malocher/zf2-event-store-module

EventStore integration for Zend Framework 2

dev-master 2014-01-26 20:07 UTC

Requires

• php: >=5.4.0
• jms/serializer: 0.14.*
• malocher/event-store: dev-master
• zendframework/zendframework: 2.*

Requires (Dev)

• phpunit/phpunit: 3.7.*

BSD-3-Clause

• Alexander Miertsch
• Manfred Weber

• framework
• zf2
• ddd
• EventSourcing
• EventStore

README

Zend Framework 2 Module that integrates the Malocher EventStore in your ZF2 application.

Installation

Installation of MalocherEventStoreModule uses composer. For composer documentation, please refer to getcomposer.org. Add following requirement to your composer.json

"malocher/zf2-event-store-module" : "dev-master"

Then add MalocherEventStoreModule to your config/application.config.php

Installation without composer is not officially supported, and requires you to install and autoload the dependencies specified in the composer.json.

Setup

Setup the EventStore using your module or application configuration. Put all EventStore options under the key malocher.eventstore.

  'malocher.eventstore' => array(
        ...
  )

The MalocherEventStoreModule ships with an Zf2EventStoreAdapter. You can setup the ZF2 DB Adapter via the malocher.eventstore.adapter.connection configuration. Use the same adapter options like you would do with a normal ZF2 DB Adapter. Checkout ZF2 docs for all available options. Here is an example that setup a SQLite in memory adapter:

'malocher.eventstore' => array(
    'adapter' => array(
        'MalocherEventStoreModule\Adapter\Zf2EventStoreAdapter' => array(
            'connection' => array(
                'driver' => 'Pdo_Sqlite',
                'database' => ':memory:'
            )
        )
    ),
)

Right now you have to create the database schema yourself. We are working on a command line tool to help you setup your EventStore. The store needs one snapshot table and an event stream table per EventSourcedObject (AggregateRoot, if your using DDD).

Here is the example schema used for SQLite:

-- create one snapshot table
CREATE TABLE snapshot 
(
    id INTEGER PRIMARY KEY,
    sourceType TEXT,
    sourceId  TEXT,
    snapshotVersion INTEGER
)

-- create a table for each of your EventSourcedObjects
-- by default My\Namespaced\Object leads to the table name object_stream
CREATE TABLE <object name here>_stream 
(
    eventId TEXT PRIMARY KEY,
    sourceId TEXT,
    sourceVersion INTEGER,
    eventClass TEXT,
    payload TEXT,
    eventVersion REAL,
    timestamp INTEGER
)

Usage

Use the ZF2 ServiceManger to get an instance of the Malocher\EventStore. A ServiceFactory passes your malocher.eventstore configuration to the EventStore, so it is ready to save and load your EventSourcedObjects.

use Malocher\EventStore\EventStore;
use Malocher\EventStore\StoreEvent\PostPersistEvent;

/* @var $eventStore EventStore */
$eventStore = $serviceManager->get('malocher.eventstore');

//You can listen to the eventstore.events_post_persist event to be notified 
//when an object was changed
$eventstore->events()->attach(PostPersistEvent::NAME, function(PostPersistEvent $e) {
    foreach ($e->getPersistedEvents() as $persitedEvent) {
        if ($persistedEvent instanceof \My\Event\UserNameChangedEvent) {
            $oldName = $persistedEvent->getPayload()['oldName'];
            $newName = $persistedEvent->getPayload()['newName'];
            echo "Name changed from $oldName to $newName";
        }
    }
});

$userRepository = $eventStore->getRepository('My\User');

//Assuming username is the primary key 
$user = $userRepository->find('John');

$user->changeName('Malocher');

$userRepository->save($user);

//Output: Name changed from John to Malocher

ZF2 integration

In the last example we've shown how to listen to the PostPersistEvent of the EventStore. We've used $eventStore->events()->attach(...), which is an important difference to the original EventStore implementation. By default the Malocher EventStore uses a Symfony EventDispatcher, but for the ZF2 version we've replaced it with an ZF2 EventManagerProxy. You can add listeners the ZF2 way or the Symfony way, it's up to you. The good news is, that you can work with the flexible concepts of SharedEventCollections by attaching a listener via ZF2 SharedEventManager.

use Malocher\EventStore\EventStore;
use Malocher\EventStore\StoreEvent\PostPersistEvent;

//in a module bootstrap
$sharedEventManager = $serviceManager->get('SharedEventManager');

$sharedEventManager->attach(
    'EventStore',
    PostPersistEvent::NAME,
    function(PostPersistEvent $e) {
    foreach ($e->getPersistedEvents() as $persitedEvent) {
        if ($persistedEvent instanceof \My\Event\UserNameChangedEvent) {
            $oldName = $persistedEvent->getPayload()['oldName'];
            $newName = $persistedEvent->getPayload()['newName'];
            echo "Name changed from $oldName to $newName";
        }
    }
);

//somewhere else in your application ...

$userRepository = $eventStore->getRepository('My\User');

//Assuming username is the primary key 
$user = $userRepository->find('John');

$user->changeName('Malocher');

$userRepository->save($user);

//Output: Name changed from John to Malocher