Event-schema is a tool to validate and process messages from a broker or between microservices.
"require": {
"micronative/event-schema": "^1.0.1"
},
"repositories": [
{ "type": "vcs", "url": "https://github.com/micronative/event-schema" }
],
Run
composer require micronative/event-schema:1.0.1
The code under samples is a mock microservice architecture:
- a MessageBroker
- two microservices: UserService and TaskService
In this sample, UserService is a producer and TaskService is a consumer. When a User created or updated on UserService, it will use Micronative\EventSchema\Validator to validate the event then publish it to MessageBroker. TaskService is listening to these events and use Micronative\EventSchema\Consumer to process the incoming events.
- event: User.Created
version: 1.0.0
schema: /assets/schemas/User.Created.schema.json
- event: User.Updated
version: 2.0.0
schema: /assets/schemas/User.Updated.schema.json@see: samples/UserService/assets/configs/events.yml
<?php
namespace Samples\UserService;
use Micronative\EventSchema\Validator;
use Micronative\MockBroker\Broker;
use Micronative\MockBroker\Publisher as MockPublisher;
use Samples\UserService\Messaging\Publisher;
use Samples\UserService\Entities\User;
use Samples\UserService\Events\UserEventSubscriber;
use Samples\UserService\Repositories\UserRepository;
use Symfony\Component\EventDispatcher\EventDispatcher;
class UserApp
{
private UserRepository $userRepository;
/**
* UserApp constructor.
* @param \Micronative\MockBroker\Broker|null $broker
* @throws \Micronative\EventSchema\Exceptions\ConfigException
* @throws \Micronative\EventSchema\Exceptions\JsonException
*/
public function __construct(Broker $broker = null)
{
$eventSubscriber = new UserEventSubscriber(
new Publisher(
new MockPublisher($broker),
new Validator(dirname(__FILE__), ["/assets/configs/out_events.yml"]))
);
$eventDispatcher = new EventDispatcher();
$eventDispatcher->addSubscriber($eventSubscriber);
$this->userRepository = new UserRepository($eventDispatcher);
}
/**
* @param string $name
* @param string|null $email
* @throws \Exception
*/
public function createUser(string $name, ?string $email = null)
{
$this->userRepository->save(new User($name, $email));
}
/**
* @param \Samples\UserService\Entities\User $user
* @throws \Exception
*/
public function updateUser(User $user, string $name, string $email)
{
$user->setName($name)->setEmail($email);
$this->userRepository->update($user);
}
}@see: Samples\UserService\UserApp
<?php
namespace Samples\UserService\Repositories;
use Ramsey\Uuid\Uuid;
use Samples\UserService\Entities\User;
use Samples\UserService\Events\UserEvent;
use Symfony\Component\EventDispatcher\EventDispatcherInterface;
class UserRepository
{
private EventDispatcherInterface $eventDispatcher;
/**
* UserRepository constructor.
* @param \Symfony\Component\EventDispatcher\EventDispatcherInterface $eventDispatcher
*/
public function __construct(EventDispatcherInterface $eventDispatcher)
{
$this->eventDispatcher = $eventDispatcher;
}
/**
* @param \Samples\UserService\Entities\User $user
* @throws \Exception
*/
public function save(User $user)
{
// save user then dispatch event
$this->eventDispatcher->dispatch(
new UserEvent(UserEvent::USER_CREATED, UserEvent::VERSION, Uuid::uuid4()->toString(), $user->toArray()),
UserEvent::USER_CREATED
);
}
/**
* @param \Samples\UserService\Entities\User $user
* @throws \Exception
*/
public function update(User $user)
{
// update user then dispatch event
$this->eventDispatcher->dispatch(
new UserEvent(UserEvent::USER_UPDATED, UserEvent::VERSION, Uuid::uuid4()->toString(), $user->toArray()),
UserEvent::USER_UPDATED
);
}
}@see: Samples\UserService\Repositories\UserRepository
<?php
namespace Samples\UserService\Events;
use Samples\UserService\Messaging\Publisher;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
class UserEventSubscriber implements EventSubscriberInterface
{
private Publisher $publisher;
public function __construct(Publisher $publisher)
{
$this->publisher = $publisher;
}
public static function getSubscribedEvents()
{
return [
UserEvent::USER_CREATED => 'onUserCreated',
UserEvent::USER_UPDATED => 'onUserUpdated',
];
}
public function onUserCreated(UserEvent $userEvent)
{
$this->publisher->publishEvent($userEvent);
}
public function onUserUpdated(UserEvent $userEvent)
{
$this->publisher->publishEvent($userEvent);
}
}@see: Samples\UserService\Events\UserEventSubscriber
<?php
namespace Samples\UserService\Messaging;
use Micronative\EventSchema\ValidatorInterface;
use Samples\UserService\Events\UserEvent;
use Micronative\MockBroker\PublisherInterface as MockPublisherInterface;
class Publisher implements PublisherInterface
{
private ValidatorInterface $validator;
private MockPublisherInterface $publisher;
/**
* @param MockPublisherInterface $publisher
* @param ValidatorInterface|null $validator
*/
public function __construct(MockPublisherInterface $publisher, ValidatorInterface $validator = null)
{
$this->validator = $validator;
$this->publisher = $publisher;
}
public function publishEvent(UserEvent $userEvent)
{
echo "-- Validating outgoing event message: {$userEvent->getName()}" . PHP_EOL;
if ($this->validator->validate($userEvent, true)) {
echo "-- Start publishing event message to broker: {$userEvent->getName()}" . PHP_EOL;
$this->publisher->publish($userEvent->toJson(), UserEvent::USER_EVENT_TOPIC);
echo "-- Finish publishing event message to broker: {$userEvent->getName()}" . PHP_EOL;
}
}
}@see: Samples\UserService\Events\Messaging\Publisher
- event: User.Created
version: 1.0.0
schema: /assets/schemas/User.Created.schema.json
services:
- CreateTaskForNewUser
- SendNotificationToNewUser
- event: User.Created
version: 2.0.0
schema: /assets/schemas/User.Created.schema.json
services:
- CreateTaskForNewUser
- SendNotificationToNewUser
- event: User.Updated
schema: /assets/schemas/User.Updated.schema.json
services:
- CreateTaskForUpdatedUser
- SendNotificationToUpdatedUser@see: samples/TaskService/assets/configs/events.yml
- service: Samples\TaskService\Services\CreateTaskForNewUser
alias: CreateTaskForNewUser
callbacks:
- LogTask
- service: Samples\TaskService\Services\SendNotificationToNewUser
alias: SendNotificationToNewUser
schema: /assets/schemas/services/SendNotifcation.json
callbacks:
- LogNotification
- service: Samples\TaskService\Services\SendNotificationToUpdatedUser
alias: SendNotificationToUpdatedUser
callbacks:
- LogNotification
- service: Samples\TaskService\Services\CreateTaskForUpdatedUser
alias: CreateTaskForUpdatedUser
callbacks:
- LogTask
- service: Samples\TaskService\Services\LogTask
alias: LogTask
- service: Samples\TaskService\Services\LogNotification
alias: LogNotification@see: samples/TaskService/assets/configs/services.yml
<?php
namespace Samples\TaskService;
use Micronative\EventSchema\Processor;
use Micronative\MockBroker\Broker;
use Micronative\MockBroker\Consumer;
use Micronative\MockBroker\ConsumerInterface;
use Samples\TaskService\Events\TaskEvent;
class TaskApp
{
const USER_EVENT_TOPIC = 'User.Events';
private ConsumerInterface $consumer;
private Processor $processor;
/**
* App constructor.
* @param \Micronative\MockBroker\Broker|null $broker
* @throws \Micronative\EventSchema\Exceptions\ConfigException
* @throws \Micronative\EventSchema\Exceptions\JsonException
*/
public function __construct(Broker $broker = null)
{
$this->consumer = new Consumer($broker);
$container = new Container();
$this->processor = new Processor(
dirname(__FILE__),
["/assets/configs/events.yml"],
["/assets/configs/services.yml"],
$container
);
}
/**
* @throws \Micronative\EventSchema\Exceptions\ProcessorException
* @throws \Micronative\EventSchema\Exceptions\JsonException
* @throws \Micronative\EventSchema\Exceptions\ServiceException
* @throws \Micronative\EventSchema\Exceptions\ValidatorException
*/
public function listen()
{
$message = $this->consumer->consume(self::USER_EVENT_TOPIC);
if (!empty($message)) {
$taskEvent = (new TaskEvent())->fromJson($message);
echo "-- Start processing event: {$taskEvent->getName()}" . PHP_EOL;
$this->processor->process($taskEvent);
echo "-- Finish processing event: {$taskEvent->getName()}" . PHP_EOL;
}
}
}