<?php
/**
* Joomla! Content Management System
*
* @copyright Copyright (C) 2005 - 2019 Open Source Matters, Inc. All rights reserved.
* @license GNU General Public License version 2 or later; see LICENSE.txt
*/
namespace Joomla\CMS\Cache\Controller;
defined('JPATH_PLATFORM') or die;
use Joomla\CMS\Cache\Cache;
use Joomla\CMS\Cache\CacheController;
/**
* Joomla! Cache view type object
*
* @since 1.7.0
*/
class ViewController extends CacheController
{
/**
* Get the cached view data
*
* @param object $view The view object to cache output for
* @param string $method The method name of the view method to cache output for
* @param mixed $id The cache data ID
* @param boolean $wrkarounds True to enable workarounds.
*
* @return boolean True if the cache is hit (false else)
*
* @since 1.7.0
*/
public function get($view, $method = 'display', $id = false, $wrkarounds = true)
{
// If an id is not given generate it from the request
if (!$id)
{
$id = $this->_makeId($view, $method);
}
$data = $this->cache->get($id);
$locktest = (object) array('locked' => null, 'locklooped' => null);
if ($data === false)
{
$locktest = $this->cache->lock($id);
/*
* If the loop is completed and returned true it means the lock has been set.
* If looped is true try to get the cached data again; it could exist now.
*/
if ($locktest->locked === true && $locktest->locklooped === true)
{
$data = $this->cache->get($id);
}
// False means that locking is either turned off or maxtime has been exceeded. Execute the view.
}
if ($data !== false)
{
if ($locktest->locked === true)
{
$this->cache->unlock($id);
}
$data = unserialize(trim($data));
if ($wrkarounds)
{
echo Cache::getWorkarounds($data);
}
else
{
// No workarounds, so all data is stored in one piece
echo $data;
}
return true;
}
// No hit so we have to execute the view
if (!method_exists($view, $method))
{
return false;
}
if ($locktest->locked === false && $locktest->locklooped === true)
{
// We can not store data because another process is in the middle of saving
$view->$method();
return false;
}
// Capture and echo output
ob_start();
ob_implicit_flush(false);
$view->$method();
$data = ob_get_clean();
echo $data;
/*
* For a view we have a special case. We need to cache not only the output from the view, but the state
* of the document head after the view has been rendered. This will allow us to properly cache any attached
* scripts or stylesheets or links or any other modifications that the view has made to the document object
*/
if ($wrkarounds)
{
$data = Cache::setWorkarounds($data);
}
// Store the cache data
$this->cache->store(serialize($data), $id);
if ($locktest->locked === true)
{
$this->cache->unlock($id);
}
return false;
}
/**
* Generate a view cache ID.
*
* @param object $view The view object to cache output for
* @param string $method The method name to cache for the view object
*
* @return string MD5 Hash
*
* @since 1.7.0
*/
protected function _makeId($view, $method)
{
return md5(serialize(array(Cache::makeId(), get_class($view), $method)));
}
}