OO Magic

I did a bit of research today, and came up with the following interesting method:

class MyClass {
  private $sub_data; // some random object

  public function doSomething() {
    ...
  }

  private function __call($name, $args) {
    if( is_object($this->sub_data) ) {
      return call_user_func(array(&$this->sub_data, $name), $args);
    }
    else {
      echo "Error: sub_data is not an object.  This method was not found\n";
      return;
    }
  }
}

I have a class defined with a property ($this->sub_data) that holds a variable class instance. What the $__call() method allows me to do is to proxy method calls invoked on my "container" class down to the $this->sub_data class without having to know anything about the sub_data object instance.

More info:
Overloading
call_user_func