Panache support for not initialized proxies

[suchwerk]

Description
The use-case is to add not-initilized proxies to a set inside a panache entity. Right now i have to inject the entity manager to access getReference. It would be nice if PanacheEntityBase itself would implement getReference.

So

    @Inject
    EntityManager entityManager;
    ids.forEach(id->list.add(entityManager.getReference(Item.class, id)) );

to be replaced by something like:

    ids.forEach(id->list.add(Item.getReference(id)));

[Sanne]

I agree, this would be very useful. Thanks for opening!

@FroMage : I suppose this is doable?

[FroMage]

You can use Panache.getEntityManager() as well. But yeah, probably we could add this feature, but is it really common enough, do you think @Sanne ?

[suchwerk]

I guess only passing ids from a webapi is not that unusual and:

 ids.forEach(id->list.add(Item.getReference(id)));

looks leaner vs.

 ids.forEach(id->list.add(Panache.getEntityManager().getReference(Item.class, id)));

[FroMage]

Sure, I don't question that. But we don't want to add every Hibernate feature in a Panache layer because that would make the API huge and scary. So we always try to resist additions to the most common use-cases that people need. Hence my question to @Sanne but perhaps @emmanuelbernard has an idea too.

[Sanne]

You can't easily update collections without this .. so yes I'd say it's commonly useful. As many other things :)

[Sanne]

Although TBH Panache.getEntityManager().getReference(.. doesn't look too bad - your call @FroMage

[FroMage]

If I give you Entity getReference(Object id), I'll have to give you List<Entity> getReferences(Object... ids) too because ids.forEach(id->list.add(Item.getReference(id))); is just yuck compared to Item.getReferences(ids).

[emmanuelbernard]

Hum, getReference is a relatively useful optimisation but using it to get loads of entities to add to a List is less common.
Personally I'm getting scared of Panache's own weight and would resist adding these two features. But I might in my ivory tower.

[loicmathieu]

I tend to agree with @emmanuelbernard, then people will want findReference(query, params) with all the variations because, you usually list via a query not via known ids ...

@suchwerk what do you do with those references you get ? Maybe we're missing a different functionality here ?

[suchwerk]

@loicmathieu I just want to add them to a jointable.

[ryckowski]

I'm using myEntity.setRelated(getReference(Related.clas, id)) quite often to set the related entity and there's no reason fetch it. From sql point of view just want to set foreign key id which I know
Is there a better practise?

[gavinking]

Hum, getReference is a relatively useful optimisation but using it to get loads of entities to add to a List is less common.

I agree but it looks like the mentioned usage is a bit misleading?

All that's described is adding Item.getReference(id), which is definitely needed IMO. (Nothing specific to lists in that.)

[gaetanBloch]

Just discussed this issue with @yrodiere and will work on a PR on Panache in a near future!