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Date: Sat, 26 May 2007 14:11:12 +0200
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To: Marco Kaiser <marco.kaiser@gmail.com>
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Subject: Re: [PHP-DEV] $var::$static (and $className::$staticVar)
From: bart@mediawave.nl (Bart de Boer)


I understand... My suggestion would be to map $this to the class name 
(of the current instance) if the Scope Resolution Operator '::' is used...


Marco Kaiser wrote:
> Hi,
>
> this doesnt work because static vars are bound to his class and are not
> inherited by a child class.
> maybe this would be work with php6 or a other 5.x version.
> (Same behavior like the singleton pattern getInstance() abstract class
> stuff)
>
> -- Marco
>   
>> Hi all,
>>
>> I'd like to be able to do the following:
>>
>>
>> <?php
>>
>> class Base {
>>
>>     public static $var = 'hello';
>>
>>     public function someFunc() {
>>         echo self::$var; // Currently maps to Base::$var
>>         echo $this::$var; // Should map to Child::$var
>>     }
>>
>> }
>>
>> class Child extends Base {
>>
>>     public static $var = 'hello';
>>
>> }
>>
>> $class = 'Child';
>>
>> $obj = new $class(); // This works.
>>
>> echo $class::$var; // This doesn't. Should map to Child::$var
>>
>>
>> ?>
>>
>>
>> ...in other words: I'd like to be able to access static class
>> variables from inside an instance of the Base and/or Child classes.
>> I'd also like to be able to access them dynamically.
>> ($className::$variable)
>>
>> The only way to do this at the moment (to my knowledge at least) is to
>> create functions in the Child class that returns its static variables.
>> The downside of this is that those functions most likely will be very
>> common (in my case they are) and should therefore belong in the base
>> class. Hence: $this::$variable
>>
>> At the moment there is no way to access static variables from outside
>> of the class dynamically. As a workaround for this I'm currently
>> creating a temporary instance (new $type()) to access them dynamically
>> with a __get() function in all the derived child classes.
>>
>> There are ways to do it with class constants and the constant
>> functions. But it's not very elegant and class constants can't hold
>> arrays and/or objects.
>>
>> I have no idea what the implications would be. Just thought it would
>> be a nice addition to the language. :) Hope I didn't overlook some
>> existing PHP feature that already allows me to do this. :|
>>
>>
>> Cheers,
>>
>> Bart de Boer
>>
>>