ClassTag instead of Class parameter, #1 #194
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| @@ -32,12 +36,14 @@ object AggregateEventTag { | |||
| * same entity will be produced by different event streams and handled by different shards in the read side | |||
| * processor, leading to out of order event handling. | |||
| * | |||
| * @param eventType The type of the event. | |||
| * @tparam eventType The type of the event. | |||
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Should this be @tparam Event?
| @@ -49,13 +55,18 @@ object AggregateEventTag { | |||
| * same entity will be produced by different event streams and handled by different shards in the read side | |||
| * processor, leading to out of order event handling. | |||
| * | |||
| * @param eventType The type of the event. | |||
| * @tparam eventType The type of the event. | |||
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Again here, should it be @tparam Event?
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| @@ -108,6 +109,11 @@ abstract class AbstractPersistentEntityRegistry(system: ActorSystem, injector: I | |||
| throw new IllegalArgumentException(s"[${entityClass.getName} must first be registered") | |||
| } | |||
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| override def refFor2[C, P <: PersistentEntity[C, _, _]: ClassTag](entityId: String): PersistentEntityRef[C] = { | |||
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@jroper The attempt with abstract type members breaks down completely (as far as I can see) when trying to use it with the PersistentEntityTestDriver. I think that approach is going down a rabbit hole. You can see the problems by testkit-scaladsl/test:compile in https://github.com/patriknw/lagom/tree/wip-scaladsl-ClassTag-NOT-WORKING-patriknw
I was thinking that we could at least try ClassTag for refFor and that would require two parameters like this, kind of repeating the command type. That is maybe not bad, but I'm not sure. You can see usage here: https://github.com/lagom/lagom/pull/194/files#diff-5b233e73c9b93c20d145f9ecd318b512R143
WDYT?
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rebased, let's merge the "ClassTag instead of Class parameter in AggregateEvent" and get back to |
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@jroper It's possible to use ClassTag for the PersistentEntityRegistry by using abstract type members in
PersistentEntity. One drawback to be aware of is that there is no clear compilation error if one forgets to override the type members. See 0127520There is one more challenge, which I have not solved yet.
ReadSide.register. There we have the additional relationshipEvent <: AggregateEvent[Event]