box-o-sand/PracticingPhp/web-cake/html/cake/libs/class_registry.php

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2011-01-03 04:24:59 +00:00
<?php
/**
* Class collections.
*
* A repository for class objects, each registered with a key.
*
* PHP versions 4 and 5
*
* CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
* Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
*
* Licensed under The MIT License
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright 2005-2010, Cake Software Foundation, Inc. (http://cakefoundation.org)
* @link http://cakephp.org CakePHP(tm) Project
* @package cake
* @subpackage cake.cake.libs
* @since CakePHP(tm) v 0.9.2
* @license MIT License (http://www.opensource.org/licenses/mit-license.php)
*/
/**
* Class Collections.
*
* A repository for class objects, each registered with a key.
* If you try to add an object with the same key twice, nothing will come of it.
* If you need a second instance of an object, give it another key.
*
* @package cake
* @subpackage cake.cake.libs
*/
class ClassRegistry {
/**
* Names of classes with their objects.
*
* @var array
* @access private
*/
var $__objects = array();
/**
* Names of class names mapped to the object in the registry.
*
* @var array
* @access private
*/
var $__map = array();
/**
* Default constructor parameter settings, indexed by type
*
* @var array
* @access private
*/
var $__config = array();
/**
* Return a singleton instance of the ClassRegistry.
*
* @return ClassRegistry instance
* @access public
*/
function &getInstance() {
static $instance = array();
if (!$instance) {
$instance[0] =& new ClassRegistry();
}
return $instance[0];
}
/**
* Loads a class, registers the object in the registry and returns instance of the object.
*
* Examples
* Simple Use: Get a Post model instance ```ClassRegistry::init('Post');```
*
* Exapanded: ```array('class' => 'ClassName', 'alias' => 'AliasNameStoredInTheRegistry', 'type' => 'TypeOfClass');```
*
* Model Classes can accept optional ```array('id' => $id, 'table' => $table, 'ds' => $ds, 'alias' => $alias);```
*
* When $class is a numeric keyed array, multiple class instances will be stored in the registry,
* no instance of the object will be returned
* {{{
* array(
* array('class' => 'ClassName', 'alias' => 'AliasNameStoredInTheRegistry', 'type' => 'TypeOfClass'),
* array('class' => 'ClassName', 'alias' => 'AliasNameStoredInTheRegistry', 'type' => 'TypeOfClass'),
* array('class' => 'ClassName', 'alias' => 'AliasNameStoredInTheRegistry', 'type' => 'TypeOfClass')
* );
* }}}
* @param mixed $class as a string or a single key => value array instance will be created,
* stored in the registry and returned.
* @param string $type TypeOfClass
* @return object instance of ClassName
* @access public
* @static
*/
function &init($class, $type = null) {
$_this =& ClassRegistry::getInstance();
$id = $false = false;
$true = true;
if (!$type) {
$type = 'Model';
}
if (is_array($class)) {
$objects = $class;
if (!isset($class[0])) {
$objects = array($class);
}
} else {
$objects = array(array('class' => $class));
}
$defaults = isset($_this->__config[$type]) ? $_this->__config[$type] : array();
$count = count($objects);
foreach ($objects as $key => $settings) {
if (is_array($settings)) {
$pluginPath = null;
$settings = array_merge($defaults, $settings);
$class = $settings['class'];
list($plugin, $class) = pluginSplit($class);
if ($plugin) {
$pluginPath = $plugin . '.';
}
if (empty($settings['alias'])) {
$settings['alias'] = $class;
}
$alias = $settings['alias'];
if ($model =& $_this->__duplicate($alias, $class)) {
$_this->map($alias, $class);
return $model;
}
if (class_exists($class) || App::import($type, $pluginPath . $class)) {
${$class} =& new $class($settings);
} elseif ($type === 'Model') {
if ($plugin && class_exists($plugin . 'AppModel')) {
$appModel = $plugin . 'AppModel';
} else {
$appModel = 'AppModel';
}
$settings['name'] = $class;
${$class} =& new $appModel($settings);
}
if (!isset(${$class})) {
trigger_error(sprintf(__('(ClassRegistry::init() could not create instance of %1$s class %2$s ', true), $class, $type), E_USER_WARNING);
return $false;
}
if ($type !== 'Model') {
$_this->addObject($alias, ${$class});
} else {
$_this->map($alias, $class);
}
} elseif (is_numeric($settings)) {
trigger_error(__('(ClassRegistry::init() Attempted to create instance of a class with a numeric name', true), E_USER_WARNING);
return $false;
}
}
if ($count > 1) {
return $true;
}
return ${$class};
}
/**
* Add $object to the registry, associating it with the name $key.
*
* @param string $key Key for the object in registry
* @param mixed $object Object to store
* @return boolean True if the object was written, false if $key already exists
* @access public
* @static
*/
function addObject($key, &$object) {
$_this =& ClassRegistry::getInstance();
$key = Inflector::underscore($key);
if (!isset($_this->__objects[$key])) {
$_this->__objects[$key] =& $object;
return true;
}
return false;
}
/**
* Remove object which corresponds to given key.
*
* @param string $key Key of object to remove from registry
* @return void
* @access public
* @static
*/
function removeObject($key) {
$_this =& ClassRegistry::getInstance();
$key = Inflector::underscore($key);
if (isset($_this->__objects[$key])) {
unset($_this->__objects[$key]);
}
}
/**
* Returns true if given key is present in the ClassRegistry.
*
* @param string $key Key to look for
* @return boolean true if key exists in registry, false otherwise
* @access public
* @static
*/
function isKeySet($key) {
$_this =& ClassRegistry::getInstance();
$key = Inflector::underscore($key);
if (isset($_this->__objects[$key])) {
return true;
} elseif (isset($_this->__map[$key])) {
return true;
}
return false;
}
/**
* Get all keys from the registry.
*
* @return array Set of keys stored in registry
* @access public
* @static
*/
function keys() {
$_this =& ClassRegistry::getInstance();
return array_keys($_this->__objects);
}
/**
* Return object which corresponds to given key.
*
* @param string $key Key of object to look for
* @return mixed Object stored in registry or boolean false if the object does not exist.
* @access public
* @static
*/
function &getObject($key) {
$_this =& ClassRegistry::getInstance();
$key = Inflector::underscore($key);
$return = false;
if (isset($_this->__objects[$key])) {
$return =& $_this->__objects[$key];
} else {
$key = $_this->__getMap($key);
if (isset($_this->__objects[$key])) {
$return =& $_this->__objects[$key];
}
}
return $return;
}
/**
* Sets the default constructor parameter for an object type
*
* @param string $type Type of object. If this parameter is omitted, defaults to "Model"
* @param array $param The parameter that will be passed to object constructors when objects
* of $type are created
* @return mixed Void if $param is being set. Otherwise, if only $type is passed, returns
* the previously-set value of $param, or null if not set.
* @access public
* @static
*/
function config($type, $param = array()) {
$_this =& ClassRegistry::getInstance();
if (empty($param) && is_array($type)) {
$param = $type;
$type = 'Model';
} elseif (is_null($param)) {
unset($_this->__config[$type]);
} elseif (empty($param) && is_string($type)) {
return isset($_this->__config[$type]) ? $_this->__config[$type] : null;
}
$_this->__config[$type] = $param;
}
/**
* Checks to see if $alias is a duplicate $class Object
*
* @param string $alias
* @param string $class
* @return boolean
* @access private
* @static
*/
function &__duplicate($alias, $class) {
$duplicate = false;
if ($this->isKeySet($alias)) {
$model =& $this->getObject($alias);
if (is_object($model) && (is_a($model, $class) || $model->alias === $class)) {
$duplicate =& $model;
}
unset($model);
}
return $duplicate;
}
/**
* Add a key name pair to the registry to map name to class in the registry.
*
* @param string $key Key to include in map
* @param string $name Key that is being mapped
* @access public
* @static
*/
function map($key, $name) {
$_this =& ClassRegistry::getInstance();
$key = Inflector::underscore($key);
$name = Inflector::underscore($name);
if (!isset($_this->__map[$key])) {
$_this->__map[$key] = $name;
}
}
/**
* Get all keys from the map in the registry.
*
* @return array Keys of registry's map
* @access public
* @static
*/
function mapKeys() {
$_this =& ClassRegistry::getInstance();
return array_keys($_this->__map);
}
/**
* Return the name of a class in the registry.
*
* @param string $key Key to find in map
* @return string Mapped value
* @access private
* @static
*/
function __getMap($key) {
if (isset($this->__map[$key])) {
return $this->__map[$key];
}
}
/**
* Flushes all objects from the ClassRegistry.
*
* @return void
* @access public
* @static
*/
function flush() {
$_this =& ClassRegistry::getInstance();
$_this->__objects = array();
$_this->__map = array();
}
}