Sysmfony REST API hash id of entities

Question

I'm building a multitenancy backend using Symfony 2.7.9 with FOSRestBundle and JMSSerializerBundle.

When returning objects over the API, I'd like to hash all the id's of the returned objects, so instead of returning { id: 5 } it should become something like { id: 6uPQF1bVzPA } so I can work with the hashed id's in the frontend (maybe by using http://hashids.org)

I was thinking about configuring JMSSerializer to set a virtual property (e.g. '_id') on my entities with a custom getter-method that calculates the hash for the id, but I don't have access to the container / to any service.

How could I properly handle this?

Answer 1

Thanks a lot for your detailed answer qooplmao.

However, I don't particularly like this approach because I don't intend to store the hashed in the entity. I now ended up subscribing to the serializer's onPostSerialize event in which I can add the hashed id as follows:

use JMS\Serializer\EventDispatcher\EventSubscriberInterface;
use JMS\Serializer\EventDispatcher\ObjectEvent;
use Symfony\Component\DependencyInjection\ContainerInterface;

class MySubscriber implements EventSubscriberInterface
{
    protected $container;

    public function __construct(ContainerInterface $container)
    {
        $this->container = $container;
    }

    public static function getSubscribedEvents()
    {
        return array(
            array('event' => 'serializer.post_serialize', 'method' => 'onPostSerialize'),
        );
    }

    /**
     * @param ObjectEvent $event
     */    
    public function onPostSerialize(ObjectEvent $event)
    {
        $service = $this->container->get('myservice');
        $event->getVisitor()->addData('_id', $service->hash($event->getObject()->getId()));
    }
}