Allow for clean extension of factories

[lstrojny]

We needed to re-add runtime embeddeds and links again. In order to do so, we override the EmbeddedsFactory and LinksFactory with class extending each. That’s a bit unclean and a cleaner way would be to decorate the original classes. To enable that, one would need to introduce two interface Hateoas\Factory\EmbeddedsFactoryInterface and Hateoas\Factory\LinksFactoryInterface:

interface EmbeddedsFactoryInterface
{
    /** @return Embedded[] */
    public function create(object $object, SerializationContext $context): array;
}

interface LinksFactoryInterface
{
    /** @return Link[] */
    public function create(object $object, SerializationContext $context): array;
}

Then change the AddRelationsListener to use these new interfaces instead of the concrete classes. Would you be interested in this change?

[goetas]

I personally would like to avoid having relations added at runtime. I prefer to declare relations when possible and then allow to exclude them at runtime. The main advantages of this approach is that is possible to generate OpenAPI documentation of those models. (example is NelmioApiDoc Bundle). When relations are declared at runtime, that is not possible anymore.

I understand that for some projects that might be not easy, but in this library I would like that ppl start thinking in that direction.

[lstrojny]

Just to note: I get that and I am not proposing adding the ability for runtime relations but instead being able to add capabilities like that in a clean way.

[goetas]

@lstrojny sorry for the misunderstanding, but yes that sounds a good idea. this change needs also some adaptations in the builder class to allow you to pass the custom implementation of the factories, right?

[lstrojny]

Yup, that seems necessary. Since the EmbeddsFactory and the LinksFactory have a few dependency, one could either inject factory factories or the class name of the factories. The latter would limit adding new dependencies in an extension while the former is quite a bit complicated. Any opinions?