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<?php
/**
* @link http://www.yiiframework.com/
* @copyright Copyright (c) 2008 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
namespace yii\web;
use Yii;
use yii\base\ActionFilter;
use yii\base\Action;
use yii\caching\Dependency;
/**
* The PageCache provides functionality for whole page caching
*
* It is an action filter that can be added to a controller and handles the `beforeAction` event.
*
* To use PageCache, declare it in the `behaviors()` method of your controller class.
* In the following example the filter will be applied to the `list`-action and
* cache the whole page for maximum 60 seconds or until the count of entries in the post table changes.
* It also stores different versions of the page depended on the route ([[varyByRoute]] is true by default),
* the application language and user id.
*
* ~~~
* public function behaviors()
* {
* return [
* 'pageCache' => [
* 'class' => \yii\web\PageCache::className(),
* 'only' => ['list'],
* 'duration' => 60,
* 'dependecy' => [
* 'class' => 'yii\caching\DbDependency',
* 'sql' => 'SELECT COUNT(*) FROM post',
* ],
* 'variations' => [
* Yii::$app->language,
* Yii::$app->user->id
* ]
* ],
* ];
* }
* ~~~
*
* @author Qiang Xue <qiang.xue@gmail.com>
* @since 2.0
*/
class PageCache extends ActionFilter
{
/**
* @var boolean whether the content being cached should be differentiated according to the route.
* A route consists of the requested controller ID and action ID. Defaults to true.
*/
public $varyByRoute = true;
/**
* @var string the application component ID of the [[\yii\caching\Cache|cache]] object.
*/
public $cache = 'cache';
/**
* @var integer number of seconds that the data can remain valid in cache.
* Use 0 to indicate that the cached data will never expire.
*/
public $duration = 60;
/**
* @var array|Dependency the dependency that the cached content depends on.
* This can be either a [[Dependency]] object or a configuration array for creating the dependency object.
* For example,
*
* ~~~
* [
* 'class' => 'yii\caching\DbDependency',
* '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 $dependency;
/**
* @var array list of factors that would cause the variation of the content being cached.
* Each factor is a string representing a variation (e.g. the language, a GET parameter).
* The following variation setting will cause the content to be cached in different versions
* according to the current application language:
*
* ~~~
* [
* Yii::$app->language,
* ]
* ~~~
*/
public $variations;
/**
* @var boolean whether to enable the fragment cache. You may use this property to turn on and off
* the fragment cache according to specific setting (e.g. enable fragment cache only for GET requests).
*/
public $enabled = true;
/**
* @var \yii\base\View the view component to use for caching. If not set, the default application view component
* [[Application::view]] will be used.
*/
public $view;
public function init()
{
parent::init();
if ($this->view === null) {
$this->view = Yii::$app->getView();
}
}
/**
* This method is invoked right before an action is to be executed (after all possible filters.)
* You may override this method to do last-minute preparation for the action.
* @param Action $action the action to be executed.
* @return boolean whether the action should continue to be executed.
*/
public function beforeAction($action)
{
$properties = [];
foreach (['cache', 'duration', 'dependency', 'variations', 'enabled'] as $name) {
$properties[$name] = $this->$name;
}
$id = $this->varyByRoute ? $action->getUniqueId() : __CLASS__;
ob_start();
ob_implicit_flush(false);
if ($this->view->beginCache($id, $properties)) {
return true;
} else {
Yii::$app->getResponse()->content = ob_get_clean();
return false;
}
}
/**
* @inheritdoc
*/
public function afterAction($action, $result)
{
echo $result;
$this->view->endCache();
return ob_get_clean();
}
}