<?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(); } }