#36172 [Opn]: subclass serialization of parent private members
| From: | sniper@php.net | Date: | Fri, 27 Jan 2006 07:38:54 +0000 |
| Subject: | #36172 [Opn]: subclass serialization of parent private members | ||
| References: | 1 | Groups: | php.doc |
| Request: | Send a blank email to phpdoc+get-969371748@lists.php.net to get a copy of this message | ||
ID: 36172
Updated by: sniper@php.net
Reported By: php at justin dot meagerman dot net
Status: Open
-Bug Type: Scripting Engine problem
+Bug Type: Documentation problem
Operating System: linux
PHP Version: 5.1.2
New Comment:
reclassified.
Previous Comments:
------------------------------------------------------------------------
[2006-01-26 21:35:58] php at justin dot meagerman dot net
Thank you for the workaround. However, the existence of a workaround
does not invalidate the bug. This is clearly not expected behavior.
Moreover, when __sleep methods are not defined, the behaviour is as
expected, as noted below.
If this really is not a bug, then it needs to be documented in the
__sleep documentation page (and this bug's category should be changed
to reflect that).
<?php
class A {
private $a;
public function __construct() {
$this->a = 'aVal';
}
}
class B extends A {
private $b;
public function __construct() {
parent::__construct();
$this->b = 'bVal';
}
}
$serialB = serialize(new B());
print_r(unserialize($serialB));
?>
outputs:
B Object
(
[b:private] => bVal
[a:private] => aVal
)
------------------------------------------------------------------------
[2006-01-26 20:24:42] helly@php.net
Thank you for taking the time to write to us, but this is not
a bug. Please double-check the documentation available at
http://www.php.net/manual/ and the instructions on how to
report
a bug at http://bugs.php.net/how-to-report.php
Use interface Serializable, see:
$> php --rc Serializable
------------------------------------------------------------------------
[2006-01-26 19:42:57] php at justin dot meagerman dot net
Description:
------------
With a private member defined in a parent class and a subclass which
defines a __sleep method, serialization of instances of the subclass
will not save the parent's private member.
This works as expected if __sleep methods are not defined.
Clearly, because of name conflicts, the child __sleep cannot return the
names of the parent's private members (directly, or indirectly by
calling parent::__sleep), and therefore I think PHP might need to call
__sleep for each class in the hierarchy.
This may be the same issue the no-feedback bug #35779 was trying to
convey.
Reproduce code:
---------------
class A {
private $a;
public function __construct() {
$this->a = 'aVal';
}
public function __sleep() {
return array('a');
}
}
class B extends A {
private $b;
public function __construct() {
parent::__construct();
$this->b = 'bVal';
}
public function __sleep() {
//return array('b');
return array_merge(parent::__sleep(), array('b'));
}
}
$serialB = serialize(new B());
print_r(unserialize($serialB));
Expected result:
----------------
B Object
(
[b:private] => bVal
[a:private] => aVal
)
Actual result:
--------------
Notice: serialize(): "a" returned as member variable from __sleep() but
does not exist in [...]
B Object
(
[b:private] => bVal
[a:private] =>
[a] =>
)
------------------------------------------------------------------------
--
Edit this bug report at http://bugs.php.net/?id=36172&edit=1