factory pattern.php

<!-- product.php -->
<?php
class Product {
  function __construct() {
  }
}
?>

<!-- client.php -->
<?php 
class Client {
  public function __construct() {
    $this->product = new Product();  <-- this is bad, because we can't mock it out in test
  }
}
?>

<!-- factory.php -->
<?php
class Factory {
  public function produce() {
    return new Product();
  }
}
?>

<!-- client2.php -->
<?php
class Client2 {
  public function __construct($factory=new Factory()) {
    $this->product = $factory->produce();
  }
}
?>

<!-- test_client2.php -->
<?php
new Client2($someMockFactory);
?>