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Date: Wed, 18 May 2005 17:27:25 +0100
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To: Wez Furlong <kingwez@gmail.com>
Cc: Lukas Smith <lsmith@php.net>, internals@lists.php.net
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Subject: Re: [PHP-DEV] Re: Allow PDO::query() to return a subclass of PDOStatement
From: nick.telford@ntlworld.com (Nicholas Telford)

Wez Furlong wrote:

>parent::method() should work, but the point is that if you add a foo()
>method in a class that extends PDO, at a time where there is no
>PDO::foo(), and you make it work in a particular way, and 6-18 months
>later, when PDO::foo() gets added and does something totally
>different.  Now, someone else is consuming your library and hasn't yet
>used your foo() implementation, they read the PDO manual and spot the
>official PDO::foo() method and wonder why it doesn't work right.
>
>Even more of a headache is that drivers can magically add methods to
>the namespace; different methods may be present on an instance (via
>call overloading) depending on which driver is in use.  These are not
>visible via reflection.
>
>This is a classic namespacing problem.  We've solved this internally
>be forcing drivers to prefix their methods with the driver name.  Any
>non-prefixed method names are reserved for future use by PDO.
>
>If you don't follow this guideline, your code is officially broken :-)
>
>--Wez.
>
Unless the developer of said library realised this problem and decided 
to prefix all his/her methods with something unique :-P

I understand what you're saying, and it is a bit of a problem, however, 
it's something that other Object-Oriented languages must also suffer 
when users decide to subclass a built in class, or even one from an 
external library. In fact, this problem would be present anywhere where 
someone would be subclassing a class that is not under their direct control.

So I guess the moral of the story is, it's possible, just be careful 
with method naming :-)