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Subject: Re: [PHP-DEV] new overloading feature?
From: php@hristov.com (Andrey Hristov)

  Why not using Singleton for multiple objects with getInstance() ?

Andrey

Derrell.Lipman@UnwiredUniverse.com wrote:
> I came across an interesting desire today.  I'd like to create a new class
> instance if an only if a "key" value does not already exist.  This key value
> could be looked up in a database, in an array, etc.
> 
> The following contrived example shows use of a proposed __new() overload
> function which would be called BEFORE the constructor, and could chose to
> return a newly constructed object (by calling __construct()) or to return an
> already existing object.
> 
> One could certainly call a function which searched for the key value and only
> instantiated a new object if the existing one was not found, but this seems
> cleaner.
> 
> Thoughts?
> 
> <?php
> 
> class X
> {
>     static          $allX = array();
>     var             $val;
> 
>     function __construct($val)
>     {
>         $this->val = $val;
>         X::$allX[] =& $this;
>     }
> 
>     function __new($val)
>     {
>         foreach (X::$allX as $x)
>         {
>             if ($x->val == $val)
>             {
>                 return $x;
>             }
>         }
> 
>         return __construct($val);
>     }
> }
> 
> $try1 = new X(23);              /* would return $allX[0] reference */
> $try2 = new X(42);              /* woudl return $allX[1] reference */
> $try3 = new X(23);              /* would return $allX[0] reference */
> ?>
>