A few design patterns

dummy

dummy

Factory.php

<?php

class Foo{
    public $foo = TRUE;
}

class Factory{
    public static function create($Product){
        return new $Product;
    }
}

var_dump(Factory::create('Foo'));

Singleton.php

<?php

class Singleton{
    private static $instance;

    private $var = 0;

    private function __construct(){
    }

    public function __clone(){
        trigger_error('Cloning of singletons is not allowed!', E_USER_ERROR);
    }

    public function __wakeup(){
        static::$instance = self::$instance;
    }

    public static function getInstance(){
        if(!isset(self::$instance)){
            self::$instance = new Singleton();
        }

        return self::$instance;
    }

    public function process(){
        return $this->var++;
    }
}
/*
class Singleton implements Serializable{
    private static $instance;

    private $var = 0;

    private function __construct(){
    }

    public function __clone(){
        trigger_error('Cloning of singletons is not allowed!', E_USER_ERROR);
    }

    public function serialize(){
        return serialize($this->var);
    }

    public function unserialize($serialized){
        $this->var = unserialize($serialized);
    }

    public static function getInstance(){
        if(!isset(self::$instance)){
            self::$instance = new Singleton();
        }

        return self::$instance;
    }

    public function process(){
        return $this->var++;
    }
}
 */

$bar = Singleton::getInstance();
$bar->process();

$baz = Singleton::getInstance();
$baz->process();

var_dump(serialize($baz));
$baz = unserialize(serialize($baz));
$baz->process();

var_dump($bar, $baz);

Strategy.php

<?php

interface Strategy{
    public function compute();
}

class FooAlgorithm implements Strategy{
    public function compute(){
        return 42;
    }
}

class BarAlgorithm implements Strategy{
    public function compute(){
        return 42+42;
    }
}

class Consumer{
    public $algo;

    public function __construct(Strategy $strategy){
        $this->algo = $strategy;
    }

    public function doJob(){
        return $this->algo->compute();
    }
}

if(!TRUE){
    $a = new Consumer(new BarAlgorithm);
}
else{
    $a = new Consumer(new FooAlgorithm);
}

var_dump($a->doJob());