question: how would i annotate a relation that i only want to lookup if included

For, example, let’s say events have associated users. So, we have

@JsonApiResource(type='events')
public class EventResource {
  @JsonApiRelation(serialize = SerializeType.ONLY_ID)
  UserResource user
}

So, I want to be be able to say /events/1 to do a query against the events service, which gives us back events with a userId, so then the resulting json has relationships with { "data": { "id": "1", "type": "users" } }

I also want to be able to say /events/1?include=user to do a query against the events service AND a query against the user service, so now i have a full user object to include, so a "included": [ { "id": "1", "type": "users", "attributes": {...} } ]

Even if there was a LoopIncludeBehavior of Always call a relationship's findManyTargets or findOneTarget if the field is included, that wouldn’t be quite right, because I actually want to utilize the userId that I already have off of the event object, almost like a /users/1 call, rather than do a query against the user service using the event id.

Any thoughts on how the framework wants me to go about doing this?

[mohlek]

I was thinking of something like this:

@JsonApiResource(type='events')
public class EventResource {
   @JsonApiRelation( idField = "userId" )
   UserResource user

   String userId
}

[remmeier]

maybe to clarify for non-insiders, it could then look like:

@JsonApiResource(type='events')
public class EventResource {
   @JsonApiRelation
   UserResource user
   
  @JsonApiRelationId
   String userId
}

The user attribute would then still be managed & looked-up by crnk automatically. There would be no need to speciy relationship repositories for such cases.