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Cc: PHP Developers Mailing List <internals@lists.php.net>,
	Jan Borsodi <jb@ez.no>, Raymond Bosman <rb@ez.no>,
	Frederik Holljen <fh@ez.no>, Tobias Schlitt <ts@ez.no>
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Date: Wed, 3 Aug 2005 16:52:50 -0700
To: Derick Rethans <dr@ez.no>
Subject: Re: [PHP-DEV] Property Overloading RFC
From: andrei@gravitonic.com (Andrei Zmievski)

On Aug 2, 2005, at 6:05 AM, Derick Rethans wrote:

> Solutions:
> - For problem 1. we can introduce a keyword (or use an existing  
> one) to define
>   that it is a virtual property ('abstract' or 'virtual' come to  
> mind). When
>   declaring it like this it's easy to document, and we can also  
> implement
>   visibility for those virtual properties.  Marcus already has a  
> patch for
>   this somewhere, which uses the "abstract" keyword for this purpose:
>
> <?php
> class Base
> {
>     /**
>      * @var int   Contains all X
>      */
>     abstract public $x = 1;
>
>     /**
>      * @var int   Contains all Y
>      */
>     abstract protected $y = 2;
>
>     //  abstract private $z = 3; abstract properties cannot be private
> }
> ?>

The whole point of these "virtual" properties is that their names can  
be parameterized. If you have 1000 of these variables (in a DB or  
somewhere), how would you declare them as "abstract" or "virtual"?

>   This is ofcourse overly complicated. A better workable solution  
> would be -
>   without breaking BC (suggestions for syntax here are very welcome):
>
> <?php
> class Base
> {
>     abstract public $x = 1;
>
>     function __get($name)
>     {
>         if (!self::isVirtual($name))) {
>             /* throw error */
>         }
>     }
> }
>
> $b = new Base();
> echo $b->foo;
> ?>

How about a __have_prop() method that you can call to find out if a  
certain virtual property exists?

-Andrei