merged branch drak/genericevent (PR #3784)

Commits
-------

70a6de9 [EventDispatcher] Remove data property
4ff92b9 [EventDispatcher] Added generic event class.

Discussion
----------

[EventDispatcher] Added generic event class.

Bug fix: no
Feature addition: yes
Backwards compatibility break: no
Symfony2 tests pass: yes
Fixes the following tickets: -
Todo: -

Provides a ready to go all purpose event object.

---------------------------------------------------------------------------

by Koc at 2012-04-04T17:53:41Z

What use case of this?

---------------------------------------------------------------------------

by drak at 2012-04-04T17:57:46Z

It generically fits observer pattern use for those who do not want to make a specific event class for each and every little thing.  This is akin to EventArgs + a subject.

---------------------------------------------------------------------------

by fabpot at 2012-04-20T07:55:05Z

This is basically what we had in symfony 1.x.

Some comments:

 * I would remove the `data` as it makes things more complex and more difficult to understand (as arguments is an array, you can put your data there too);
 * I would use the standard `set`, `get`, `all`, ... methods for the `arguments` related methods

---------------------------------------------------------------------------

by drak at 2012-04-20T08:11:31Z

OK, I'll rework the class.  Thank you for your consideration.

---------------------------------------------------------------------------

by drak at 2012-04-20T08:56:53Z

@fabpot - I did some work on the class, but it seemed strange to not use get/setArgument because there is another property, the subject. This is mentioned in the conventions guide:

```
For many relations where the convention does not apply, the following methods must be used instead (where XXX is the name of the related thing):
```

If you still want me to change it, let me know.

src/Symfony/Component/EventDispatcher/GenericEvent.php

@@ -0,0 +1,180 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\EventDispatcher;
+
+/**
+ * Event encapsulation class.
+ *
+ * Encapsulates events thus decoupling the observer from the subject they encapsulate.
+ *
+ * @author Drak <drak@zikula.org>
+ */
+class GenericEvent extends Event implements \ArrayAccess
+{
+    /**
+     * Observer pattern subject.
+     *
+     * @var mixed usually object or callable
+     */
+    protected $subject;
+
+    /**
+     * Array of arguments.
+     *
+     * @var array
+     */
+    protected $arguments;
+
+    /**
+     * Encapsulate an event with $subject, $args, and $data.
+     *
+     * @param mixed  $subject   The subject of the event, usually an object.
+     * @param array  $arguments Arguments to store in the event.
+     */
+    public function __construct($subject = null, array $arguments = array())
+    {
+        $this->subject = $subject;
+        $this->arguments = $arguments;
+    }
+
+    /**
+     * Getter for subject property.
+     *
+     * @return mixed $subject The observer subject.
+     */
+    public function getSubject()
+    {
+        return $this->subject;
+    }
+
+    /**
+     * Get argument by key.
+     *
+     * @param string $key Key.
+     *
+     * @throws \InvalidArgumentException If key is not found.
+     *
+     * @return mixed Contents of array key.
+     */
+    public function getArgument($key)
+    {
+        if ($this->hasArgument($key)) {
+            return $this->arguments[$key];
+        }
+
+        throw new \InvalidArgumentException(sprintf('%s not found in %s', $key, $this->getName()));
+    }
+
+    /**
+     * Add argument to event.
+     *
+     * @param string $key   Argument name.
+     * @param mixed  $value Value.
+     *
+     * @return GenericEvent
+     */
+    public function setArgument($key, $value)
+    {
+        $this->arguments[$key] = $value;
+
+        return $this;
+    }
+
+    /**
+     * Getter for all arguments.
+     *
+     * @return array
+     */
+    public function getArguments()
+    {
+        return $this->arguments;
+    }
+
+    /**
+     * Set args property.
+     *
+     * @param array $args Arguments.
+     *
+     * @return GenericEvent
+     */
+    public function setArguments(array $args = array())
+    {
+        $this->arguments = $args;
+
+        return $this;
+    }
+
+    /**
+     * Has argument.
+     *
+     * @param string $key Key of arguments array.
+     *
+     * @return boolean
+     */
+    public function hasArgument($key)
+    {
+        return array_key_exists($key, $this->arguments);
+    }
+
+    /**
+     * ArrayAccess for argument getter.
+     *
+     * @param string $key Array key.
+     *
+     * @throws \InvalidArgumentException If key does not exist in $this->args.
+     *
+     * @return mixed
+     */
+    public function offsetGet($key)
+    {
+        return $this->getArgument($key);
+    }
+
+    /**
+     * ArrayAccess for argument setter.
+     *
+     * @param string $key   Array key to set.
+     * @param mixed  $value Value.
+     *
+     * @return void
+     */
+    public function offsetSet($key, $value)
+    {
+        $this->setArgument($key, $value);
+    }
+
+    /**
+     * ArrayAccess for unset argument.
+     *
+     * @param string $key Array key.
+     *
+     * @return void
+     */
+    public function offsetUnset($key)
+    {
+        if ($this->hasArgument($key)) {
+            unset($this->arguments[$key]);
+        }
+    }
+
+    /**
+     * ArrayAccess has argument.
+     *
+     * @param string $key Array key.
+     *
+     * @return boolean
+     */
+    public function offsetExists($key)
+    {
+        return $this->hasArgument($key);
+    }
+}

src/Symfony/Component/EventDispatcher/Tests/GenericEventTest.php

@@ -0,0 +1,131 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\EventDispatcher\Tests;
+
+use Symfony\Component\EventDispatcher\GenericEvent;
+
+/**
+ * Test class for Event.
+ */
+class GenericEventTest extends \PHPUnit_Framework_TestCase
+{
+
+    /**
+     * @var GenericEvent
+     */
+    private $event;
+
+    private $subject;
+
+    /**
+     * Prepares the environment before running a test.
+     */
+    protected function setUp()
+    {
+        parent::setUp();
+
+        $this->subject = new \StdClass();
+        $this->event = new GenericEvent($this->subject, array('name' => 'Event'), 'foo');
+    }
+
+    /**
+     * Cleans up the environment after running a test.
+     */
+    protected function tearDown()
+    {
+        $this->subject = null;
+        $this->event = null;
+
+        parent::tearDown();
+    }
+
+    public function test__construct()
+    {
+        $this->assertEquals($this->event, new GenericEvent($this->subject, array('name' => 'Event')));
+    }
+
+    /**
+     * Tests Event->getArgs()
+     */
+    public function testGetArguments()
+    {
+        // test getting all
+        $this->assertSame(array('name' => 'Event'), $this->event->getArguments());
+    }
+
+    public function testSetArguments()
+    {
+        $result = $this->event->setArguments(array('foo' => 'bar'));
+        $this->assertAttributeSame(array('foo' => 'bar'), 'arguments', $this->event);
+        $this->assertSame($this->event, $result);
+    }
+
+    public function testSetArgument()
+    {
+        $result = $this->event->setArgument('foo2', 'bar2');
+        $this->assertAttributeSame(array('name' => 'Event', 'foo2' => 'bar2'), 'arguments', $this->event);
+        $this->assertEquals($this->event, $result);
+    }
+
+    public function testGetArgument()
+    {
+        // test getting key
+        $this->assertEquals('Event', $this->event->getArgument('name'));
+    }
+
+    /**
+     * @expectedException \InvalidArgumentException
+     */
+    public function testGetArgException()
+    {
+        $this->event->getArgument('nameNotExist');
+    }
+
+    public function testOffsetGet()
+    {
+        // test getting key
+        $this->assertEquals('Event', $this->event['name']);
+
+        // test getting invalid arg
+        $this->setExpectedException('InvalidArgumentException');
+        $this->assertFalse($this->event['nameNotExist']);
+    }
+
+    public function testOffsetSet()
+    {
+        $this->event['foo2'] = 'bar2';
+        $this->assertAttributeSame(array('name' => 'Event', 'foo2' => 'bar2'), 'arguments', $this->event);
+    }
+
+    public function testOffsetUnset()
+    {
+        unset($this->event['name']);
+        $this->assertAttributeSame(array(), 'arguments', $this->event);
+    }
+
+    public function testOffsetIsset()
+    {
+        $this->assertTrue(isset($this->event['name']));
+        $this->assertFalse(isset($this->event['nameNotExist']));
+    }
+
+    public function testHasArgument()
+    {
+        $this->assertTrue($this->event->hasArgument('name'));
+        $this->assertFalse($this->event->hasArgument('nameNotExist'));
+    }
+
+    public function testGetSubject()
+    {
+        $this->assertSame($this->subject, $this->event->getSubject());
+    }
+}