Added subscriber options to HttpCache

Based on #177, ref #170

This PR adds 2 options that one can add in their `getOptions()`:

* `fos_native_subscribers`: bit options to activate/deactivate subscribers provided by FOSHttpCacheBundle
* `fos_subscribers`: Array of custom subscribers to add to the event dispatcher

> By default **all native subscribers are activated** (`HttpCache::SUBSCRIBER_ALL`).

**ALL native subscribers EXCEPT the user context one**
```php
public function getOptions()
{
    return [
        'fos_native_subscribers' => self::SUBSCRIBER_ALL | ~self::SUBSCRIBER_USER_CONTEXT
    ]
}
```

**NO native subscribers**
```php
public function getOptions()
{
    return [
        'fos_native_subscribers' => self::SUBSCRIBER_NONE
    ]
}
```

**ONLY user context subscribers**
```php
public function getOptions()
{
    return [
        'fos_native_subscribers' => self::SUBSCRIBER_USER_CONTEXT
    ]
}
```

**User context subscriber AND Foo subscriber**
```php
public function getOptions()
{
    return [
        'fos_native_subscribers' => self::SUBSCRIBER_USER_CONTEXT | self::SUBSCRIBER_FOO
    ]
}
```

**NO native subscribers + custom subscriber **
```php
public function getOptions()
{
    return [
        'fos_native_subscribers' => self::SUBSCRIBER_NONE,
        'fos_subscribers' => [new MySubscriber()]
    ]
}
```

**ALL native subscribers (default) + custom subscriber **
```php
public function getOptions()
{
    return [
        'fos_subscribers' => [new MySubscriber()]
    ]
}
```

Author: lolautruche

HttpCache.php

@@ -11,6 +11,7 @@
 
 namespace FOS\HttpCacheBundle;
 
+use FOS\HttpCacheBundle\SymfonyCache\UserContextSubscriber;
 use FOS\HttpCacheBundle\SymfonyCache\CacheEvent;
 use FOS\HttpCacheBundle\SymfonyCache\Events;
 use Symfony\Bundle\FrameworkBundle\HttpCache\HttpCache as BaseHttpCache;
@@ -22,18 +23,40 @@
 
 /**
  * Base class for enhanced Symfony reverse proxy.
+ * It can register event subscribers that may alter the request received.
  *
  * @author Jérôme Vieilledent <[email protected]> (courtesy of eZ Systems AS)
  *
  * {@inheritdoc}
  */
 abstract class HttpCache extends BaseHttpCache
 {
+    /**
+     * Options to indicate which native subscriber(s) to use.
+     * They are to be used in the hash returned by getOptions(), with "fos_native_subscribers" key.
+     *
+     * These are bit options, use bitwise operators to combine them:
+     * self::SUBSCRIBER_ALL | ~SUBSCRIBER_USER_CONTEXT => All but user context.
+     * self::SUBSCRIBER_USER_CONTEXT | self::SUBSCRIBER_FOO => User context AND foo subscribers ONLY.
+     */
+    const SUBSCRIBER_ALL = -1; // Equals to ~0
+    const SUBSCRIBER_NONE = 0;
+    const SUBSCRIBER_USER_CONTEXT = 1;
+
     /**
      * @var EventDispatcherInterface
      */
     private $eventDispatcher;
 
+    public function __construct(HttpKernelInterface $kernel, $cacheDir = null)
+    {
+        parent::__construct($kernel, $cacheDir);
+
+        foreach ($this->getSubscribers() as $subscriber) {
+            $this->addSubscriber($subscriber);
+        }
+    }
+
     /**
      * Set event dispatcher
      *
@@ -74,6 +97,23 @@ public function addSubscriber(EventSubscriberInterface $subscriber)
         return $this;
     }
 
+    /**
+     * Returns subscribers to be added to the event dispatcher, in respect to options defined in `getOptions()`.
+     *
+     * @return EventSubscriberInterface[]
+     */
+    public function getSubscribers()
+    {
+        $options = $this->getOptions();
+        $subscribers = isset($options['fos_subscribers']) ? $options['fos_subscribers'] : array();
+        $nativeSubscribersOption = isset($options['fos_native_subscribers']) ? $options['fos_native_subscribers'] : self::SUBSCRIBER_ALL;
+        if ($nativeSubscribersOption & self::SUBSCRIBER_USER_CONTEXT) {
+            $subscribers[] = new UserContextSubscriber();
+        }
+
+        return $subscribers;
+    }
+
     public function handle(Request $request, $type = HttpKernelInterface::MASTER_REQUEST, $catch = true)
     {
         if ($this->getEventDispatcher()->hasListeners(Events::PRE_HANDLE)) {

SymfonyCache/UserContextSubscriber.php

@@ -78,9 +78,7 @@ public static function getSubscribedEvents()
     /**
      * Check on the handle event.
      *
-     * @param Request $request
-     * @param $type
-     * @param $catch
+     * @param CacheEvent $event
      *
      * @return Response|null If response is returned, this response should be used.
      *                       Otherwise let the kernel handle this request.

Tests/Unit/SymfonyCache/HttpCacheTest.php

@@ -14,7 +14,7 @@
 use FOS\HttpCacheBundle\HttpCache;
 use FOS\HttpCacheBundle\SymfonyCache\CacheEvent;
 use FOS\HttpCacheBundle\SymfonyCache\Events;
-use FOS\HttpCacheBundle\SymfonyCache\UserContextHandler;
+use FOS\HttpCacheBundle\SymfonyCache\UserContextSubscriber;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\Response;
@@ -103,6 +103,63 @@ public function testAbort()
         $this->assertEquals(1, $subscriber->hits);
         $this->assertSame($response, $httpCache->handle($request, HttpKernelInterface::MASTER_REQUEST, $catch));
     }
+
+    /**
+     * @dataProvider configuredSubscribersProvider
+     */
+    public function testConfiguredSubscribers(array $options, array $expectedSubscribers)
+    {
+        $cacheKernel = $this->getHttpCachePartialMock(array('getOptions'));
+        $cacheKernel
+            ->expects($this->once())
+            ->method('getOptions')
+            ->will($this->returnValue($options));
+
+        $this->assertEquals($expectedSubscribers, $cacheKernel->getSubscribers());
+    }
+
+    public function configuredSubscribersProvider()
+    {
+        $mockSubscriber1 = $this->getMock('\Symfony\Component\EventDispatcher\EventSubscriberInterface');
+        $mockSubscriber2 = $this->getMock('\Symfony\Component\EventDispatcher\EventSubscriberInterface');
+        $mockSubscriber3 = $this->getMock('\Symfony\Component\EventDispatcher\EventSubscriberInterface');
+
+        return array(
+            array(array(), array(new UserContextSubscriber())),
+            array(
+                array(
+                    'fos_native_subscribers' => HttpCache::SUBSCRIBER_ALL,
+                ),
+                array(new UserContextSubscriber())
+            ),
+            array(
+                array(
+                    'fos_native_subscribers' => HttpCache::SUBSCRIBER_NONE,
+                ),
+                array()
+            ),
+            array(
+                array(
+                    'fos_native_subscribers' => HttpCache::SUBSCRIBER_USER_CONTEXT,
+                    'fos_subscribers' => array($mockSubscriber1)
+                ),
+                array($mockSubscriber1, new UserContextSubscriber())
+            ),
+            array(
+                array(
+                    'fos_native_subscribers' => HttpCache::SUBSCRIBER_NONE,
+                    'fos_subscribers' => array($mockSubscriber1, $mockSubscriber2)
+                ),
+                array($mockSubscriber1, $mockSubscriber2)
+            ),
+            array(
+                array(
+                    'fos_subscribers' => array($mockSubscriber1, $mockSubscriber2, $mockSubscriber3)
+                ),
+                array($mockSubscriber1, $mockSubscriber2, $mockSubscriber3, new UserContextSubscriber())
+            ),
+        );
+    }
 }
 
 class TestSubscriber implements EventSubscriberInterface