zoneminder/web/lib/Cake/View/HelperCollection.php

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2013-05-01 18:58:31 +08:00
<?php
/**
* Helpers collection is used as a registry for loaded helpers and handles loading
* and constructing helper class objects.
*
* CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
* Copyright (c) Cake Software Foundation, Inc. (http://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. (http://cakefoundation.org)
* @link http://cakephp.org CakePHP(tm) Project
* @package Cake.View
* @since CakePHP(tm) v 2.0
* @license MIT License (http://www.opensource.org/licenses/mit-license.php)
*/
App::uses('ObjectCollection', 'Utility');
App::uses('CakeEventListener', 'Event');
/**
* Helpers collection is used as a registry for loaded helpers and handles loading
* and constructing helper class objects.
*
* @package Cake.View
*/
class HelperCollection extends ObjectCollection implements CakeEventListener {
/**
* View object to use when making helpers.
*
* @var View
*/
protected $_View;
/**
* Constructor
*
* @param View $view
*/
public function __construct(View $view) {
$this->_View = $view;
}
/**
* 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 $helper The helper name to be loaded
* @return boolean whether the helper could be loaded or not
* @throws MissingHelperException When a helper could not be found.
* App helpers are searched, and then plugin helpers.
*/
public function __isset($helper) {
if (parent::__isset($helper)) {
return true;
}
try {
$this->load($helper);
} catch (MissingHelperException $exception) {
if ($this->_View->plugin) {
$this->load($this->_View->plugin . '.' . $helper);
return true;
}
}
if (!empty($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 ($result = parent::__get($name)) {
return $result;
}
if ($this->__isset($name)) {
return $this->_loaded[$name];
}
return null;
}
/**
* Loads/constructs a helper. Will return the instance in the registry if it already exists.
* By setting `$enable` to false you can disable callbacks for a helper. Alternatively you
* can set `$settings['enabled'] = false` to disable callbacks. This alias is provided so that when
* declaring $helpers arrays you can disable callbacks on helpers.
*
* You can alias your helper as an existing helper by setting the 'className' key, i.e.,
* {{{
* public $helpers = array(
* 'Html' => array(
* 'className' => 'AliasedHtml'
* );
* );
* }}}
* All calls to the `Html` helper would use `AliasedHtml` instead.
*
* @param string $helper Helper name to load
* @param array $settings Settings for the helper.
* @return Helper A helper object, Either the existing loaded helper or a new one.
* @throws MissingHelperException when the helper could not be found
*/
public function load($helper, $settings = array()) {
if (is_array($settings) && isset($settings['className'])) {
$alias = $helper;
$helper = $settings['className'];
}
list($plugin, $name) = pluginSplit($helper, true);
if (!isset($alias)) {
$alias = $name;
}
if (isset($this->_loaded[$alias])) {
return $this->_loaded[$alias];
}
$helperClass = $name . 'Helper';
App::uses($helperClass, $plugin . 'View/Helper');
if (!class_exists($helperClass)) {
throw new MissingHelperException(array(
'class' => $helperClass,
'plugin' => substr($plugin, 0, -1)
));
}
$this->_loaded[$alias] = new $helperClass($this->_View, $settings);
$vars = array('request', 'theme', 'plugin');
foreach ($vars as $var) {
$this->_loaded[$alias]->{$var} = $this->_View->{$var};
}
$enable = isset($settings['enabled']) ? $settings['enabled'] : true;
if ($enable) {
$this->enable($alias);
}
return $this->_loaded[$alias];
}
/**
* Returns a list of all events that will fire in the View during it's lifecycle.
*
* @return array
*/
public function implementedEvents() {
return array(
'View.beforeRenderFile' => 'trigger',
'View.afterRenderFile' => 'trigger',
'View.beforeRender' => 'trigger',
'View.afterRender' => 'trigger',
'View.beforeLayout' => 'trigger',
'View.afterLayout' => 'trigger'
);
}
/**
* Trigger a callback method on every object in the collection.
* Used to trigger methods on objects in the collection. Will fire the methods in the
* order they were attached.
*
* ### Options
*
* - `breakOn` Set to the value or values you want the callback propagation to stop on.
* Can either be a scalar value, or an array of values to break on. Defaults to `false`.
*
* - `break` Set to true to enabled breaking. When a trigger is broken, the last returned value
* will be returned. If used in combination with `collectReturn` the collected results will be returned.
* Defaults to `false`.
*
* - `collectReturn` Set to true to collect the return of each object into an array.
* This array of return values will be returned from the trigger() call. Defaults to `false`.
*
* - `modParams` Allows each object the callback gets called on to modify the parameters to the next object.
* Setting modParams to an integer value will allow you to modify the parameter with that index.
* Any non-null value will modify the parameter index indicated.
* Defaults to false.
*
*
* @param string $callback|CakeEvent Method to fire on all the objects. Its assumed all the objects implement
* the method you are calling. If an instance of CakeEvent is provided, then then Event name will parsed to
* get the callback name. This is done by getting the last word after any dot in the event name
* (eg. `Model.afterSave` event will trigger the `afterSave` callback)
* @param array $params Array of parameters for the triggered callback.
* @param array $options Array of options.
* @return mixed Either the last result or all results if collectReturn is on.
* @throws CakeException when modParams is used with an index that does not exist.
*/
public function trigger($callback, $params = array(), $options = array()) {
if ($callback instanceof CakeEvent) {
$callback->omitSubject = true;
}
return parent::trigger($callback, $params, $options);
}
}