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Date: Sat, 26 May 2007 15:36:55 +0200
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To: Bart de Boer <bart@mediawave.nl>, internals@lists.php.net
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Subject: Re: [PHP-DEV] $var::$static
From: info@adaniels.nl (Arnold Daniels)

Hi,

I agree that $this::$var isn't really logical, since $this is an object 
and not a class name. But I do not see why $class::$var shouldn't work, 
or $class::$method() for that method. You can also do $function().

Also I want to suggest that brackets can be used more freely. Currently 
you can use ${$group . '_myvar'}, but you can't do the same for 
functions and classes. It would be great if you could use {$group . '_' 
. $fn}() and {get_class($this)}::$var.

The way to solve this problems right now is to use eval('return ' . 
get_class($this) . '::$var;') for getting the value. Getting a reference 
to the variable to set it, is even more messy. You need to do something 
like eval('$cvar =& ' . get_class($this) . '::$var;'); $cvar = 'bye';.

Anyway, it is not so nice, but doable in user space fairly easily. So I 
don't see why anything needs to be added in PHP 5. It would be nice to 
have a better method in PHP 6 though.

 From Holland with love,
Arnold


Bart de Boer wrote:
>
> I seem to have been a bit too hasty with my previous reply... You 
> meant it wouldn't be able to access the static vars of the inherited 
> Base class?... I think that's a different feature regarding the static 
> access mechanism currently already in place... I'm only suggesting the 
> ability to reference classes dynamically some way...
>
> -- Bart
>
>
> 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
>>>
>
>> 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
>>>
>