[LiveComponent] Passing an entire object (not an entity) to listeners

[gremo]

[LiveComponent] Passing an entire object (not an entity) to listeners

[smnandre]

As stated in the documentation, emit() only accept some scalars in the array, so you won't be able to pass "new Notification()" like that (at least not a specific instance)

You can also pass extra (scalar) data to the listeners

So i see two potential options (there may be more):

• if you persist your Notification in any way, you can use ParamConverters as you identified
• you also could play with "hydrateWith / desydrateWith" (see this section in the documentation)

Last "option" / "alternative": if you dispatch this Event from PHP, and only listen to it in another PHP class... you could also use a standard EventDispatcher and avoid a maybe-unwanted roundtrip via the front-end (not sure if applicable in your case, but sometimes it can be a good idea)

[gremo]

@smnandre thanks for the idea. Do the hydrateWith / dehydrateWith process occurs also when using #[LiveArg]? For what I understand from the docs, it seems that the process is used only when passing props to the component....

[smnandre]

There may be a better way, but i tried something and i believe it suits your needs :

Twig Component

#[AsLiveComponent('Foo')]
class Foo extends AbstractController
{
    use DefaultActionTrait;
    use ComponentToolsTrait;

    #[LiveAction]
    public function bar(): void
    {
        $this->emit('FooBar', ['notification' => new Notification('Hello', 'World!')]);
    }

    #[LiveListener('FooBar')]
    public function onFooBar(
        #[LiveArg('notification')] #[ValueResolver(NotificationResolver::class)] Notification $notification
    )
    {
        dump($notification);
    }
}

Twig Template

<div {{ attributes.defaults({}) }}>

    <button
        type="button"
        data-action="live#action"
        data-action-name="bar()"
    >BAR</button>

</div>

Notification DTO

class Notification
{
    public function __construct(
        public string $title,
        public string $message,
    ) {
    }

    public function getTitle(): string
    {
        return $this->title;
    }

    public function getMessage(): string
    {
        return $this->message;
    }
}

And a little ValueResolver

class NotificationResolver implements ValueResolverInterface
{
    public function resolve(Request $request, ArgumentMetadata $argument): array
    {
        if (Notification::class !== $argument->getType()) {
            return [];
        }

        if (!is_array($attribute = $request->attributes->get($argument->getName()))) {
            return [];
        }

        if (!isset($attribute['title']) || !isset($attribute['message'])) {
            return [];
        }

        if (!is_string($attribute['title']) || !is_string($attribute['message'])) {
            throw new NotFoundHttpException(sprintf('The notification for the "%s" parameter is invalid.', $argument->getName()));
        }

        return [new Notification($attribute['title'], $attribute['message'])];
    }
}

And when you click on the button, the live action is called, the event is emitted, and you can get the notification object as you wanted.

Requests	Debug