public function fallPrice(int $price): int;
public function getPrice(): int;
public function setPrice(int $price): int;
public function addCount(int $count): int;
public function subCount(int $count): int;
public function getCount(): int;
public function setCount(int $count): int;
public function calculatePrice(): int;
}Turnips.php
/**
* Class Turnips.
*/
class Turnips implements TurnipsInterface
{
/**
* @var int
*/
protected $price;
/**
* @var int
*/
protected $count;
/**
* Turnips constructor.
*
* @param int $price
* @param int $count
*/
public function __construct(int $price, int $count)
{
$this->price = $price;
$this->count = $count;
}
/**
* @param int $pirce
*
* @return int
*/
public function risePrice(int $price): int
{
$this->price += $price;
return $this->price;
}
/**
* @param int $price
*
* @return int
*/
public function fallPrice(int $price): int
{
$this->price -= $price;
return $this->price;
}
/**
* @return int
*/
public function getPrice(): int
{
return $this->price;
}
/**
* @param int $price
*
* @return int
*/
public function setPrice(int $price): int
{
$this->price = $price;
return $this->price;
}
/**
* @param int $count
*
* @return int
*/
public function addCount(int $count): int
{
$this->count += $count;
return $this->count;
}
/**
* @param int $count
*
* @return int
*/
public function subCount(int $count): int
{
$this->count -= $count;
return $this->count;
}
/**
* @return int
*/
public function getCount(): int
{
return $this->count;
}
/**
* @param int $count
*
* @return int
*/
public function setCount(int $count): int
{
$this->count = $count;
return $this->count;
}
/**
* @return int
*/
public function calculatePrice(): int
{
if (isset($this->price) && isset($this->count)) {
return $this->price * $this->count;
} else {
return 0;
}
}
}SpoiledInterface.php
/**
* Interface SpoiledInterface.
*/
interface SpoiledInterface
{
public function risePrice(int $price): int;
public function fallPrice(int $price): int;
public function addCount(int $count): int;
public function subCount(int $count): int;
public function calculatePrice(): int;
}Spoiled.php
/**
* Class Spoiled.
*/
class Spoiled implements SpoiledInterface
{
/**
* @var int
*/
protected $price;
/**
* @var int
*/
protected $count;
/**
* Spoiled constructor.
*
* @param int $price
* @param int $count
*/
public function __construct(int $price, int $count)
{
$this->price = $price;
$this->count = $count;
}
/**
* @param int $pirce
*
* @return int
*/
public function risePrice(int $price): int
{
$this->price += $price;
return $this->price;
}
/**
* @param int $price
*
* @return int
*/
public function fallPrice(int $price): int
{
$this->price -= $price;
return $this->price;
}
/**
* @param int $count
*
* @return int
*/
public function addCount(int $count): int
{
$this->count += $count;
return $this->count;
}
/**
* @param int $count
*
* @return int
*/
public function subCount(int $count): int
{
$this->count -= $count;
return $this->count;
}
/**
* @return int
*/
public function calculatePrice(): int
{
if (isset($this->price) && isset($this->count)) {
return 0 * $this->count;
} else {
return 0;
}
}
}再來我們需要為健康的大頭菜以及壞掉的大頭菜製作轉接器，概念上是引用壞掉的大頭菜介面，把健康的大頭菜丟進去，讓大頭菜以壞掉的方式來運作。
TurnipsAdapter.php
/**
* Class TurnipsAdapter.
*/
class TurnipsAdapter implements SpoiledInterface
{
/**
* @var TurnipsInterface
*/
protected $turnips;
/**
* @param TurnipsInterface $turnips
*/
public function __construct(TurnipsInterface $turnips)
{
$this->turnips = $turnips;
}
/**
* @param int $pirce
*
* @return int
*/
public function risePrice(int $price): int
{
$this->turnips->setPrice(0);
return $this->turnips->getPrice();
}
/**
* @param int $price
*
* @return int
*/
public function fallPrice(int $price): int
{
$this->turnips->setPrice(0);
return $this->turnips->getPrice();
}
/**
* @param int $count
*
* @return int
*/
public function addCount(int $count): int
{
$this->turnips->addCount($count);
return $this->count;
}
/**
* @param int $count
*
* @return int
*/
public function subCount(int $count): int
{
$this->turnips->subCount($count);
return $this->turnips->getCount();
}
/**
* @return int
*/
public function calculatePrice(): int
{
if (isset($this->price) && isset($this->count)) {
return 0 * $this->count;
} else {
return 0;
}
}
}寫完大頭菜轉接器以後，我們要來測試轉接器是否能夠正常使用，這裡會有幾個測試的重要項目：
- 測試大頭菜是否能夠正常賦予數量及價格，並且漲價 10 鈴錢、減少 20 組，最後算出價格是否符合。
- 測試大頭菜是否能夠正常賦予數量及價格，並且透過大頭菜轉接器把它轉成壞掉的大頭菜，最後漲價 10 鈴錢、減少 20 組，最後算出價格是否根本沒辦法賣鈴錢。
AdapterPatternTest.php
/**
* Class AdapterPatternTest.
*/
class AdapterPatternTest extends TestCase
{
/**
* 測試大頭菜是否能夠正常賦予數量及價格，並且漲價 10 鈴錢、減少 20 組，最後算出價格是否符合。
*
* @test
*/
public function test_can_rise_price_and_sub_count_on_turnips()
{
$turnips = new Turnips(100, 40);
$turnips->risePrice(10);
$turnips->subCount(20);
$this->assertEquals(2200, $turnips->calculatePrice());
}
/**
* 測試大頭菜是否能夠正常賦予數量及價格，並且透過大頭菜轉接器把它轉成壞掉的大頭菜
* 最後漲價 10 鈴錢、減少 20 組，最後算出價格是否根本沒辦法賣鈴錢。
*
* @test
*/
public function test_can_rise_price_and_sub_count_on_spoiled()
{
$turnips = new Turnips(100, 40);
$turnipsAdapter = new TurnipsAdapter($turnips);
$turnipsAdapter->risePrice(10);
$turnipsAdapter->subCount(20);
$this->assertEquals(0, $turnipsAdapter->calculatePrice());
}
}最後測試的執行結果會獲得如下：
PHPUnit Pretty Result Printer 0.28.0 by Codedungeon and contributors.
==> Configuration: ~/php-design-pattern/vendor/codedungeon/phpunit-result-printer/src/phpunit-printer.yml
PHPUnit 9.2.6 by Sebastian Bergmann and contributors.
==> AbstractFactoryTest ✔ ✔ ✔ ✔
==> BuilderPatternTest ✔ ✔
==> FactoryMethodTest ✔ ✔ ✔ ✔
==> PoolPatternTest ✔ ✔
==> PrototypePatternTest ✔ ✔
==> SimpleFactoryTest ✔ ✔ ✔ ✔
==> SingletonPatternTest ✔
==> StaticFactoryTest ✔ ✔ ✔ ✔ ✔
==> AdapterPatternTest ✔ ✔
Time: 00:00.050, Memory: 6.00 MB
OK (28 tests, 72 assertions)