PHP decorator base class

BaseDecorator.php

<?php

class BaseDecorator {
    private $component;
    private $methods = array();
    private $properties = array();

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

    public function __call($name, $args) {
        if (!isset($this->methods[$name])) {
            $this->methods[$name] = method_exists($this->component, $name);
        }

        if ($this->methods[$name]) {
            return call_user_func_array(array($this->component, $name), $args);
        }
    }

    public function __get($name) {
        if (!isset($this->properties[$name])) {
            $this->properties[$name] = property_exists($this->component, $name);
        }

        if ($this->properties[$name]) {
            return $this->component->$name;
        }
    }

    public function __set($name, $value) {
        if (!isset($this->properties[$name])) {
            $this->properties[$name] = property_exists($this->component, $name);
        }

        if ($this->properties[$name]) {
            $this->component->$name = $value;
        } else {
            $this->$name = $value;
        }
    }

    public function __isset($name) {
        if (!isset($this->properties[$name])) {
            $this->properties[$name] = property_exists($this->component, $name);
        }

        if ($this->properties[$name]) {
            return isset($this->component->$name);
        }
    }

    public function __unset($name) {
        if (!isset($this->properties[$name])) {
            $this->properties[$name] = property_exists($this->component, $name);
        }

        if ($this->properties[$name]) {
            unset($this->component->$name);
        }
    }
}