SplObjectStorage::detach

(PHP 5 >= 5.1.0, PHP 7)

SplObjectStorage::detachオブジェクトをストレージから取り除く

説明

public SplObjectStorage::detach ( object $object ) : void

オブジェクトをストレージから取り除きます。

パラメータ

object

取り除きたいオブジェクト。

返り値

値を返しません。

例1 SplObjectStorage::detach() の例

<?php
$o 
= new StdClass;
$s = new SplObjectStorage();
$s->attach($o);
var_dump(count($s));
$s->detach($o);
var_dump(count($s));
?>

上の例の出力は、 たとえば以下のようになります。

int(1)
int(0)

参考

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User Contributed Notes 3 notes

up
8
r dot wilczek at web-appz dot de
9 years ago
Detaching the current entry from the storage prevents SplObjectStorage::next() to operate.

Example as a PHPUnit-test:

<?php
public function testDetachingCurrentPreventsNext()
{
   
$storage = new SplObjectStorage;
   
$storage->attach(new stdClass);
   
$storage->attach(new stdClass);
   
$storage->rewind();
   
$iterated = 0;
   
$expected = $storage->count();
    while (
$storage->valid()) {
       
$iterated++;
       
$storage->detach($storage->current());
       
$storage->next();
    }
   
$this->assertEquals($expected, $iterated);
}
?>

This test will fail, for the iteration will never reach the second stdClass.
SplObjectStorage::next() obviously relies on the current element to be valid.

If you want to detach objects during iterations, you should dereference objects, before you call next() and detach the reference after next():

<?php
public function testDetachingReferenceAfterNext()
{
   
$storage = new SplObjectStorage;
   
$storage->attach(new stdClass);
   
$storage->attach(new stdClass);
   
$storage->rewind();
   
$iterated = 0;
   
$expected = $storage->count();
    while (
$storage->valid()) {
       
$iterated++;
       
$object = $storage->current();
       
$storage->next();
       
$storage->detach($object);
    }
   
$this->assertEquals($expected, $iterated);
}
?>

This test will pass.
up
4
alan dot bem at gmail dot com
6 years ago
SplObjectSotage::detach() has a bug - it rewinds internal array pointer.
Remember that - when looping over the storage - as it has no workaround.

https://bugs.php.net/bug.php?id=65629&edit=2
up
0
Hayley Watson
1 year ago
No complaints from SplObjectStorage if you try to detach an object that isn't in the collection; it's a no-op.

<?php

$o
= new StdClass;
$t = new StdClass;
$s = new SplObjectStorage();
$s->attach($o);
var_dump(count($s));
$s->detach($t); // Didn't attach this one.
var_dump(count($s));

?>
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