Storing metadata | 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/v5)  Advanced-usage  Storing metadata

 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/v5/introduction)
- [ Support us ](https://spatie.be/docs/laravel-event-sourcing/v5/support-us)
- [ Requirements ](https://spatie.be/docs/laravel-event-sourcing/v5/requirements)
- [ Installation & setup ](https://spatie.be/docs/laravel-event-sourcing/v5/installation-setup)
- [ Questions and issues ](https://spatie.be/docs/laravel-event-sourcing/v5/questions-issues)
- [ Changelog ](https://spatie.be/docs/laravel-event-sourcing/v5/changelog)
- [ Upgrading ](https://spatie.be/docs/laravel-event-sourcing/v5/upgrading)
- [ Resources and alternatives ](https://spatie.be/docs/laravel-event-sourcing/v5/resources-and-alternatives)
- [ About us ](https://spatie.be/docs/laravel-event-sourcing/v5/about-us)

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

- [ Introduction ](https://spatie.be/docs/laravel-event-sourcing/v5/getting-familiar-with-event-sourcing/introduction)
- [ The traditional application ](https://spatie.be/docs/laravel-event-sourcing/v5/getting-familiar-with-event-sourcing/the-traditional-application)
- [ Using projectors to transform events ](https://spatie.be/docs/laravel-event-sourcing/v5/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/v5/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/v5/using-projectors/writing-your-first-projector)
- [ Creating and registering projectors ](https://spatie.be/docs/laravel-event-sourcing/v5/using-projectors/creating-and-configuring-projectors)
- [ Making sure events get handled in the right order ](https://spatie.be/docs/laravel-event-sourcing/v5/using-projectors/making-sure-events-get-handled-in-the-right-order)
- [ Thinking in events ](https://spatie.be/docs/laravel-event-sourcing/v5/using-projectors/thinking-in-events)

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

- [ Writing your first reactor ](https://spatie.be/docs/laravel-event-sourcing/v5/using-reactors/writing-your-first-reactor)
- [ Creating and configuring reactors ](https://spatie.be/docs/laravel-event-sourcing/v5/using-reactors/creating-and-configuring-reactors)

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

- [ Writing your first aggregate ](https://spatie.be/docs/laravel-event-sourcing/v5/using-aggregates/writing-your-first-aggregate)
- [ Creating and configuring aggregates ](https://spatie.be/docs/laravel-event-sourcing/v5/using-aggregates/creating-and-configuring-aggregates)
- [ Testing aggregates ](https://spatie.be/docs/laravel-event-sourcing/v5/using-aggregates/testing-aggregates)
- [ Snapshots ](https://spatie.be/docs/laravel-event-sourcing/v5/using-aggregates/snapshots)

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

- [ Preparing events ](https://spatie.be/docs/laravel-event-sourcing/v5/advanced-usage/preparing-events)
- [ Replaying events ](https://spatie.be/docs/laravel-event-sourcing/v5/advanced-usage/replaying-events)
- [ Storing metadata ](https://spatie.be/docs/laravel-event-sourcing/v5/advanced-usage/storing-metadata)
- [ Handling exceptions ](https://spatie.be/docs/laravel-event-sourcing/v5/advanced-usage/handling-exceptions)
- [ Discovering projectors and reactors ](https://spatie.be/docs/laravel-event-sourcing/v5/advanced-usage/discovering-projectors-and-reactors)
- [ Using your own event storage model ](https://spatie.be/docs/laravel-event-sourcing/v5/advanced-usage/using-your-own-event-storage-model)
- [ Using your own event storage repository ](https://spatie.be/docs/laravel-event-sourcing/v5/advanced-usage/using-your-own-event-storage-repository)
- [ Using your own event serializer ](https://spatie.be/docs/laravel-event-sourcing/v5/advanced-usage/using-your-own-event-serializer)
- [ Using aliases for stored event classes ](https://spatie.be/docs/laravel-event-sourcing/v5/advanced-usage/using-aliases-for-stored-event-classes)
- [ Adding and Removing Projectors and Reactors ](https://spatie.be/docs/laravel-event-sourcing/v5/advanced-usage/adding-and-removing-projectors-and-reactors)

      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                                                                                                                                                                                                                                    `

Storing metadata
================

###  On this page

1. [ Storing metadata on all events ](#content-storing-metadata-on-all-events)
2. [ Storing metadata via a projector ](#content-storing-metadata-via-a-projector)

You can add metadata, such as the `id` of the logged in user, to a stored event.

Storing metadata on all events
--------------------------------------------------------------------------------------------------------------------------------------------------

If you need to store metadata on all events you can leverage Laravel's native models events when using the `EloquentStoredEventRepository`.

You must configure the package to [use your own eloquent event storage model](/laravel-event-sourcing/v4/advanced-usage/using-your-own-event-storage-model) that extends the `EloquentStoredEvent` model. On that model you can hook into the model lifecycle hooks.

```
use Spatie\EventSourcing\StoredEvents\Models\EloquentStoredEvent;

class CustomStoredEvent extends EloquentStoredEvent
{
    public static function boot()
    {
        parent::boot();

        static::creating(function(CustomStoredEvent $storedEvent) {
            $storedEvent->meta_data['user_id'] = auth()->user()->id;
        });
    }
}
```

Storing metadata via a projector
--------------------------------------------------------------------------------------------------------------------------------------------------------

The `StoredEvent` instance will be passed on to any projector method that has a variable named `$storedEvent`. You'll also need the `StoredEventRepository` that is used by the application to update the stored event. On the `StoredEvent` instance there is a property, `meta_data`, that returns an array. You can update this array to store any metadata you like.

Here's an example:

```
namespace App\Projectors;

use Spatie\EventSourcing\EventHandlers\Projectors\Projector;
use Spatie\EventSourcing\Models\StoredEvent;
use Spatie\EventSourcing\Facades\Projectionist;
use App\Events\MoneyAdded;

class MetaDataProjector extends Projector
{
    /*
     * Here you can specify which event should trigger which method.
     */
    public array $handlesEvents = [
        MoneyAdded::class => 'onMoneyAdded',
    ];

    public function onMoneyAdded(StoredEvent $storedEvent, StoredEventRepository $repository)
    {
        if (! Projectionist::isReplaying()) {
            $storedEvent->meta_data['user_id'] = auth()->user()->id;

            $repository->update($storedEvent);
        }

        // ...
    }
}
```