IMO this is a bit too specific functionality, and the implementation is very opinionated.

Maybe create a bundle instead?

I use this in my projects:

class WorkflowLogListener implements EventSubscriberInterface
{
    private $em;

    public function __construct(EntityManagerInterface $em)
    {
        $this->em = $em;
    }

    /**
     * {@inheritdoc}
     */
    public static function getSubscribedEvents()
    {
        return [
            'workflow.completed' => 'completed',
        ];
    }

    public function completed(Event $event)
    {
        $subject = $event->getSubject();

        $log = new WorkflowLog();
        $log
            ->setSubjectClass(get_class($subject))
            ->setSubjectId($subject->getId())
            ->setWorkflow($event->getWorkflowName())
            ->setTransition($event->getTransition()->getName())
            ->setFroms($event->getTransition()->getFroms())
            ->setTos($event->getTransition()->getTos())
        ;

        $this->em->persist($log);
        $this->em->flush();
    }
}

Sure, but that isn't on the entity itself

Not sure why that is a problem. Create a repository, add a method to select based on the entity(class and id), use that in the controller to fetch results.

or put three extra lines in your workflow config. If you need more detailed log, then create your own listener.

Your solution poses some problems:

• you have to log every transition change across ALL of your workflows, even on a workflow you may not want to log. That could be a lot of wasted database rows
• event listener priority: by having a listener to store a log entity it makes it more difficult for logic to fire based on an entity's history (does the listener that checks the logic fire after the log listener, or before or?) Incidently this is how I first solved the need too but the priority was an ugly issue. However, using this way, you can have a listener for the entered event and know that the history has been set.

Hi, generaly a workflow state is binded to a status of an entity

I do something like this on most of my workflow entities when i want to track status change on specific entity, to answer your Sure, but that isn't on the entity itself

    // the setStatus is called by our implementation of MarkingStoreInterface
    public function setStatus(int $status): self
    {
        $this->status = $status;
        $this->statusLogRecords->add(new MyEntityLog($this));

        return $this;
    }

And the MyEntityLog have properties like the status (taken from $this), a Gedmo Timestampable (on create) and Blameable (on create), the target entity etc

This PR #29146 will also allow us to add some context, like a comment, to this log if you need documentation or whatever when the state changes :)

I totally agree with @noniagriconomie
This is also the solution in mentioned in #28253 (comment)

I'm really sorry to close your first PR on Symfony, but I can not merge this PR because we are several to prefer the solution proposed by @noniagriconomie

Anyway, Thanks for your work.