<?php
/**
* CakePHP(tm) : Rapid Development Framework (https://cakephp.org)
* Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
*
* Licensed under The MIT License
* For full copyright and license information, please see the LICENSE.txt
* Redistributions of files must retain the above copyright notice.
*
* @copyright Copyright (c) Cake Software Foundation, Inc. (https://cakefoundation.org)
* @link https://cakephp.org CakePHP(tm) Project
* @since 2.0.0
* @license https://opensource.org/licenses/mit-license.php MIT License
*/
namespace Cake\View;
use Cake\Core\App;
use Cake\Core\ObjectRegistry;
use Cake\Event\EventDispatcherInterface;
use Cake\Event\EventDispatcherTrait;
use Cake\View\Exception\MissingHelperException;
/**
* HelperRegistry is used as a registry for loaded helpers and handles loading
* and constructing helper class objects.
*/
class HelperRegistry extends ObjectRegistry implements EventDispatcherInterface
{
use EventDispatcherTrait;
/**
* View object to use when making helpers.
*
* @var \Cake\View\View
*/
protected $_View;
/**
* Constructor
*
* @param \Cake\View\View $view View object.
*/
public function __construct(View $view)
{
$this->_View = $view;
$this->setEventManager($view->getEventManager());
}
/**
* Tries to lazy load a helper based on its name, if it cannot be found
* in the application folder, then it tries looking under the current plugin
* if any
*
* @param string $helper The helper name to be loaded
* @return bool whether the helper could be loaded or not
* @throws \Cake\View\Exception\MissingHelperException When a helper could not be found.
* App helpers are searched, and then plugin helpers.
*/
public function __isset($helper)
{
if (isset($this->_loaded[$helper])) {
return true;
}
try {
$this->load($helper);
} catch (Exception\MissingHelperException $exception) {
if ($this->_View->getPlugin()) {
$this->load($this->_View->getPlugin() . '.' . $helper);
return true;
}
}
if (!empty($exception)) {
throw $exception;
}
return true;
}
/**
* Provide public read access to the loaded objects
*
* @param string $name Name of property to read
* @return mixed
*/
public function __get($name)
{
if (isset($this->_loaded[$name])) {
return $this->_loaded[$name];
}
if (isset($this->{$name})) {
return $this->_loaded[$name];
}
return null;
}
/**
* Resolve a helper classname.
*
* Part of the template method for Cake\Core\ObjectRegistry::load()
*
* @param string $class Partial classname to resolve.
* @return string|false Either the correct classname or false.
*/
protected function _resolveClassName($class)
{
return App::className($class, 'View/Helper', 'Helper');
}
/**
* Throws an exception when a helper is missing.
*
* Part of the template method for Cake\Core\ObjectRegistry::load()
* and Cake\Core\ObjectRegistry::unload()
*
* @param string $class The classname that is missing.
* @param string $plugin The plugin the helper is missing in.
* @return void
* @throws \Cake\View\Exception\MissingHelperException
*/
protected function _throwMissingClassError($class, $plugin)
{
throw new MissingHelperException([
'class' => $class . 'Helper',
'plugin' => $plugin,
]);
}
/**
* Create the helper instance.
*
* Part of the template method for Cake\Core\ObjectRegistry::load()
* Enabled helpers will be registered with the event manager.
*
* @param string $class The class to create.
* @param string $alias The alias of the loaded helper.
* @param array $settings An array of settings to use for the helper.
* @return \Cake\View\Helper The constructed helper class.
*/
protected function _create($class, $alias, $settings)
{
$instance = new $class($this->_View, $settings);
$enable = isset($settings['enabled']) ? $settings['enabled'] : true;
if ($enable) {
$this->getEventManager()->on($instance);
}
return $instance;
}
}