Yii 2.0有关页面缓存方法讲解

<?php 


namespace common\lib;

use Yii;
use yii\caching\Cache;
use yii\di\Instance;
use yii\web\Response;
use yii\filters\PageCache as PCache;


/**
* 重写页面缓存，增加varByParam参数一列
*/
class PageCache extends PCache
{
 /**
 * 参数设置，默认无参数
 * 用法：'varByParam' => Yii::$app->request->get('id')
 * @var string
 */
 public $varByParam = '';

 public function beforeAction($action)
 {
 if (!$this->enabled) {
  return true;
 }

 $this->cache = Instance::ensure($this->cache, Cache::className());

 if (is_array($this->dependency)) {
  $this->dependency = Yii::createObject($this->dependency);
 }

 $properties = [];
 foreach (['cache', 'duration', 'dependency', 'variations'] as $name) {
  $properties[$name] = $this->$name;
 }
 $id = $this->varyByRoute ? $action->getUniqueId().$this->varByParam : __CLASS__;
 $response = Yii::$app->getResponse();
 ob_start();
 ob_implicit_flush(false);
 if ($this->view->beginCache($id, $properties)) {
  $response->on(Response::EVENT_AFTER_SEND, [$this, 'cacheResponse']);
  return true;
 } else {
  $data = $this->cache->get($this->calculateCacheKey());
  if (is_array($data)) {
  $this->restoreResponse($response, $data);
  }
  $response->content = ob_get_clean();
  return false;
 }
 }
}
 ?>

[
'class' => 'common\lib\PageCache',
  'only' => ['view'],
  'duration' => 0, //永不过期
  'varByParam' => Yii::$app->request->get('id'),
],