Merge pull request #12 from zf-fr/add-events

Add events

CHANGELOG.md

@@ -2,7 +2,9 @@
 
 * [BC] Remove Google Bot, Yahoo and BingBot from the crawler's list, because those search engines
 support _escaped_fragment_ and want to ensure people aren't penalized for cloaking
-* The priority the listener is registered has been lowered from 10000 to 1000.
+* Prerender listener now triggers two events: "prerender.pre" and "prerender.post". This allows you to
+cache the response and return it without hitting the Prerender service
+* The priority the listener is registered has been lowered from 10000 to 1000
 
 # 1.1.2
 

README.md

@@ -130,6 +130,62 @@ return array(
 > Note: remember to specify URL here and not ZF2 route names. This occur because ZfrPrerender registers a listener
 that happen very early in the MVC process, before the routing is actually done.
 
+### Events
+
+`ZfrPrerender\Mvc\PrerenderListener` triggers two events:
+
+1. `ZfrPrerender\Mvc\PrerenderListener::EVENT_PRERENDER_PRE`: this event is triggered before actually making the
+request to Prerender service. If you return a `Zend\Http\Response` object from the listener attached to this event,
+it will immediately return this response, hence avoiding a new request to the Prerender service.
+2. `ZfrPrerender\Mvc\PrerenderListener::EVENT_PRERENDER_POST`: this event is triggered once the response from the
+Prerender service is made. This allows you to cache it (for instance in Memcached).
+
+Listeners attached to those two events receive an instance of `ZfrPrerender\Mvc\PrerenderEvent`. Here is an example
+that shows you how to register listeners using the shared event manager. In your `Module.php` class:
+
+```php
+public function onBootstrap(MvcEvent $event)
+{
+    $eventManager  = $event->getTarget()->getEventManager();
+    $sharedManager = $eventManager->getSharedManager();
+
+    $sharedManager->attach(
+        'ZfrPrerender\Mvc\PrerenderListener',
+        PrerenderListener::EVENT_PRERENDER_PRE,
+        array($this, 'prerenderPre')
+    );
+
+    $sharedManager->attach(
+        'ZfrPrerender\Mvc\PrerenderListener',
+        PrerenderListener::EVENT_PRERENDER_POST,
+        array($this, 'prerenderPost')
+    );
+}
+
+public function prerenderPre(PrerenderEvent $event)
+{
+    $request = $event->getRequest();
+
+    // Check from your cache if you have already the content
+    // $content = ...
+
+    $response = new Response();
+    $response->setStatusCode(200);
+    $response->setContent($content);
+
+    return $response;
+}
+
+public function prerenderPost(PrerenderEvent $event)
+{
+    // This is the response we get from the Prerender service
+    $response = $event->getResponse();
+
+    // You could get the body and put it in cache
+    // ...
+}
+```
+
 ### Testing
 
 If you want to make sure your pages are rendering correctly:

src/ZfrPrerender/Mvc/PrerenderEvent.php

@@ -0,0 +1,78 @@
+<?php
+/*
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the MIT license.
+ */
+
+namespace ZfrPrerender\Mvc;
+
+use Zend\EventManager\Event;
+use Zend\Http\Request as HttpRequest;
+use Zend\Http\Response as HttpResponse;
+
+/**
+ * Event that is thrown before and after a Prerender.io request
+ *
+ * @author Michaël Gallego
+ * @licence MIT
+ */
+class PrerenderEvent extends Event
+{
+    /**
+     * Event constants
+     */
+    const EVENT_PRERENDER_PRE  = 'prerender.pre';
+    const EVENT_PRERENDER_POST = 'prerender.post';
+
+    /**
+     * @var HttpRequest
+     */
+    protected $request;
+
+    /**
+     * @var HttpResponse|null
+     */
+    protected $response;
+
+    /**
+     * @param HttpRequest  $request
+     * @param HttpResponse $response
+     */
+    public function __construct(HttpRequest $request, HttpResponse $response = null)
+    {
+        $this->request  = $request;
+        $this->response = $response;
+    }
+
+    /**
+     * Get the request
+     *
+     * @return HttpRequest
+     */
+    public function getRequest()
+    {
+        return $this->request;
+    }
+
+    /**
+     * Get the response
+     *
+     * @return HttpResponse|null
+     */
+    public function getResponse()
+    {
+        return $this->response;
+    }
+}

src/ZfrPrerender/Mvc/PrerenderListener.php

@@ -19,9 +19,12 @@
 namespace ZfrPrerender\Mvc;
 
 use Zend\EventManager\AbstractListenerAggregate;
+use Zend\EventManager\EventManager;
+use Zend\EventManager\EventManagerAwareInterface;
 use Zend\EventManager\EventManagerInterface;
 use Zend\Http\Client as HttpClient;
 use Zend\Http\Request as HttpRequest;
+use Zend\Http\Response as HttpResponse;
 use Zend\Mvc\MvcEvent;
 use Zend\Stdlib\RequestInterface;
 use Zend\Stdlib\ResponseInterface;
@@ -35,7 +38,7 @@
  * @author Michaël Gallego
  * @licence MIT
  */
-class PrerenderListener extends AbstractListenerAggregate
+class PrerenderListener extends AbstractListenerAggregate implements EventManagerAwareInterface
 {
     /**
      * @var ModuleOptions
@@ -47,6 +50,11 @@ class PrerenderListener extends AbstractListenerAggregate
      */
     protected $httpClient;
 
+    /**
+     * @var EventManagerInterface
+     */
+    protected $eventManager;
+
     /**
      * @param ModuleOptions $options
      */
@@ -89,7 +97,7 @@ public function getHttpClient()
     }
 
     /**
-     * Prerender the page
+     * Pre-render the page
      *
      * @param  MvcEvent $event
      * @return void|ResponseInterface
@@ -103,14 +111,29 @@ public function prerenderPage(MvcEvent $event)
         }
 
         $event->stopPropagation(true);
+        $eventManager = $this->getEventManager();
+
+        // Trigger a pre-event (for creating a response from cache, for instance)
+        $responses = $eventManager->trigger(PrerenderEvent::EVENT_PRERENDER_PRE, new PrerenderEvent($request));
+
+        if ($responses->last() instanceof HttpResponse) {
+            return $responses->last();
+        }
 
+        // Make the actual request to Prerender service
         $client = $this->getHttpClient();
         $uri    = rtrim($this->moduleOptions->getPrerenderUrl(), '/') . '/' . $request->getUriString();
 
         $client->setUri($uri)
                ->setMethod(HttpRequest::METHOD_GET);
 
-        return $client->send();
+        $response = $client->send();
+
+        // Trigger a post-event (for putting in cache the response, for instance)
+        $prerenderEvent = new PrerenderEvent($request, $response);
+        $eventManager->trigger(PrerenderEvent::EVENT_PRERENDER_POST, $prerenderEvent);
+
+        return $prerenderEvent->getResponse();
     }
 
     /**
@@ -226,4 +249,25 @@ protected function isBlacklisted($uri, $referer, array $blacklistUrls)
 
         return false;
     }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function setEventManager(EventManagerInterface $eventManager)
+    {
+        $eventManager->setIdentifiers(array(__CLASS__, get_class($this)));
+        $this->eventManager = $eventManager;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getEventManager()
+    {
+        if (null === $this->eventManager) {
+            $this->setEventManager(new EventManager());
+        }
+
+        return $this->eventManager;
+    }
 }

tests/ZfrPrerenderTest/Mvc/PrerenderEventTest.php

@@ -0,0 +1,42 @@
+<?php
+/*
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This software consists of voluntary contributions made by many individuals
+ * and is licensed under the MIT license.
+ */
+
+namespace ZfrPrerenderTest\Mvc;
+
+use PHPUnit_Framework_TestCase as TestCase;
+use ZfrPrerender\Mvc\PrerenderEvent;
+
+/**
+ * @author Michaël Gallego <[email protected]>
+ *
+ * @covers \ZfrPrerender\Mvc\PrerenderEvent
+ * @group Coverage
+ */
+class PrerenderEventTest extends TestCase
+{
+    public function testGetters()
+    {
+        $request  = $this->getMock('Zend\Http\Request');
+        $response = $this->getMock('Zend\Http\Response');
+
+        $event = new PrerenderEvent($request, $response);
+
+        $this->assertSame($request, $event->getRequest());
+        $this->assertSame($response, $event->getResponse());
+    }
+}

tests/ZfrPrerenderTest/Mvc/PrerenderListenerTest.php

@@ -20,8 +20,10 @@
 
 use PHPUnit_Framework_TestCase as TestCase;
 use Zend\EventManager\EventManager;
+use Zend\EventManager\ResponseCollection;
 use Zend\Http\Request as HttpRequest;
 use Zend\Mvc\MvcEvent;
+use ZfrPrerender\Mvc\PrerenderEvent;
 use ZfrPrerender\Mvc\PrerenderListener;
 use ZfrPrerender\Options\ModuleOptions;
 use ZfrPrerenderTest\Util\ServiceManagerFactory;
@@ -289,11 +291,49 @@ public function testCanPerformGetRequest()
 
         $clientMock->expects($this->once())
                    ->method('send')
-                   ->will($this->returnValue($this->getMock('Zend\Stdlib\ResponseInterface')));
+                   ->will($this->returnValue($this->getMock('Zend\Http\Response')));
 
         $listener->setHttpClient($clientMock);
 
         $response = $listener->prerenderPage($mvcEvent);
         $this->assertInstanceOf('Zend\Stdlib\ResponseInterface', $response);
     }
+
+    public function testSetCorrectIdentifiers()
+    {
+        $listener = new PrerenderListener(new ModuleOptions());
+        $listener->setEventManager(new EventManager());
+
+        $eventManager = $listener->getEventManager();
+
+        $this->assertEquals(array('ZfrPrerender\Mvc\PrerenderListener'), $eventManager->getIdentifiers());
+    }
+
+    public function testTriggerEventsAndStopIfResponseIsReturned()
+    {
+        $mvcEvent   = new MvcEvent();
+        $request    = new HttpRequest();
+
+        $request->setUri('http://www.example.com');
+        $request->getHeaders()->addHeaderLine('User-Agent', 'Baiduspider+(+http://www.baidu.com/search/spider.htm)');
+        $mvcEvent->setRequest($request);
+
+        $eventManager = $this->getMock('Zend\EventManager\EventManagerInterface');
+
+        $moduleOptions = ServiceManagerFactory::getServiceManager()->get('ZfrPrerender\Options\ModuleOptions');
+
+        $listener = new PrerenderListener($moduleOptions);
+        $listener->setEventManager($eventManager);
+
+        $response           = $this->getMock('Zend\Http\Response');
+        $responseCollection = new ResponseCollection();
+        $responseCollection->push($response);
+
+        $eventManager->expects($this->once())
+                     ->method('trigger')
+                     ->with(PrerenderEvent::EVENT_PRERENDER_PRE)
+                     ->will($this->returnValue($responseCollection));
+
+        $this->assertSame($response, $listener->prerenderPage($mvcEvent));
+    }
 }