Recording events from AggregatePartial

[giorgiopogliani]

Hello, to give some context the scenario I was in is: trying to send a notification when a user is tagged in some content.

I created the EntryAggregateRoot which has a method to update the content updateEntryContent(string $content).

class EntryAggregateRoot extends AggregateRoot 
{
    public function updateEntryContent(string $content): self
    {
        $this->recordThat(new EntryContentUpdated($content));
        
        return $this;
    }
}

Next I created a MentionsAggregatePartial to keep things separated because I might use it on some other content column

class MentionsAggregatePartial extends AggregatePartial
{
    protected array $mentionedUsersId = [];

    public function onMentionsAdded(EntryContentUpdated $event)
    {
         // When user is tagged in content for the first time
         $this->recordThat(new UserMentioned($userId));
    }
}

Also, to be able to add partials from packages I overrode the method resolvePartials like so:

class EntryAggregateRoot extends AggregateRoot 
{
    protected function resolvePartials(): Collection
    {
        if (! isset($this->entities)) {
            return collect(static::$partials)->map(function ($partial) {
                return new $partial($this);
            });
        }
    
        return $this->entities;
    }
    // ....
}

Everything seemed to work perfectly! But only the first time, the second update triggered the exception: Could not persist aggregate EntryAggregateRoot .... because it seems to be changed by another process after it was retrieved in the current process. Expect to persist events after version 21, but version 20 was already persisted.

So I inspected the source code and I come up this change that fixed the problem:

abstract class AggregateRoot
{
    // ...
    public function recordThat(ShouldBeStored $domainEvent): static
    {
        $domainEvent
            ->setAggregateRootUuid($this->uuid)
            ->setCreatedAt(CarbonImmutable::now());
    
        $this->recordedEvents[] = $domainEvent;
    
        $this->apply($domainEvent);
    
        $domainEvent->setAggregateRootVersion($this->aggregateVersion);
    
        // Moved here the apply on the aggregate partials outside the main apply and 
        // after the set for the aggregate root version above
        foreach ($this->resolvePartials() as $partial) {
            $partial->apply($domainEvent);
        }
    
        return $this;
    }
   // ...
}

Now everything works but I am not sure if this has some consequences. Also, I cannot really do that change without reflection magic because some property on the abstract class are private.

I'll wait some comments/feedbacks, thanks!