gistfile1.php

class Pig {
  function oink() {
    print "Oink";
  }
}

abstract class Decorator {
  protected $obj;
  function __construct($object) {
    $this->obj = $object;
  }
  function __call($name, $args) {
    return call_user_func_array(array($this->obj, $name), $args);
  }
}

class FlyingPig extends Decorator {
  function fly() {
    print "I'm flying!";
  }
}

$pig = new Pig;
$flying_pig = new FlyingPig($pig);
$flying_pig->fly();
$flying_pig->oink();