ID: 42937
Updated by: [EMAIL PROTECTED]
Reported By: jmaxwilson at sixteensmallstones dot org
-Status: Open
+Status: Assigned
Bug Type: Scripting Engine problem
Operating System: Windows XP
PHP Version: 5.2.4
-Assigned To:
+Assigned To: dmitry
New Comment:
I think parent:: should use __call, since it's not in fact a static
call.
Previous Comments:
------------------------------------------------------------------------
[2007-10-12 21:46:43] jmaxwilson at sixteensmallstones dot org
Thanks for the feedback. However, adding a magic __callstatic() method
doesn't actually fix the problem. I think there is some
misunderstanding about the scope resolution operator (::). While it is
often used to access the static methods of a class, when applied to the
keyword "parent" it is used to access the _instance_ methods of a the
parent class. So, calling parent::getVersion() is calling the _instance_
method of the parent from the child class, not a static method. Why is
this important? What if the method needs to get or set properties of the
instance? It must be an instance method. The $this pseudo-variable is
not even available within static methods.
To illustrate, the example code can be modified like this:
<?php
class A {
var $arrValues = array();
function __construct() {
$this->arrValues['PHP'] = "PHP " . phpversion();
}
function __call($strMethod, $arrArgs) {
return $this->arrValues['PHP'];
}
}
class B extends A {
function getVersion() {
return parent::getVersion() . " Rocks!";
}
}
$A = new A();
echo $A->getVersion() . "<br/>";
$B = new B();
echo $B->getVersion() . "<br/>";
?>
It would be incorrect for the engine to call the __callstatic() magic
method when a child class calls a parent's method. I hope that is not
what 5_3 does.
------------------------------------------------------------------------
[2007-10-12 10:11:04] judas dot iscariote at gmail dot com
This is fixed in 5_3 but you have to define __callstatic like this
<?php
class A {
function __call($strMethod, $arrArgs) {
return "PHP " .phpversion();
}
static function __callstatic($strMethod, $arrArgs)
{
return "PHP " .phpversion();
}
}
class B extends A {
function getVersion() {
return parent::getVersion() . " Rocks!";
}
}
$A = new A();
echo $A->getVersion() . "<br/>";
$B = new B();
echo $B->getVersion() . "<br/>";
?>
------------------------------------------------------------------------
[2007-10-11 23:08:54] jmaxwilson at sixteensmallstones dot org
Description:
------------
If __call() is used to implement a method in a parent class, and the
method is overridden in an inherited child class using a real method
declaration that calls parent::methodName(), __call() is never invoked
and PHP reports a fatal error saying that the method is undefined.
You can work around the bug by replacing parent::methodName() with
parent::__call('methodName',null), but it means that you have to know
which of the parent's methods are implemented using __call() in order to
override them in a child class.
The child class should be agnostic to whether the parent's methods are
real or magic.
This bug was reported in PHP5.1 RC1
(http://bugs.php.net/bug.php?id=34739) but was improperly marked as
bogus with the explanation that "__call() is not used when calling
static methods." The use of the paamayim-nekudotayim (::) with the
parent keyword is not to resolve static scope but to resolve inherited
scope for an overridden method, therefore the issue should be
reconsidered.
Reproduce code:
---------------
<?php
class A {
function __call($strMethod, $arrArgs) {
return "PHP " .phpversion();
}
}
class B extends A {
function getVersion() {
return parent::getVersion() . " Rocks!";
}
}
$A = new A();
echo $A->getVersion() . "<br/>";
$B = new B();
echo $B->getVersion() . "<br/>";
?>
Expected result:
----------------
PHP 5.2.4
PHP 5.2.4 Rocks!
Actual result:
--------------
PHP 5.2.4
Fatal error: Call to undefined method A::getversion() in
C:\www\test.php on line 10
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=42937&edit=1
