PHP: DecoratorAbstract - Allows the creation of flexible nested decorators.

DecoratorAbstract.php

<?php

/**
 * DecoratorAbstract allows the creation of flexible nested decorators. All decorators must extend from this class.
 * Decorators can be stacked. They can also have methods that overwrite each other.
 * Decorators can omit methods that parent decorators have defined and/or child decorators have defined.
 * Methods will cascade to the original child object.
 * Properties will read and set from the original child object except when your instance has the property defined.
 */
abstract class DecoratorAbstract
{

    protected $object;

    /**
     * Gets the original object that all the decorators have wrapped themselves around.
     * @return Object
     */
    public function getOriginalObject()
    {
        $object = $this->object;

        while (is_a($object, get_class())) {
            $object = $object->getOriginalObject();
        }

        return $object;
    }

    /**
     * Magic __call will recursively call itself and cascade through all the methods on the decorators.
     * This will work for the child object's methods, and even when methods are missing in between the decorator stack.
     * @param  String $method
     * @param  array  $args
     * @return Mixed
     */
    public function __call($method, $args)
    {
        return call_user_func_array(array($this->object, $method), $args);
    }

    /**
     * Magic __get will return the properties from the original object.
     * This won't be executed if the current instance has the property defined.
     * @param  String $property
     * @return Mixed
     */
    public function __get($property)
    {
        $object = $this->getOriginalObject();
        if (property_exists($object, $property)) {
            return $object->$property;
        }
        return null;
    }

    /**
     * Magic __set will set a property on the original object.
     * This won't be executed if the current instance has the property defined.
     * @param  String $property
     * @param  Mixed  $value
     * @return void
     */
    public function __set($property, $value)
    {
        $object = $this->getOriginalObject();
        $object->$property = $value;
    }
}