[Workflow] Add EventNameTrait to compute event name strings in subscribers

[squrious]

Q	A
Branch?	7.1
Bug fix?	no
New feature?	yes
Deprecations?	no
Issues	N/A
License	MIT

Hello!

Using the event dispatcher, we usually use event's class name to configure the event to listen to. For workflow, we
still have to use raw strings:

class WorkflowPostSubscriber implements EventSubscriberInterface
{
    public static function getSubscribedEvents(): array
    {
        return [
            'workflow.post.entered.published' => 'onPublishedEntered',        
        ];
    }
}

Using class names is more clear about what event we use (easier to know which event to use in the listener). Even if we already have attributes to define event listeners, the event subscriber way could be improved.

Proposal

This PR adds a trait to improve DX when using workflow events in event subscribers.

class WorkflowPostSubscriber implements EventSubscriberInterface
{
    public static function getSubscribedEvents(): array
    {
        return [
            PublishedEvent::get(workflowName: 'post', placeName: 'entered') => 'onPublishedEntered',        
        ];
    }
}

For a better DX, the EventNameTrait provides two methods: getNameForPlace and getNameForTransition, so the second
argument of ::get and its PHPDoc are consistent with the event type.

In event classes, it is used like:

class EnterEvent extends Event
{
    use EventNameTrait {
        use getNameForPlace as public get;
    }

    // ...
}

Cheers!

[lyrixx]

Did you see #51210?

[squrious]

Did you see #51210?

Yes! But as event subscribers allow to register events too, shouldn't we take care of their DX too? Or maybe I could leverage the existing code for this?

[lyrixx]

IMHO, event listener are better thank event subscriber now.

But I think we can do something for the subscriber too. I'll review it

[derrabus]

But as event subscribers allow to register events too, shouldn't we take care of their DX too?

No. I'd rather get rid of subscribers, tbh. From my POV, the only reason subscribers still exist, is the amount of busy work we would force upon downstream code if we removed them. Regarding DX improvements, I'd keep our efforts focused on attribute-based listeners.

[lyrixx]

@derrabus with SF full stack, it's easy to register listener, but without the framework, it's harder. I think it's still better to merge this PR once ready

[squrious]

Thanks for your feedback! I addressed your comments :)

[lyrixx]

Can you add a note in the CHANGELOG ?

👍🏼

[squrious]

Can you add a note in the CHANGELOG ?

👍🏼

Done!

[lyrixx]

Thanks

[fabpot]

Suggested change

	* Get event name for workflow and transition.
	* Gets the event name for workflow and transition.

[fabpot]

Suggested change

	* Get event name for workflow and place.
	* Gets the event name for workflow and place.

[fabpot]

Thank you @squrious.