Posted by Tim Van Wassenhove on 01/14/06 06:36

On 2006-01-14, Oli Filth <catch@olifilth.co.uk> wrote:
> FluffyCat said the following on 14/01/2006 00:20:
>> To add to my growing library of Design Patterns in PHP 5 I have
>> written what I think is a good example of the Singleton Pattern.
>>
>> http://www.fluffycat.com/PHP-Design-Patterns/Singleton/
>>
>
> Unfortunately, this is not a good example of a singleton system.
>
> You have a class (BookSingleton) with a public constructor, so there's
> nothing to stop someone creating multiple BookSingleton objects with
> multiple "new BookSingleton()" calls.
>
> To solve this problem, you need to make the constructor private, and the
> borrowBook() method static.

And make sure to throw an error when clone is called.. Because a singleton
shouldn't be cloned :)

--
Met vriendelijke groeten,
Tim Van Wassenhove <http://timvw.madoka.be>

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