Edit report at https://bugs.php.net/bug.php?id=50559&edit=1
ID: 50559
Updated by: kalle@php.net
Reported by: sr at emini dot dk
Summary: Clone is not implemented for DateInterval and
DatePeriod
-Status: Assigned
+Status: Open
Type: Bug
Package: Date/time related
Operating System: Fedora 10
PHP Version: 5.3.1
-Assigned To: derick
+Assigned To:
Block user comment: N
Private report: N
Previous Comments:
------------------------------------------------------------------------
[2017-06-30 21:49:09] anatoliy at ukhvanovy dot name
Also, if you don't wanna deal with manual coping all the fields like in example above, you may
copy a \DateInterval object indirectly, using the inverse operations \DateTime::add() and
\DateTime::diff() as shown below:
<?php
class CloneDateInterval
{
/**
* @var \DateTime
*/
private static $midnight;
private static function getMidnight(): \DateTime
{
if (self::$midnight === null) {
self::$midnight = new \DateTime('midnight');
}
return clone self::$midnight;
}
public static function makeClone(\DateInterval $dateInterval): \DateInterval
{
return self::getMidnight()->diff(self::getMidnight()->add($dateInterval));
}
}
?>
Although, maybe this method is not as computationally efficient as the one from above, but it
definitely is an interesting alternative, at least from theoretical point of view. :D
------------------------------------------------------------------------
[2017-05-26 12:47:01] cmb@php.net
Related To: Bug #74639
------------------------------------------------------------------------
[2016-10-30 16:12:33] anatoliy at ukhvanovy dot name
The previous example doesn't work. The cloned copy can be var_export'ed correctly,
that's true. But when you try to add it to a DateTime instance, the datetime won't change
at all. Thus, cloned copies are broken. That's why I use another workaround:
<?php
class CloneDateInterval
{
/**
* @param \DateInterval $originalInstance
* @return \DateInterval
*/
public static function buildClone(\DateInterval $originalInstance) {
$copy = new \DateInterval('P0D');
foreach ($originalInstance as $propertyName => $propertyValue) {
$copy->{$propertyName} = $propertyValue;
}
return $copy;
}
}
?>
This one works fine:
$copy = CloneDateTime::buildClone($originalDateInterval);
$datetime->add($copy); //OK
------------------------------------------------------------------------
[2016-10-30 15:08:43] anatoliy at ukhvanovy dot name
There's a WORKAROUND.
If you var_export the instance, then it won't be empty anymore, and you can clone it. Consider
the following code:
<?php
header('Content-Type:text/plain');
$originalInstance = new DateInterval('P1D');
// Original instance is not initialized yet.
// You cannot clone it now, otherwise you'll get an empty copy.
$copyCreatedBeforeOriginalInstanceIsInitialized =
clone $originalInstance;
echo PHP_EOL, 'This copy is empty: ';
var_export($copyCreatedBeforeOriginalInstanceIsInitialized);
// Now, let's initialize original instance by var_export'ing it.
// We don't want to output the var_export's result -
// it is used only to initialize our instance, not to output it.
$doNotEchoVarExport = true;
var_export($originalInstance, $doNotEchoVarExport);
// That's all! For now, original instance is already initialized,
// and we may clone it â we'll get correct copy.
$copyCreatedAfterOriginalInstanceIsInitialized =
clone $originalInstance;
// Now, let's see what we've got:
echo PHP_EOL, 'Original instance is OK: ';
var_export($originalInstance);
echo PHP_EOL, 'Empty copy is still empty: ';
var_export($copyCreatedBeforeOriginalInstanceIsInitialized);
echo PHP_EOL, 'Correct copy is OK: ';
var_export($copyCreatedAfterOriginalInstanceIsInitialized);
// DateInterval behaves like Schrödinger's cat:
// the action of observation affects the phenomenon being observed.
// (var_export'ing the state of DateInterval affects its state.)
?>
The code above produces the following output:
This copy is empty: DateInterval::__set_state(array(
))
Original instance is OK: DateInterval::__set_state(array(
'y' => 0,
'm' => 0,
'd' => 1,
'h' => 0,
'i' => 0,
's' => 0,
'weekday' => 0,
'weekday_behavior' => 0,
'first_last_day_of' => 0,
'invert' => 0,
'days' => false,
'special_type' => 0,
'special_amount' => 0,
'have_weekday_relative' => 0,
'have_special_relative' => 0,
))
Empty copy is still empty: DateInterval::__set_state(array(
))
Correct copy is OK: DateInterval::__set_state(array(
'y' => 0,
'm' => 0,
'd' => 1,
'h' => 0,
'i' => 0,
's' => 0,
'weekday' => 0,
'weekday_behavior' => 0,
'first_last_day_of' => 0,
'invert' => 0,
'days' => false,
'special_type' => 0,
'special_amount' => 0,
'have_weekday_relative' => 0,
'have_special_relative' => 0,
))
------------------------------------------------------------------------
[2013-08-07 20:09:36] kofkof at laposte dot net
If I swap lines 2 and 3 in the bug description code, this way:
$dateInterval1 = new DateInterval('P1D');
var_dump($dateInterval1);
$dateInterval2 = clone $dateInterval1;
var_dump($dateInterval2);
... then $dateInterval2 is not empty (as displayed by var_dump()). However, when
I try to use it:
$d = new DateTime();
$d->add($dateInterval2);
... then I get "Warning: DateTime::add(): The DateInterval object has not been
correctly initialized by its constructor in..."
(PHP 5.4.11 on Mac OS 10.7.5)
------------------------------------------------------------------------
The remainder of the comments for this report are too long. To view
the rest of the comments, please view the bug report online at
https://bugs.php.net/bug.php?id=50559
--
Edit this bug report at https://bugs.php.net/bug.php?id=50559&edit=1