/**
* Item lookup function.
*
* This is a separate function to allow overloading by subclasses.
*
* @param scalar $key
* @param mixed $default
* @return mixed
*/
protected function _getItem($key, $default = null)
{
if (is_object($key)) {
$class = get_class($key);
} else {
$class = $key;
}
// Check for simple existence
if ($result = parent::_getItem($class, $default)) {
return $result;
}
// Check was already found
if (array_key_exists($class, $this->_subClasses)) {
return $this->_subClasses[$class];
}
// Check was already searched and not found
if (array_key_exists($class, $this->_notSubClasses)) {
return $default;
}
// Check the parent classes of the object
$parents = class_parents($key);
$result = null;
foreach ($parents as $parentClass) {
if ($result = parent::_getItem($parentClass, null)) {
// Add the current class to the cache
$this->_subClasses[$class] = $result;
// Add all parents up to the one matching to the cache
foreach ($parents as $priorParent) {
$this->_subClasses[$priorParent] = $result;
if ($parentClass === $priorParent) {
// Further parents are not automatically in the list
break;
}
}
return $result;
}
}
// Check the interfaces implemented by the object
$implemented = class_implements($key);
foreach ($implemented as $interface) {
if ($result = parent::_getItem($interface, null)) {
// Add the current class to the cache
$this->_subClasses[$class] = $result;
return $result;
}
}
// Add to the not found cache
$this->_notSubClasses[$class] = true;
return $default;
}
