* @since 2.0
*/
class FragmentCache extends Widget
{
/**
* Prefix to the keys for storing cached data
*/
const CACHE_KEY_PREFIX = 'Yii.COutputCache.';
/**
* @var string the ID of the cache application component. Defaults to 'cache' (the primary cache application component.)
*/
public $cacheID = 'cache';
/**
* @var integer number of seconds that the data can remain in cache. Defaults to 60 seconds.
* If it is 0, existing cached content would be removed from the cache.
* If it is a negative value, the cache will be disabled (any existing cached content will
* remain in the cache.)
*
* Note, if cache dependency changes or cache space is limited,
* the data may be purged out of cache earlier.
*/
public $duration = 60;
/**
* @var mixed the dependency that the cached content depends on.
* This can be either an object implementing {@link ICacheDependency} interface or an array
* specifying the configuration of the dependency object. For example,
*
* array(
* 'class'=>'CDbCacheDependency',
* 'sql'=>'SELECT MAX(lastModified) FROM Post',
* )
*
* would make the output cache depends on the last modified time of all posts.
* If any post has its modification time changed, the cached content would be invalidated.
*/
public $dependency;
/**
* @var boolean whether the content being cached should be differentiated according to route.
* A route consists of the requested controller ID and action ID.
* Defaults to true.
*/
public $varyByRoute = true;
/**
* @var boolean whether the content being cached should be differentiated according to user's language.
* A language is retrieved via Yii::app()->language.
* Defaults to false.
* @since 1.1.14
*/
public $varyByLanguage = false;
/**
* @var array list of GET parameters that should participate in cache key calculation.
* By setting this property, the output cache will use different cached data
* for each different set of GET parameter values.
*/
public $varyByParam;
/**
* @var string a PHP expression whose result is used in the cache key calculation.
* By setting this property, the output cache will use different cached data
* for each different expression result.
* The expression can also be a valid PHP callback,
* including class method name (array(ClassName/Object, MethodName)),
* or anonymous function (PHP 5.3.0+). The function/method signature should be as follows:
*
* function foo($cache) { ... }
*
* where $cache refers to the output cache component.
*/
public $varyByExpression;
/**
* @var array list of request types (e.g. GET, POST) for which the cache should be enabled only.
* Defaults to null, meaning all request types.
*/
public $requestTypes;
private $_key;
private $_cache;
private $_contentCached;
private $_content;
private $_actions;
/**
* Marks the start of content to be cached.
* Content displayed after this method call and before {@link endCache()}
* will be captured and saved in cache.
* This method does nothing if valid content is already found in cache.
*/
public function init()
{
if ($this->getIsContentCached()) {
$this->replayActions();
} elseif ($this->_cache !== null) {
$this->getController()->getCachingStack()->push($this);
ob_start();
ob_implicit_flush(false);
}
}
/**
* Marks the end of content to be cached.
* Content displayed before this method call and after {@link init()}
* will be captured and saved in cache.
* This method does nothing if valid content is already found in cache.
*/
public function run()
{
if ($this->getIsContentCached()) {
if ($this->getController()->isCachingStackEmpty()) {
echo $this->getController()->processDynamicOutput($this->_content);
} else {
echo $this->_content;
}
} elseif ($this->_cache !== null) {
$this->_content = ob_get_clean();
$this->getController()->getCachingStack()->pop();
$data = array($this->_content, $this->_actions);
if (is_array($this->dependency)) {
$this->dependency = Yii::createComponent($this->dependency);
}
$this->_cache->set($this->getCacheKey(), $data, $this->duration, $this->dependency);
if ($this->getController()->isCachingStackEmpty()) {
echo $this->getController()->processDynamicOutput($this->_content);
} else {
echo $this->_content;
}
}
}
/**
* @return boolean whether the content can be found from cache
*/
public function getIsContentCached()
{
if ($this->_contentCached !== null) {
return $this->_contentCached;
} else {
return $this->_contentCached = $this->checkContentCache();
}
}
/**
* Looks for content in cache.
* @return boolean whether the content is found in cache.
*/
protected function checkContentCache()
{
if ((empty($this->requestTypes) || in_array(Yii::app()->getRequest()->getRequestType(), $this->requestTypes))
&& ($this->_cache = $this->getCache()) !== null
) {
if ($this->duration > 0 && ($data = $this->_cache->get($this->getCacheKey())) !== false) {
$this->_content = $data[0];
$this->_actions = $data[1];
return true;
}
if ($this->duration == 0) {
$this->_cache->delete($this->getCacheKey());
}
if ($this->duration <= 0) {
$this->_cache = null;
}
}
return false;
}
/**
* @return ICache the cache used for caching the content.
*/
protected function getCache()
{
return Yii::app()->getComponent($this->cacheID);
}
/**
* Caclulates the base cache key.
* The calculated key will be further variated in {@link getCacheKey}.
* Derived classes may override this method if more variations are needed.
* @return string basic cache key without variations
*/
protected function getBaseCacheKey()
{
return self::CACHE_KEY_PREFIX . $this->getId() . '.';
}
/**
* Calculates the cache key.
* The key is calculated based on {@link getBaseCacheKey} and other factors, including
* {@link varyByRoute}, {@link varyByParam}, {@link varyBySession} and {@link varyByLanguage}.
* @return string cache key
*/
protected function getCacheKey()
{
if ($this->_key !== null) {
return $this->_key;
} else {
$key = $this->getBaseCacheKey() . '.';
if ($this->varyByRoute) {
$controller = $this->getController();
$key .= $controller->getUniqueId() . '/';
if (($action = $controller->getAction()) !== null) {
$key .= $action->getId();
}
}
$key .= '.';
if ($this->varyBySession) {
$key .= Yii::app()->getSession()->getSessionID();
}
$key .= '.';
if (is_array($this->varyByParam) && isset($this->varyByParam[0])) {
$params = array();
foreach ($this->varyByParam as $name) {
if (isset($_GET[$name])) {
$params[$name] = $_GET[$name];
} else {
$params[$name] = '';
}
}
$key .= serialize($params);
}
$key .= '.';
if ($this->varyByExpression !== null) {
$key .= $this->evaluateExpression($this->varyByExpression);
}
$key .= '.';
if ($this->varyByLanguage) {
$key .= Yii::app()->language;
}
$key .= '.';
return $this->_key = $key;
}
}
/**
* Records a method call when this output cache is in effect.
* When the content is served from the output cache, the recorded
* method will be re-invoked.
* @param string $context a property name of the controller. The property should refer to an object
* whose method is being recorded. If empty it means the controller itself.
* @param string $method the method name
* @param array $params parameters passed to the method
*/
public function recordAction($context, $method, $params)
{
$this->_actions[] = array($context, $method, $params);
}
/**
* Replays the recorded method calls.
*/
protected function replayActions()
{
if (empty($this->_actions)) {
return;
}
$controller = $this->getController();
$cs = Yii::app()->getClientScript();
foreach ($this->_actions as $action) {
if ($action[0] === 'clientScript') {
$object = $cs;
} elseif ($action[0] === '') {
$object = $controller;
} else {
$object = $controller->{$action[0]};
}
if (method_exists($object, $action[1])) {
call_user_func_array(array($object, $action[1]), $action[2]);
} elseif ($action[0] === '' && function_exists($action[1])) {
call_user_func_array($action[1], $action[2]);
} else {
throw new CException(Yii::t('yii', 'Unable to replay the action "{object}.{method}". The method does not exist.',
array('object' => $action[0],
'method' => $action[1])));
}
}
}
}