POO - PARAMETERHOLDER CLASS

<?php
/**
 * Class ParameterHolder provides a base class for managing parameters.
 *
 * @author     Quentin Berlemont <quentinberlemont@gmail.com>
 * @copyright  Copyright (C) 2010 Quentin Berlemont
 * @license    http://www.gnu.org/licenses/lgpl.html LGPLv3
 */
class ParameterHolder extends ArrayObject
{
    /**
     * Constructs an instance of ParameterHolder.
     *
     * @param  array $parameters Optional, an array of parameters as key/value
     *                           pair.
     * @return void
     */
    public function __construct(array $parameters = array())
    {
        parent::__construct($parameters, parent::ARRAY_AS_PROPS);
    }

    /**
     * Sets the value at the specified index.
     *
     * @param  string $index The index being set.
     * @param  mixed  $value The value for the index.
     * @return void
     */
    public function offsetSet($index, $value)
    {
        if (is_array($value)) {
            $value = new static($value);
        }

        parent::offsetSet($index, $value);
    }

    /**
     * Returns the value at the specified index.
     *
     * @param  string $index The index with the value.
     * @return mixed  Returns the value at the specified index or FALSE.
     */
    public function offsetGet($index)
    {
        $value = parent::offsetGet($index);

        if (is_array($value)) {
            $this->offsetSet($index, $value);

            return parent::offsetGet($index);
        }

        return $value;
    }

}

// Example:

$initParams = array('third_section' => array('php_version' => PHP_VERSION));

$parameterHolder = new ParameterHolder($initParams);

$parameterHolder['first_section']        = array();
$parameterHolder['first_section']['one'] = 1;
$parameterHolder['first_section']['two'] = 2;

$parameterHolder->second_section       = array();
$parameterHolder->second_section->path = '/path/to/something';
$parameterHolder->second_section->url  = 'http://php.net/';

// prints: 1
echo $parameterHolder->first_section->one;

// prints: /path/to/something
echo $parameterHolder['second_section']['path'];

// prints: 5.3.0
echo $parameterHolder->third_section->php_version;

// prints: 5.3.0
echo $parameterHolder['third_section']['php_version'];

// prints: bool(true)
var_dump(isset($parameterHolder->second_section->path));

unset($parameterHolder->second_section->path);

// prints: bool(false)
var_dump(isset($parameterHolder->second_section->path));

// prints:
//ParameterHolder Object
//(
//    [storage:ArrayObject:private] => Array
//        (
//            [third_section] => ParameterHolder Object
//                (
//                    [storage:ArrayObject:private] => Array
//                        (
//                            [php_version] => 5.3.0
//                        )
//                )
//            [first_section] => ParameterHolder Object
//                (
//                    [storage:ArrayObject:private] => Array
//                        (
//                            [one] => 1
//                            [two] => 2
//                        )
//                )
//            [second_section] => ParameterHolder Object
//                (
//                    [storage:ArrayObject:private] => Array
//                        (
//                            [url] => http://php.net/
//                        )
//                )
//        )
//)
print_r($parameterHolder);
?>