crem0r

<?php

class Base
{
    private $imported_functions = array();

    public function import($new_import)
    {
        $new_import->register($this);

        // the new functions to import
        $import_functions   = get_class_methods(get_class($new_import));

        foreach($import_functions as $key => $function_name)
        {
            $this->imported_functions[$function_name] = &$new_import;
        }
    }

    public function __call($method, $args)
    {
        // make sure the function exists
        if(array_key_exists($method, $this->imported_functions))
        {
            return call_user_func_array(array($this->imported_functions[$method], $method), $args);
        }
        throw new Exception ('Call to undefined method/class function: ' . $method);
    }
}

class User extends Base
{
    public $first_name;
    public $last_name;

    public function __construct()
    {
        $this->first_name = 'Ian';
        $this->last_name = 'Selby';
    }

    public function getFullName()
    {
        return $this->first_name . ' ' . $this->last_name;
    }
}

class UserFunctions
{
    protected $that = null;

    public function register($that)
    {
        $this->that = $that;
    }

    public function lastThenFirst()
    {
        return $this->that->last_name . ', ' . $this->that->first_name;
    }

    public function appendToLastname($name)
    {
        $this->that->last_name .= $name;
    }

    public function doExtentedFunction($statement)
    {
        return 'Im very dynamic ' . $statement . ' added by ' . $this->that->last_name;
    }
}

$user = new User();
$user->import(new UserFunctions());

echo $user->getFullName() . '<br />';
echo $user->appendToLastname('peterson');
echo $user->lastThenFirst() . '<br />';
echo $user->doExtentedFunction('bullshit');