获得“对过载属性的间接修改没有效果".注意 [英] Getting "Indirect modification of overloaded property has no effect" notice
问题描述
我想使用注册表来存储一些对象.这是一个简单的Registry类实现.
I want to use a Registry to store some objects. Here is a simple Registry class implementation.
<?php
final class Registry
{
private $_registry;
private static $_instance;
private function __construct()
{
$this->_registry = array();
}
public function __get($key)
{
return
(isset($this->_registry[$key]) == true) ?
$this->_registry[$key] :
null;
}
public function __set($key, $value)
{
$this->_registry[$key] = $value;
}
public function __isset($key)
{
return isset($this->_registry[$key]);
}
public static function getInstance()
{
if (self::$_instance == null) self::$_instance = new self();
return self::$_instance;
}
}
?>
当我尝试访问此类时，收到间接修改重载属性无效"的通知.
When I try to access this class, I get "Indirect modification of overloaded property has no effect" notification.
Registry::getInstance()->foo = array(1, 2, 3); // Works
Registry::getInstance()->foo[] = 4; // Does not work
我该怎么办?
推荐答案
已多次将此行为报告为错误:
This behavior has been reported as a bug a couple times:
- https://bugs.php.net/bug.php?id=42030
- https://bugs.php.net/bug.php?id=41641
我不清楚讨论的结果是什么，尽管这似乎与按值"和按引用"传递值有关.我在一些类似的代码中找到的解决方案做了一些事情像这样:
It is unclear to me what the result of the discussions was although it appears to have something to do with values being passed "by value" and "by reference". A solution that I found in some similar code did something like this:
function &__get( $index )
{
if( array_key_exists( $index, self::$_array ) )
{
return self::$_array[ $index ];
}
return;
}
function &__set( $index, $value )
{
if( !empty($index) )
{
if( is_object( $value ) || is_array( $value) )
{
self::$_array[ $index ] =& $value;
}
else
{
self::$_array[ $index ] =& $value;
}
}
}
请注意它们如何使用&__get和&__set，以及在分配值时使用& $value.我认为这是使这项工作有效的方法.
Notice how they use &__get and &__set and also when assigning the value use & $value. I think that is the way to make this work.
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