From a36a1624fb4deb94d9261abf7aa9bcecf7246fc1 Mon Sep 17 00:00:00 2001
From: Benjamin Eberlei <kontakt@beberlei.de>
Date: Thu, 13 Oct 2011 22:58:22 +0200
Subject: [PATCH] [DDC-1415] Add EntityEventDelegatee, allowing to restrict
 emitting events to certain entity classes only.

---
 .../ORM/Event/EntityEventDelegator.php        | 110 ++++++++++++++++++
 .../ORM/Event/EntityEventDelegateeTest.php    |  91 +++++++++++++++
 2 files changed, 201 insertions(+)
 create mode 100644 lib/Doctrine/ORM/Event/EntityEventDelegator.php
 create mode 100644 tests/Doctrine/Tests/ORM/Event/EntityEventDelegateeTest.php

diff --git a/lib/Doctrine/ORM/Event/EntityEventDelegator.php b/lib/Doctrine/ORM/Event/EntityEventDelegator.php
new file mode 100644
index 000000000..d7c46e68e
--- /dev/null
+++ b/lib/Doctrine/ORM/Event/EntityEventDelegator.php
@@ -0,0 +1,110 @@
+<?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 LGPL. For more information, see
+ * <http://www.doctrine-project.org>.
+*/
+
+namespace Doctrine\ORM\Event;
+
+use \Doctrine\Common\EventSubscriber;
+use \LogicException;
+
+/**
+ * Delegate events only for certain entities they are registered for.
+ *
+ * @author Benjamin Eberlei <kontakt@beberlei.de>
+ * @since 2.2
+ */
+class EntityEventDelegator implements EventSubscriber
+{
+    /**
+     * Keeps track of all the event listeners.
+     *
+     * @var array
+     */
+    private $listeners = array();
+
+    /**
+     * If frozen no new event listeners can be added.
+     *
+     * @var bool
+     */
+    private $frozen = false;
+
+    /**
+     * Adds an event listener that listens on the specified events.
+     *
+     * @param string|array $events The event(s) to listen on.
+     * @param string|array $entities The entities to trigger this listener for
+     * @param object $listener The listener object.
+     */
+    public function addEventListener($events, $entities, $listener)
+    {
+        if ($this->frozen) {
+            throw new LogicException("Cannot add event listeners after EntityEventDelegator::getSubscribedEvents() " .
+                "is called once. This happens when you register the delegator with the event manager.");
+        }
+
+        // Picks the hash code related to that listener
+        $hash = spl_object_hash($listener);
+
+        foreach ((array) $events as $event) {
+            // Overrides listener if a previous one was associated already
+            // Prevents duplicate listeners on same event (same instance only)
+            $this->listeners[$event][$hash] = array('listener' => $listener, 'entities' => array_flip((array)$entities));
+        }
+    }
+
+    /**
+     * Adds an EventSubscriber. The subscriber is asked for all the events he is
+     * interested in and added as a listener for these events.
+     *
+     * @param Doctrine\Common\EventSubscriber $subscriber The subscriber.
+     */
+    public function addEventSubscriber(EventSubscriber $subscriber, $entities)
+    {
+        $this->addEventListener($subscriber->getSubscribedEvents(), $entities, $subscriber);
+    }
+
+    /**
+     * Returns an array of events this subscriber wants to listen to.
+     *
+     * @return array
+     */
+    public function getSubscribedEvents()
+    {
+        $this->frozen = true;
+        return array_keys($this->listeners);
+    }
+
+    /**
+     * Delegate the event to an appropriate listener
+     *
+     * @param $eventName
+     * @param $event
+     * @return void
+     */
+    public function __call($eventName, $args)
+    {
+        $event = $args[0];
+        foreach ($this->listeners[$eventName] AS $listenerData) {
+            $class = get_class($event->getEntity());
+            if (isset($listenerData['entities'][$class])) {
+                $listenerData['listener']->$eventName($event);
+            }
+        }
+    }
+}
diff --git a/tests/Doctrine/Tests/ORM/Event/EntityEventDelegateeTest.php b/tests/Doctrine/Tests/ORM/Event/EntityEventDelegateeTest.php
new file mode 100644
index 000000000..5c4db0101
--- /dev/null
+++ b/tests/Doctrine/Tests/ORM/Event/EntityEventDelegateeTest.php
@@ -0,0 +1,91 @@
+<?php
+
+namespace Doctrine\Tests\ORM\Event;
+
+use Doctrine\ORM\Mapping\ClassMetadata;
+
+/**
+ * @group DDC-1415
+ */
+class EntityEventDelegatorTest extends \Doctrine\Tests\OrmTestCase
+{
+    /**
+     * @var \Doctrine\ORM\Event\EntityEventDelegator
+     */
+    private $delegator;
+
+    public function setUp()
+    {
+        $this->delegator = new \Doctrine\ORM\Event\EntityEventDelegator();
+    }
+
+    public function testGetSubscribedEventsWhenEmpty()
+    {
+        $this->assertEquals(array(), $this->delegator->getSubscribedEvents());
+    }
+
+    public function testAddListener()
+    {
+        $this->delegator->addEventListener('postLoad', 'stdClass', new DelegateeEventListener());
+        $this->assertEquals(array('postLoad'), $this->delegator->getSubscribedEvents());
+    }
+
+    public function testAddSubscriber()
+    {
+        $this->delegator->addEventSubscriber(new DelegateeEventListener(), 'stdClass');
+        $this->assertEquals(array('postLoad'), $this->delegator->getSubscribedEvents());
+    }
+
+    public function testAddListenerAfterFrozenThrowsException()
+    {
+        $this->delegator->getSubscribedEvents(); // freezes
+
+        $this->setExpectedException("LogicException", "Cannot add event listeners aft");
+        $this->delegator->addEventListener('postLoad', 'stdClass', new DelegateeEventListener());
+    }
+
+    public function testDelegateEvent()
+    {
+        $delegatee = new DelegateeEventListener();
+        $this->delegator->addEventListener('postLoad', 'stdClass', $delegatee);
+
+        $event = new \Doctrine\ORM\Event\LifecycleEventArgs(new \stdClass(), $this->_getTestEntityManager());
+        $this->delegator->postLoad($event);
+        $this->delegator->postLoad($event);
+
+        $this->assertEquals(2, $delegatee->postLoad);
+    }
+
+    public function testDelegatePickEntity()
+    {
+        $delegatee = new DelegateeEventListener();
+        $this->delegator->addEventListener('postLoad', 'stdClass', $delegatee);
+
+        $event1 = new \Doctrine\ORM\Event\LifecycleEventArgs(new \stdClass(), $this->_getTestEntityManager());
+        $event2 = new \Doctrine\ORM\Event\LifecycleEventArgs(new \Doctrine\Tests\Models\CMS\CmsUser(), $this->_getTestEntityManager());
+        $this->delegator->postLoad($event1);
+        $this->delegator->postLoad($event2);
+
+        $this->assertEquals(1, $delegatee->postLoad);
+    }
+}
+
+class DelegateeEventListener implements \Doctrine\Common\EventSubscriber
+{
+    public $postLoad = 0;
+
+    public function postLoad($args)
+    {
+        $this->postLoad++;
+    }
+
+    /**
+     * Returns an array of events this subscriber wants to listen to.
+     *
+     * @return array
+     */
+    function getSubscribedEvents()
+    {
+        return array('postLoad');
+    }
+}
\ No newline at end of file