Hi Richard,
On Thu, Jun 13, 2013 at 10:16 AM, Richard Quadling <rquadling@xxxxxxxxx>wrote:
> I'm building a class which needs to have certain methods called by the
> subclass, but the subclass can extend but not obscure/override the
> behaviour.
>
This is the Template Method pattern, though in this case you could use a
Strategy where the specific authentication implementation is in a separate
class that gets injected into the Auth class. As for your example there a a
few things I would change.
* The template method that the subclass must implement should not be
declared by an interface. Interfaces are for declaring public contracts.
You can simply declare an abstract, protected method in Auth. This is the
contract that every subclass must fulfill.
* I would avoid reference variables as you've indicated. If you don't want
to build a data-holder class yet, simply return an array for now. While you
cannot enforce the return type at parse time, they should be verified with
unit tests. Unit tests are critical with dynamic languages like PHP and
Python since runtime is the only way to verify behavior.
Otherwise, your example is spot on, though the name AuthRequestMade implies
the request has already been made yet I think from your description that
this method should *make* the actual request. Here's how I would write it
with the above in place.
class Auth {
public function MakeAuthRequest() {
// before
$this->MakeAuthRequestImpl(); // Adding "Impl" suffix is a
common convention
// after
}
/**
* Make the actual authentication request.
*
* @return array Must contain keys "state" and "message" to hold
the result
*/
protected abstract function MakeAuthRequestImpl();
}
Peace,
David
