Config Class

<?php 

class Config {

    protected static $instance;

    protected function __clone() {
    }

    public static function get() {
        if (self::$instance === null) {
            $class = __CLASS__;
            self::$instance = new $class;
        }
        return self::$instance;
    }

    public static function base($vars) {
        return self::get()->vars = $vars;
    }

    public static function set($key, $value) {
        if (strpos($key, '.') !== false) {
            $explode = explode('.', $key);

            $endcode = end($explode); // fetch last keyset
            unset($explode[count($explode) - 1]); // unset last keysey

            $array =& self::get()->vars;
            $current =& $array;

            foreach ($explode as $key) {
                if (isset($current[$key])) {
                    $current =& $current[$key];
                } else {
                    $current[$key] = array();
                    $current =& $current[$key];
                }
            }

            $current[$endcode] =& $value;
            return $current;
        } else {
            return self::get()->inject(array($key => $value));
        }
    }

    public static function key($key) {
        if (strpos($key, '.') !== false) {
            $explode = explode('.', $key);
            $current = isset(self::get()->vars[$explode[0]]) ? self::get()->vars[$explode[0]] : false;

            if (is_array($current)) {
                unset($explode[0]);
                foreach ($explode as $key) {
                    if (isset($current[$key])) {
                        $current = $current[$key];
                    } else {
                        $current = false;
                    }
                }
            }

            return $current;
        } else {
            return self::get()->{$key};
        }
    }

    public $vars = array();

    public function clean() {
        unset($this->vars);
        $this->vars = array();
    }

    public function inject(array $vars) {
        $this->vars = array_merge($this->vars, $vars);
        return $this;
    }

    public function dump() {
        ob_start();
        print_r($this->vars);
        return ob_get_clean();
    }

    public function get_array() {
        return $this->vars;
    }

    public function __set($k, $v) {
        $this->vars[$k] = $v;
    }

    public function __get($k) {
        if (isset($this->vars[$k])) {
            return $this->vars[$k];
        } else {
            return null;
        }
    }

    public function __isset($k) {
        return isset($this->vars[$k]);
    }

    public function __unset($k) {
        unset($this->vars[$k]);
    }
}

// set base array with config variables
Config::base($this->config);

// simple method of using:
Config::key('app.settings');

// or ...
$config = Config::get();

$config->app['settings'];

?>