本文透過一個簡單的投訴頁面，示範多種 PHP 設計模式的實作，包含單例、工廠、觀察者、橋接、適配器、裝飾器、責任鏈、策略等模式。
<?php
/* 設計模式練習
* 1. 資料庫連線類（單例模式）
* 2. 呼叫介面實作留言板功能（工廠模式）
* 3. 實作分級舉報處理功能（責任鏈模式）
* 4. 發送不同組合的舉報資訊（橋接模式）
* 5. 發送不同格式的舉報資訊（適配器模式）
* 6. 在投訴內容後自動追加時間（裝飾器模式）
* 7. 根據會員登入資訊變換顯示風格（觀察者模式）
* 8. 根據發文長度加經驗值（策略模式）
*/
interface DB { function conn(); }
/** 單例模式 */
class MysqlSingle implements DB {
protected static $_instance = NULL;
public static function getInstance() {
if (!self::$_instance instanceof self) {
self::$_instance = new self;
}
return self::$_instance;
}
final protected function __construct() { echo 'Mysql單例建立成功<br>'; }
final protected function __clone() { return false; }
public function conn() { echo 'Mysql連線成功<br>'; }
}
/** 工廠模式 */
interface Factory { function createDB(); }
class MysqlFactory implements Factory {
public function createDB() {
echo 'Mysql工廠建立成功<br>';
return MysqlSingle::getInstance();
}
}
/** 觀察者模式：根據使用者名稱顯示不同風格 */
class Observer implements SplSubject {
protected $_observers = NULL;
public $_style = NULL;
public function __construct($style) {
$this->_style = $style;
$this->_observers = new SplObjectStorage();
}
public function show() { $this->notify(); }
public function attach(SplObserver $observer) { $this->_observers->attach($observer); }
public function detach(SplObserver $observer) { $this->_observers->detach($observer); }
public function notify() {
$this->_observers->rewind();
while ($this->_observers->valid()) {
$observer = $this->_observers->current();
$observer->update($this);
$this->_observers->next();
}
}
}
class StyleA implements SplObserver {
public function update(SplSubject $subject) { echo $subject->_style . ' 模組A<br>'; }
}
class StyleB implements SplObserver {
public function update(SplSubject $subject) { echo $subject->_style . ' 模組B<br>'; }
}
/** 橋接模式：根據不同方式進行投訴 */
class Bridge {
protected $_obj = NULL;
public function __construct($obj) { $this->_obj = $obj; }
public function msg($type) {}
public function show() { $this->msg(); $this->_obj->msg(); }
}
class BridgeEmail extends Bridge { public function msg() { echo 'Email>>'; } }
class BridgeSms extends Bridge { public function msg() { echo 'Sms>>'; } }
class Normal { public function msg() { echo 'Normal<br>'; } }
class Danger { public function msg() { echo 'Danger<br>'; } }
/** 適配器模式：發送不同格式的舉報資訊 */
class Serialize {
public $content = NULL;
public function __construct($content) { $this->content = serialize($content); }
public function show() { return '序列化格式：<br>' . $this->content; }
}
class JsonAdapter extends Serialize {
public function __construct($content) {
parent::__construct($content);
$tmp = unserialize($this->content);
$this->content = json_encode($tmp, TRUE);
}
public function show() { return 'Json格式：<br>' . $this->content; }
}
/** 裝飾器模式：在投訴內容後自動追加時間 */
class Base {
protected $_content = NULL;
public function __construct($content) { $this->_content = $content; }
public function getContent() { return $this->_content; }
}
class Decorator {
private $_base = NULL;
public function __construct(Base $base) { $this->_base = $base; }
public function show() { return $this->_base->getContent() . '>>系統時間：' . date('Y-m-d H:i:s', time()); }
}
/** 責任鏈模式：分級舉報處理功能 */
class Level1 {
protected $_level = 1; protected $_top = 'Level2';
public function deal($level) {
if ($level <= $this->_level) { echo '處理級別：1<br>'; return; }
$top = new $this->_top; $top->deal($level);
}
}
class Level2 {
protected $_level = 2; protected $_top = 'Level3';
public function deal($level) {
if ($level <= $this->_level) { echo '處理級別：2<br>'; return; }
$top = new $this->_top; $top->deal($level);
}
}
class Level3 {
protected $_level = 3; protected $_top = 'Level2';
public function deal($level) { echo '處理級別：3<br>'; return; }
}
// 表單處理邏輯
if (!empty($_POST)) {
echo '<h1>PHP設計模式</h1>';
// 工廠+單例模式連線資料庫
$mysqlFactory = new MysqlFactory();
$single = $mysqlFactory->createDB();
$single->conn(); echo '<br>';
// 觀察者模式
$username = $_POST['username'];
$ob = new Observer($username);
$a = new StyleA(); $ob->attach($a);
$b = new StyleB(); $ob->attach($b);
$ob->show(); echo '<br>';
$ob->detach($b); $ob->show(); echo '<br>';
// 橋接模式
$typeM = $_POST['typeM'];
$typeN = 'Bridge' . $_POST['typeN'];
$obj = new $typeN(new $typeM); $obj->show(); echo '<br>';
// 適配器模式
$post = $_POST;
$obj = new Serialize($post); echo $obj->show(); echo '<br>';
$json = new JsonAdapter($post); echo $json->show(); echo '<br><br>';
// 裝飾器模式
$content = $_POST['content'];
$decorator = new Decorator(new Base($content)); echo $decorator->show(); echo '<br>';
// 責任鏈模式
echo '<br>';
$level = $_POST['level'];
$deal = new Level1(); $deal->deal(intval($level));
return;
}
require("0.html");
<!DOCTYPE html>
<html>
<head>
<title>PHP設計模式</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style> div{border:solid gray 1px;margin-top:10px;height: 100px;width: 200px;} </style>
</head>
<body>
<form action="0.php" method="post">
<h1>用戶名</h1>
<select id="username" name="username">
<option value="Tom">Tom</option>
<option value="Lily">Lily</option>
</select>
<h1>投訴方式</h1>
<select id="type" name="typeM">
<option value="Normal">Normal</option>
<option value="Danger">Danger</option>
</select>
<select id="type" name="typeN">
<option value="Email">Email</option>
<option value="Sms">Sms</option>
</select>
<h1>處理級別</h1>
<select id="level" name="level">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
</select>
<h1>投訴內容</h1>
<textarea id="content" name="content" rows="3"></textarea>
<button type="submit">提交</button>
</form>
</body>
</html>
此範例完整展示了八種設計模式在實際專案中的應用，適合學習 PHP 設計模式的開發者參考。
