我们可以为Phalcon的View添加事件监听，View一共有5个事件：
| Event Name | Triggered | Can stop operation ? |
|---|---|---|
| beforeRender | Triggered before starting the render process | Yes |
| beforeRenderView | Triggered before rendering an existing view | Yes |
| afterRenderView | Triggered after rendering an existing view | No |
| afterRender | Triggered after completing the render process | No |
| notFoundView | Triggered when a view was not found | No |
在di注入是view时添加事件：
<?php
use Phalcon\Events\Event;
use Phalcon\Events\Manager as EventsManager;
use Phalcon\Mvc\View;
$di->set(
'view',
function () {
// Create an events manager
$eventsManager = new EventsManager();
// Attach a listener for type 'view'
$eventsManager->attach(
'view',
function (Event $event, $view) {
echo $event->getType(), ' - ', $view->getActiveRenderPath(), PHP_EOL;
}
);
$view = new View();
$view->setViewsDir('../app/views/');
// Bind the eventsManager to the view component
$view->setEventsManager($eventsManager);
return $view;
},
true
);上面是监听了View的所有事件,如果要监听某个具体的,如监听beforeRender：
$eventsManager->attach('view:beforeRender', function(){
})现在，就可以利用afterRender事件来缓存页面，提升性能。
首先，需要向di注入一个viewCache服务：
<?php
use Phalcon\Cache\Frontend\Output as OutputFrontend;
use Phalcon\Cache\Backend\Memcache as MemcacheBackend;
// Set the views cache service
$di->set(
'viewCache',
function () {
// Cache data for one day by default
$frontCache = new OutputFrontend(
[
'lifetime' => 86400,
]
);
// Memcached connection settings
$cache = new MemcacheBackend(
$frontCache,
[
'host' => 'localhost',
'port' => '11211',
]
);
return $cache;
}
);这里的cache也可以换成Redis等你在使用的。lifetime为默认缓存时间，当调用该服务时，可以另外给出lifetime的值。键为key。Phalcon会默认使用MD5加密当前的Controller/view。
定义afterRender事件触发时要做的事情:
class ViewPlugin extends \Phalcon\Mvc\User\Plugin {
public function afterRender(\Phalcon\Events\Event $event, $view){
$request = \Phalcon\Di::getDefault()->get('request');
$key = md5($request->getURI());
if (!$view->getCache()->exists($key)) {
$view->getCache()->save($key, $view->getContent(), DEFAULT_VIEW_EXPIRE_TIME);
}
}
}这样当访问一个新页面后就会缓存下来。接下来就是第二步，再次访问该页面时，直接向浏览器输出缓存内容，可以定义在父类里：
$this->view_cache_key = md5($this->request->getURI());
if ($this->view->getCache()->exists($this->view_cache_key)) {
echo $this->view->getCache()->get($this->view_cache_key);
exit;
}这就是利用View的事件缓存页面，当然也可以用于其他场景，如生成静态HTML页面
参考文档: