Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:45581
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: error (pb1.pair.com: domain garfieldtech.com from 69.5.8.4 cause and error)
To: internals@lists.php.net
Date: Wed, 16 Sep 2009 20:47:45 -0500
User-Agent: KMail/1.11.2 (Linux/2.6.27-14-generic; KDE/4.2.2; i686; ; )
References: <fc.00870cc1051f613f00870cc1051f613f.51f6c07@csisd.org>
In-Reply-To: <fc.00870cc1051f613f00870cc1051f613f.51f6c07@csisd.org>
MIME-Version: 1.0
Content-Type: Text/Plain;
  charset="iso-8859-15"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-ID: <200909162047.45365.larry@garfieldtech.com>
Subject: Re: [PHP-DEV] reference caller object
From: larry@garfieldtech.com (Larry Garfield)

If the object needs to behave differently based on who called it, there's 
already a very easy way to do that:

class A {
  function foo() {
    $b = new B();
    $b->bar($this);
  }
}

class B {
  function bar($caller) {
    if ($caller instance of A) {
       // ...
    }
  }
}

That's also therefore much more self-documenting and easier to test (because 
you can simulate what gets passed in) than a magic keyword.  I don't see a 
need for new magic constants here.

On Wednesday 16 September 2009 3:59:16 pm Chris Trahey wrote:
> (Please direct me elsewhere if necessary, this is a feature request)
>
> It would be handy to allow a method to behave differently based on who is
> calling it.
> the function I am looking for would essentially do this:
>
> function getCaller(){
> 	$bt = debug_backtrace();
> 	return $bt[2]['object'];
> }
> But of course, there is a lot of uneccessary processing with that call.
> Perhaps it could be implimented similar to "self" and "parent" (actualy
> more like "static") keywords.
>
> So you could do:
> public function registerMe() {
> 	if( ! (caller instanceof 'my_interface')) throw new dev_execption();
> 	if( ! ($this->authenticateMod(caller))) throw new admin_exception('module
> not active');
> 	$this->loadedMods[caller->module_id()] = caller;
> 	return caller->onLoad();
> }
>
> Chris Trahey
> Web Applications Developer
> Database Administrator
> CSISD [Technology]

-- 
Larry Garfield
larry@garfieldtech.com