Edit report at https://bugs.php.net/bug.php?id=51622&edit=1
ID: 51622
Comment by: me at achronos dot ca
Reported by: oliver dot graetz at gmx dot de
Summary: ArrayObject::offsetGet should return a reference
Status: Open
Type: Feature/Change Request
Package: SPL related
PHP Version: 5.2.13
Block user comment: N
Private report: N
New Comment:
Although no php dev has ever mentioned it in a bug report (that I can find), this issue has in fact
been fixed.
At least, it has been fixed for ArrayAccess.
For ArrayObject, I haven't tested.
According to the PHP docs (http://php.net/manual/en/arrayaccess.offsetget.php notes section)
this was fixed in 5.3.4 by relaxing the requirements for implementing AccessAccess, so that
public function &offsetGet($offset) {}
works, and thus indirect access works.
I've confirmed this does in fact work (on 5.3.8).
There are multiple bug reports all related to this topic:
https://bugs.php.net/bug.php?id=51622
https://bugs.php.net/bug.php?id=34783
https://bugs.php.net/bug.php?id=32983
Previous Comments:
------------------------------------------------------------------------
[2011-02-18 23:35:18] urkle at outoforder dot cc
Is this issue fixed in PHP 5.3.4 which supports defining &offsetGet ? (As documented in http://php.net/manual/en/arrayaccess.offsetget.php
)
Actually Just tested and it's not.. Though ArrayAccess by itself works wonderfully.
--- Test script (Tested on PHP 5.3.5 x86_64 on Fedora 14)
<?php
class Test implements ArrayAccess {
private $data = array();
/** Array Access */
public function offsetExists($offset)
{
return isset($this->data[$offset]);
}
public function &offsetGet($offset)
{
return $this->data[$offset];
}
public function offsetSet($offset, $value)
{
$this->data[$offset] = $value;
}
public function offsetUnset($offset)
{
unset($this->data[$offset]);
}
}
class Test2 extends ArrayObject {
public function &offsetGet($offset)
{
$t =& parent::offsetGet($offset);
return $t;
}
}
$t = new Test();
$t['test'] = array(1,2,3,4);
echo serialize($t)."\n";
$t['test'][] = 5;
echo serialize($t)."\n";
$t = new Test2();
$t['test'] = array(1,2,3,4);
echo serialize($t)."\n";
$t['test'][] = 5;
echo serialize($t)."\n";
------------------------------------------------------------------------
[2010-08-18 10:21:25] golgote at mamasam dot com
I'd like to see a solution to this problem as well. I have spent countless hours
trying to use ArrayObject and ArrayAccess and they both have problems either
with get and unset. An unset() on an ArrayObject issues the notice :
$object["list"][0]["prods"] = "1,3";
$object["list"][0]["cache"][1] = array(
'name' => 'p3',
'categories' => array(
array('category' => 'c3'),
),
'price' => 3
);
unset($object["list"][0]["cache"][2]);
will issue Notice: Indirect modification of overloaded element... while this
works with ArrayAccess!
But something like a straight :
$object['arr'][0]['foo'] = 'bar';
will issue the notice with ArrayAccess but not with an ArrayObject!
It's really silly.
I suggest that since this bug hasn't been fixed since 2005, it should be
documented clearly that neither ArrayAccess and ArrayObject work correctly with
multidimensional arrays and are just quick, funny but useless hacks so that
people stop wasting their time with them.
------------------------------------------------------------------------
[2010-06-03 23:32:03] andrewm dot finewolf at gmail dot com
Arrays in PHP contains references to primitive types and reference types. Which basically means that
if you are post-incrementing an element, well, it actually works.
Why is ArrayAccess::offsetGet() returns by value instead of by reference? Wasn't ArrayAccess
created to emulate an array? This is a major inconsistency in the platform and makes this whole
interface pretty useless. This isn't an engine limitation. __get(), __set(), __isset(),
__unset() is returning values by reference without any problems. Why can't ArrayAccess (when it
does pretty much the same thing?)
Can ArrayAccess::offsetGet() return by reference (or at the very least create a second interface,
"ArrayAccessRef", for this)?
------------------------------------------------------------------------
[2010-04-27 10:02:34] colder@php.net
This is actually a feature request. To be backward compatible, we would need to
have a new interface, and obviously a new interface only to solve that reference
thing is painful.
The immediate solution is to return an ArrayObject itself, which means that
indirect modifications will work.
------------------------------------------------------------------------
[2010-04-21 13:35:50] oliver dot graetz at gmx dot de
Description:
------------
This bug refers to my report filed under http://bugs.php.net/bug.php?id=34783 which is now
more than four years old. In the meantime I found out that using ArrayObject instead of the test
class the
$t['huba'][]='three';
actually works, thanks to the SPL using its "implemented in C advantage" to circumvent the
problem. Actually, it works until the programmer decides to inherit from ArrayObject and overwrite
offsetGet(). Then the problem of the offsetGet() method not returning by reference is back.
Back in 2005 you were very quick to flag the report as BOGUS, but a look at the source code of
"zend_interfaces.c" proves that there is in fact a problem:
ZEND_BEGIN_ARG_INFO_EX(arginfo_arrayaccess_offset_get, 0, 0, 1) /* actually this should be return by
ref but atm cannot be */
The best way of dealing with this is not to mark it as BOGUS and deny that there is a problem. It
would be admitting the fault and perhaps introducing an alternative NewArrayAccess interface that
defines &offsetGet(). So future code can use it without breaking old implementations.
Test script:
---------------
<?php
class Test1 extends ArrayObject
{
}
class Test2 extends ArrayObject
{
function offsetGet($key) { return parent::offsetGet($key); }
}
$t1 = new Test1();
$t1['huba'] = array('one','two');
$t1['huba'][] = 'three';
print_r($t1);
$t2 = new Test2();
$t2['huba'] = array('one','two');
$t2['huba'][] = 'three';
print_r($t2);
Expected result:
----------------
Test1 Object
(
[huba] => Array
(
[0] => one
[1] => two
[2] => three
)
)
Test2 Object
(
[huba] => Array
(
[0] => one
[1] => two
[2] => three
)
)
Actual result:
--------------
Test1 Object
(
[huba] => Array
(
[0] => one
[1] => two
[2] => three
)
)
Notice: Indirect modification of overloaded element of Test2 has no effect in F:\huba.php on line 17
Test2 Object
(
[huba] => Array
(
[0] => one
[1] => two
)
)
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=51622&edit=1