gistfile1.php

<?php

require('DCI/MethodDelegator.php');
require('DCI/Role.php');

class Foo extends Role{
    public function test()
    {
        echo "I'm extended\n";
        echo "Even using data: {$this->value}\n";
    }
}

class TestData {
    use MethodDelegator;
    public $value;
}

$data = new TestData();
$data->value = "Data value";

$data->delegate('Foo');
$data->test();

?>

I'm extended
Even using data: Data value

MethodDelegator.php

<?php

Trait MethodDelegator
{
    private $roles = array();

    private $method_map = array();

    public function delegate($class)
    {
        $role = new $class($this);
        $this->roles[$class] = $role;

        foreach(get_class_methods($class) as $method)
        {
            $this->method_map[$method] = $role;
        }
    }

    public function remove_delegation($class)
    {
        $role = $this->roles[$class];
        unset($this->roles[$class]);

        $this->method_map = array_filter(
            $this->method_map,
            function($stored_role) use($role){
                return $stored_role !== $role;
            });
    }

    public function __call($method, $args)
    {
        if(! array_key_exists($method, $this->method_map)) {
            throw new Exception("Method $method doesn't exist on this object");
        }

        call_user_func_array(
            array($this->method_map[$method], $method), $args
        );
    }
}

Role.php

<?php

class Role
{
    private $data;

    public function __construct($data)
    {
        $this->data = $data;
    }

    public function __get($property)
    {
        return $this->data->$property;
    }

    public function __set($property, $value)
    {
        $this->data->$property = $value;
    }
}