php—常见设计模式

工厂模式

/**
 * 工厂方法或者类生成对象，而不是在代码中直接new
 * 
 * 修改类名的时候，不需要每一个实例化语句都修改
 * 只需要修改对应的工厂方法
 * 
 * Class Factory
 * @package regina
 */
class Factory{

    static function createDatabase(){
        $db = Database::getInstance();
        return $db;
    }
}

单例模式

/**
 * 单例模式，节省资源,一个类只能实例化一个对象
 * 
 * 使某个类的对象仅允许创建一个
 * 
 * 为了实现单例模式，要私有化构造函数和clone魔术方法
 * Class Database
 * @package regina
 */
class Database{

    
    protected static $db;
    private function __construct(){

    }
    private function __clone(){

    }

    static function getInstance(){
        if (self::$db){
            return self::$db;
        }
        self::$db = new Database();
        return self::$db;
    }
}

注册模式

/**
 * 把new出来的对象保存在静态数值中，以便全局共享
 * 全局共享和交换对象
 * Class Register
 * @package regina
 */
class Register{
    protected static $array;
    static function set($name, $Obj){
        echo 'Register set run....';
        self::$array[$name] = $Obj;
    }
    static function get($name){
        echo 'Register get run....';
        return self::$array[$name];
    }

    function _unset($name){
        echo 'Register unset run....';
        unset(self::$array[$name]);
    }
}

适配器模式

/**
 * 将各种截然不同的函数接口封装成统一的API
 * Interface IDatabase
 * @package regina
 */
interface IDatabase{
    function connect($host, $username, $password, $dbname);
    function query();
    function close();
}
class Mysqli implements Database{
    protected $conn;
    function connect($host, $username, $password, $dbname){
        echo 'Mysqli connect run...';
    }
    function query(){
        echo 'Mysqli query run...';
    }
    function close(){
        echo 'Mysqli close run...';
    }
}
class Mysql implements Database{
    function connect($host, $username, $password, $dbname){
        echo 'Mysql connect run...';
    }
    function query(){
        echo 'Mysql query run...';
    }
    function close(){
        echo 'Mysql close run...';
    }
}

策略模式

/**

 * 将一组特定的行为和算法封装成类，以适应默写上下文的定义。

 * 减少模块耦合

 * Class MaleStrategy

 * @package regina\Strategy

 */

 interface UserStrategy{

​

    public function showAd();

    public function showcategory();

}

class MaleStrategy implements UserStrategy{

​

    function showAd(){

        echo 'MaleStrategy showAd run ...';

    }

​

    function showCategory(){

        echo 'MaleStrategy showCategory run ...';

    }

}

class FemaleStrategy implements UserStrategy{

​

    function showAd(){

        echo 'FemaleStrategy showAd run ...';

    }

​

    function showCategory(){

        echo 'FemaleStrategy showCategory run ...';

    }

}

//根据参数实例化对应的对象

class Page{

    protected $strategy;

    function index(){

        $this->strategy->showAd();

        $this->strategy->showCategory();

    }

​

    function setStrategy(\regina\Strategy\UserStrategy $strategy){

        $this->strategy = $strategy;

    }

}

//使用的时候才会实例化

//减少模块之间的耦合

$page = new Page;

$female = new \regina\Strategy\FemaleStrategy();

$page ->setStrategy($female);

$page ->index();

观察者模式

当一个对象发生改变时，依赖他的对象会全部收到通知

interface Observer{

    function update();

}

abstract class EventGenerator{

    private $observers = array();

    //添加观察者

    function addObserver(Observer $observer){

        $this->observers[] = $observer;

    }

    //通知

    function notify(){

        foreach($this->observers as $observer){

            $observer->update();

        }

    }

}

class Event extends \regina\EventGenerator{

    function trigger(){

        //事件发生

        echo 'Event'."<br>";

        //upodate

        $this->notify();

    }

}

class Observer implements \regina\Observer{

    public function update($event_info = null){

        echo 'update'. $event_info ."<br>";

    }

}

$event = new Event();

$event->addObserver(new Observer('对象1'));

$event->addObserver(new Observer('对象2'));

$event->trigger();

装饰器模式

/**

 * 装饰模式

 * 可以动态的给行为添加一些改变

 * 而不用改变主体逻辑

 * 减少主干代码与其他细节分支的耦合

 * Class regina

 */

 interface DrawDecorator{

    public function Befor();

    public function After();

}

class Test implements DrawDecorator{

    public $test;

    function __construct($test){

        $this->test = $test;

    }

    public function befor(){

        echo 'hello '.$this->test;

    }

    public function after(){

        echo 'goodbey '.$this->test;

    }

}

 class display {

    public function show(){

    echo '正体~~~';

    }

}

class regina extends \regina\Decorator\display {

    protected $Decorators = [];

    function AddDecorator(\regina\Decorator\DrawDecorator $decorator){

        $this->Decorators[]  = $decorator;

}

    function showDecorator(){

        foreach ($this->Decorators as $Decorator){

            $Decorator->befor();

        }

        parent::show();

        foreach ($this->Decorators as $Decorator ){

            $Decorator->after();

        }

    }

}

$rs = new regina();

$rs->AddDecorator(new \regina\Decorator\Test('regina'));

$rs->showDecorator();

挖坑待填~~~~~