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https://github.com/b00gizm/eventdispatcherextra
This package provides some useful additions and tweaks to Symfony's EventDispatcher component
https://github.com/b00gizm/eventdispatcherextra
Last synced: 3 days ago
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This package provides some useful additions and tweaks to Symfony's EventDispatcher component
- Host: GitHub
- URL: https://github.com/b00gizm/eventdispatcherextra
- Owner: b00giZm
- License: mit
- Created: 2012-05-25T14:05:23.000Z (over 12 years ago)
- Default Branch: master
- Last Pushed: 2012-06-15T13:34:59.000Z (over 12 years ago)
- Last Synced: 2023-03-10T22:41:53.061Z (over 1 year ago)
- Language: PHP
- Homepage:
- Size: 109 KB
- Stars: 2
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
# EventDispatcherExtra
[](http://travis-ci.org/b00giZm/EventDispatcherExtra)
This package provides some useful additions and tweaks to Symfony's [EventDispatcher component](http://symfony.com/doc/current/components/event_dispatcher/introduction.html).
## Install
Install of the library and its dependencies via [Composer](http://getcomposer.org/).
``` bash
curl -s http://getcomposer.org/installer | php
php composer.phar update
```
## RabbitMQ / AMQP additions
The `AmqpAwareEventDispatcher` class inherits from the standard `EventDispatcher` class and adds a thin layer for dispatching events to your [RabbitMQ](http://www.rabbitmq.com/) or any other messaging system based on the [AMQP](http://www.amqp.org/) standard.
If you fire an event of type `QueueEvent` the `AmqpAwareEventDispatcher` will dipatch it to your message queue after all other regular listeners have been processed. Any other event (which does not inherit from `QueueEvent`) won't be dispatched the message queue, so it's fully compatible to the standard event dispatcher.
### Usage examples
``` php
setQueueName('my-queue');
// Dispatch it
$dispatcher = new AmqpAwareEventDispatcher();
$dispatcher->dispatch('my-event', $event);
```
This is a pretty basic usage example: It creates a new `QueueEvent` object with a string "PING!" as subject. When it's dispatched by the event dispatcher, it will be send to the AMQP compatible message queue at `localhost` on port `5672`. It will be delivered via a direct exchange to the queue "my-queue".
Of course, you can fully customize your connection parameters and the way how the message will be delivered:
``` php
array(
'name' => 'my-exhange',
'type' => 'fanout',
'passive' => false,
'exclusive' => false,
'durable' => true,
'auto_delete' => false,
),
'queue' => array(
'name' => 'my-queue',
'passive' => false,
'durable' => true,
'exclusive' => false,
'auto_delete' => false,
),
));
$dispatcher->dispatch('my-event', $event);
```
If your subject is anything other than a string, the `AmqpAwareEventDispatcher` will try to serialize it for you before delivering it through the message queue. The following rules apply here:
* If the event subject is from type **array**, it will be sent as [JSON](http://www.json.org/)-encoded string with content type `application/json`
* If the event subject is from type **object**, `AmqpAwareEventDispatcher` searches for the methods `toArray` and `asArray` which would return an array representation of said object. If one of those methods could be found, it will be sent as array (see above)
* If the event subject is from type **object** and does neither have a `toArray` nor `asArray` method, it will be `serialize()`'d and sent with content type `text/plain`
* Any **other type** will be sent as its string value with content type `text/plain`
For example, consider the following simple model/entity class:
``` php
username = $username;
$this->email = $email;
}
public function toArray()
{
return array(
'username' => $this->username,
'email' => $this->email,
);
}
// more methods ...
}
```
Noticed the `toArray` method? Now, we'll use a `User` object as event subject:
``` php
dispatch('myapp.user-event', $event);
```
This will result in the following serialized message body (content type: `application/json`):
"{"username":"johndoe","email":"[email protected]"}"
For full control for sending messages, you can use a provide a custom publisher as optional thrid parameter to `AmqpAwareEventDispatcher::dispatch()`. Your custom publisher can be any valid PHP callable, like a closure:
``` php
dispatch('myapp.user-event', $event, function($event, $conn) {
$channel = $conn->channel();
// You're on your own here ...
$channel->close();
});
```
### Routing keys
At the moment, the event name is used as routing key. Therefore it's recommended to use kind of a [reverse domain name notation](http://en.wikipedia.org/wiki/Reverse_domain_name_notation) style for your event names (which is also a best practice used in Symfony), if you want to use [topic exchanges](http://www.rabbitmq.com/tutorials/tutorial-five-python.html):
``` php
dispatch('myapp.user.upload.avatar', new QueueEvent($subject));
```
If you are using a custom publisher, you can retrieve the routing key by using `$event['routing_key']`.
## Copyright
Copyright (c) 2012 Pascal Cremer (b00gizm). See LICENSE for details.