Preparing events | laravel-event-sourcing | Spatie

 SPATIE

  Laravel Event Sourcing
=========================

spatie.be/open-source

  [Docs](https://spatie.be/docs)  [Laravel-event-sourcing](https://spatie.be/docs/laravel-event-sourcing/v6)  Advanced-usage  Preparing events

 Version   v7   v6   v5   v4   v3   v2   v1

 Other versions for crawler [v7](https://spatie.be/docs/laravel-event-sourcing/v7) [v6](https://spatie.be/docs/laravel-event-sourcing/v6) [v5](https://spatie.be/docs/laravel-event-sourcing/v5) [v4](https://spatie.be/docs/laravel-event-sourcing/v4) [v3](https://spatie.be/docs/laravel-event-sourcing/v3) [v2](https://spatie.be/docs/laravel-event-sourcing/v2) [v1](https://spatie.be/docs/laravel-event-sourcing/v1)

- [ Introduction ](https://spatie.be/docs/laravel-event-sourcing/v6/introduction)
- [ Support us ](https://spatie.be/docs/laravel-event-sourcing/v6/support-us)
- [ Requirements ](https://spatie.be/docs/laravel-event-sourcing/v6/requirements)
- [ Installation & setup ](https://spatie.be/docs/laravel-event-sourcing/v6/installation-setup)
- [ Questions and issues ](https://spatie.be/docs/laravel-event-sourcing/v6/questions-issues)
- [ Changelog ](https://spatie.be/docs/laravel-event-sourcing/v6/changelog)
- [ Upgrading ](https://spatie.be/docs/laravel-event-sourcing/v6/upgrading)
- [ Resources and alternatives ](https://spatie.be/docs/laravel-event-sourcing/v6/resources-and-alternatives)
- [ About us ](https://spatie.be/docs/laravel-event-sourcing/v6/about-us)

Getting familiar with event sourcing
------------------------------------

- [ Introduction ](https://spatie.be/docs/laravel-event-sourcing/v6/getting-familiar-with-event-sourcing/introduction)
- [ The traditional application ](https://spatie.be/docs/laravel-event-sourcing/v6/getting-familiar-with-event-sourcing/the-traditional-application)
- [ Using projectors to transform events ](https://spatie.be/docs/laravel-event-sourcing/v6/getting-familiar-with-event-sourcing/using-projectors-to-transform-events)
- [ Using aggregates to make decisions based on the past ](https://spatie.be/docs/laravel-event-sourcing/v6/getting-familiar-with-event-sourcing/using-aggregates-to-make-decisions-based-on-the-past)

Using projectors
----------------

- [ Writing your first projector ](https://spatie.be/docs/laravel-event-sourcing/v6/using-projectors/writing-your-first-projector)
- [ Creating and registering projectors ](https://spatie.be/docs/laravel-event-sourcing/v6/using-projectors/creating-and-configuring-projectors)
- [ Making sure events get handled in the right order ](https://spatie.be/docs/laravel-event-sourcing/v6/using-projectors/making-sure-events-get-handled-in-the-right-order)
- [ Thinking in events ](https://spatie.be/docs/laravel-event-sourcing/v6/using-projectors/thinking-in-events)

Using reactors
--------------

- [ Writing your first reactor ](https://spatie.be/docs/laravel-event-sourcing/v6/using-reactors/writing-your-first-reactor)
- [ Creating and configuring reactors ](https://spatie.be/docs/laravel-event-sourcing/v6/using-reactors/creating-and-configuring-reactors)

Using aggregates
----------------

- [ Writing your first aggregate ](https://spatie.be/docs/laravel-event-sourcing/v6/using-aggregates/writing-your-first-aggregate)
- [ Creating and configuring aggregates ](https://spatie.be/docs/laravel-event-sourcing/v6/using-aggregates/creating-and-configuring-aggregates)
- [ Testing aggregates ](https://spatie.be/docs/laravel-event-sourcing/v6/using-aggregates/testing-aggregates)
- [ Snapshots ](https://spatie.be/docs/laravel-event-sourcing/v6/using-aggregates/snapshots)

Advanced usage
--------------

- [ Preparing events ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/preparing-events)
- [ Replaying events ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/replaying-events)
- [ Storing metadata ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/storing-metadata)
- [ Handling exceptions ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/handling-exceptions)
- [ Discovering projectors and reactors ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/discovering-projectors-and-reactors)
- [ Using your own event storage model ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/using-your-own-event-storage-model)
- [ Using your own event storage repository ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/using-your-own-event-storage-repository)
- [ Using your own event serializer ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/using-your-own-event-serializer)
- [ Using aliases for stored event classes ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/using-aliases-for-stored-event-classes)
- [ Adding and Removing Projectors and Reactors ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/adding-and-removing-projectors-and-reactors)
- [ Aggregate Partials ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/aggregate-partials)
- [ Event Queries ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/event-queries)
- [ Commands ](https://spatie.be/docs/laravel-event-sourcing/v6/advanced-usage/commands)

      You are viewing the documentation for **an older version** of this package. You can check the version you are using with the following command:

 `                                    composer show spatie/laravel-event-sourcing                                                                                                                                                                                                                                    `

Preparing events
================

###  On this page

1. [ Specifying a queue ](#content-specifying-a-queue)

The package will listen for events that implement the `\Spatie\EventSourcing\ShouldBeStored` interface. This is an empty interface that simply signals to the package that the event should be stored.

You can quickly create an event that implements `ShouldBeStored` by running this artisan command:

```
php artisan make:storable-event NameOfYourEvent
```

Here's an example of such event:

```
namespace App\Events;

use Spatie\EventSourcing\StoredEvents\ShouldBeStored;

class MoneyAdded extends ShouldBeStored
{
    /** @var string */
    public $accountUuid;

    /** @var int */
    public $amount;

    public function __construct(string $accountUuid, int $amount)
    {
        $this->accountUuid = $accountUuid;

        $this->amount = $amount;
    }
}
```

Whenever an event that implements `ShouldBeStored` is fired it will be serialized and written in the `stored_events` table. Immediately after that, the event will be passed to all projectors and reactors.

Specifying a queue
--------------------------------------------------------------------------------------------------------------

When a `StoredEvent` is created, we'll dispatch a job on the queue defined in the `queue` key of the `event-sourcing` config file. Queued projectors and reactors will get called when the job is executed on the queue.

On an event you can override the queue that should be used by adding a `queue` property.

```
namespace App\Events;

use Spatie\EventSourcing\StoredEvents\ShouldBeStored;

class MyEvent extends ShouldBeStored
{
    public $queue = 'alternativeQueue';

    ...
}
```