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Date: Wed, 09 Nov 2005 15:06:55 -0800
To: "Thies C. Arntzen" <thies@thieso.net>,internals@lists.php.net
Cc: Thies Arntzen <thies@thieso.net>
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Subject: Re: [PHP-DEV] object-overloading: why not allow recursive
	calls? (5.1)  hey,  in zend_object_handlers.c function
	zend_std_read_property we protect against calling the __get function
	of an object if we're already in a __get() function. (look for 
From: andi@zend.com (Andi Gutmans)

Thies,

I think I might be wrong in my analysis. Seems like the problem is 
worse than what I thought as it seems to cross boundaries between classes.
We'll look into it more.

Andi

At 02:15 PM 11/9/2005, Andi Gutmans wrote:
>This is intentional and I think it makes it much more fool-proof for 
>developers. Adding recursion protection can be very expensive and 
>complicated, and it doesn't seem to make sense here. The idea is 
>that once you're in the __get() method, you know exactly how your 
>properties are mapped and can do the right thing. It's only this one 
>method where you have your mapping anyway, not an entirely different place.
>
>Andi
>
>At 12:35 AM 11/4/2005, Thies C. Arntzen wrote:
>>hey,
>>
>>in zend_object_handlers.c function zend_std_read_property we protect
>>against calling the __get function of an object if we're already in a
>>__get() function. (look for zobj->in_get) in that function.
>>
>>i don't think we should be doing this.
>>
>>simplyfied example:
>><?php
>>class test {
>>     function __get($offset) {
>>         echo "__get($offset)\n";
>>         switch ($offset) {
>>             case 'name': return "name";
>>             case 'length': return strlen($this->name);
>>         }
>>     }
>>}
>>
>>$a = new test;
>>var_dump($a->length);
>>?>
>>
>>outputs:
>>__get(length)
>>int(0)
>>
>>but should say:
>>__get(length)
>>__get(name)
>>int(4)
>>
>>i think recursive gets are highly useful and should be allowed. if we
>>really want to protect against recursion (here) we have two real
>>options: -a- protect against __get(ing) the same property more than
>>once in the same call-chain (mucho work), or -b- (preferred) have
>>some global infinite recursion protection in the engine (needs to be
>>done somewhen anyhow, but not now).
>>
>>so, in one sentence: as we don't protect against recustion elsewhere,
>>can we please remove this unneded roadblock?
>>
>>opinions?
>>-thies
>>
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