This is occurring because cloning Zend_Config only creates a shallow clone currently.
Solution 1: Cast to an array and create a new instance:
This can be achieved already and effectively creates a deep clone.
$parent = new Zend_Config(array('key' => array('nested' => 'parent')), true); //allow read-write for merging
$newConfig = new Zend_Config($parent->toArray(), true); //cast the parent object to an array and create a new Zend_Config
$newConfig->merge(new Zend_Config(array('key' => array('nested' => 'override')), true));
echo $newConfig->key->nested; // 'override' - as expected
echo $parent->key->nested; // 'parent' - as expected
Solution 2: Fixing Zend_Config to perform a deep clone:
/**
* Perform a deep clone of this instance to allow side-effect free cloning.
* @return void
*/
public function __clone()
{
$data = array();
foreach ($this->_data as $key => $value)
{
if ($value instanceof Zend_Config)
{
$data[$key] = clone $value;
} else {
$data[$key] = $value;
}
}
$this->_data = $data;
}
Gives:
$parent = new Zend_Config(array('key' => array('nested' => 'parent')), true); //allow read-write for merging
$newConfig = clone $parent;
$newConfig->merge(new Zend_Config(array('key' => array('nested' => 'override')), true));
echo $newConfig->key->nested; // 'override' - as expected
echo $parent->key->nested; // 'parent' - as expected
It makes sense to me that this is the expected behaviour when cloning and a deep clone greatly reduces the chance of hard to detect side-effects. Does anybody disagree?
From Daniel Skinner
================
I am getting unexpected behaviour when cloning a Zend_Config object:
Example (actual behaviour):
$parent = new Zend_Config(array('key' => array('nested' => 'parent')), true); //allow read-write for merging
$newConfig = clone $parent;
$newConfig->merge(new Zend_Config(array('key' => array('nested' => 'override')), true));
echo $newConfig->key->nested; // 'override' - as expected
echo $parent->key->nested; // 'override' - I was expecting this to be 'parent'
Intuitive behaviour (what makes sense):
Cloning a Zend_Config object should completely separate the new instance from the original - i.e. there should be no cross-references.
This is occurring because cloning Zend_Config only creates a shallow clone currently.
Solution 1: Cast to an array and create a new instance:
This can be achieved already and effectively creates a deep clone.
$parent = new Zend_Config(array('key' => array('nested' => 'parent')), true); //allow read-write for merging
$newConfig = new Zend_Config($parent->toArray(), true); //cast the parent object to an array and create a new Zend_Config
$newConfig->merge(new Zend_Config(array('key' => array('nested' => 'override')), true));
echo $newConfig->key->nested; // 'override' - as expected
echo $parent->key->nested; // 'parent' - as expected
Solution 2: Fixing Zend_Config to perform a deep clone:
/**
* Perform a deep clone of this instance to allow side-effect free cloning.
* @return void
*/
public function __clone()
{
$data = array();
foreach ($this->_data as $key => $value)
{
if ($value instanceof Zend_Config)
{
$data[$key] = clone $value;
} else {
$data[$key] = $value;
}
}
$this->_data = $data;
}
Gives:
$parent = new Zend_Config(array('key' => array('nested' => 'parent')), true); //allow read-write for merging
$newConfig = clone $parent;
$newConfig->merge(new Zend_Config(array('key' => array('nested' => 'override')), true));
echo $newConfig->key->nested; // 'override' - as expected
echo $parent->key->nested; // 'parent' - as expected
Bug
Resolved
Major
Zend_Config instances should perform deep copy on clone
Resolved on trunk in svn r11113.