Cannot get properties of Elements on remote graph with scalaGraph

Hi,

Thanks for building this nice wrapper for Scala 😄. I am currently use this on a Remote JanusGraph by calling: val scalaGraph: ScalaGraph = EmptyGraph.instance().asScala().configure(_.withRemote(DriverRemoteConnection.using(cluster, "g")))

but found I lost some syntax benefit for gremlin-scala, say, if I want to add an edge between v1 and v2, I can no logger call: val edge = v1 --- ("reference", metadata -> "EdgeTest", deleted -> false) --> v2 Exceptions below:

Edge additions not supported
java.lang.IllegalStateException: Edge additions not supported
	at org.apache.tinkerpop.gremlin.structure.Vertex$Exceptions.edgeAdditionsNotSupported(Vertex.java:175)
	at org.apache.tinkerpop.gremlin.structure.util.reference.ReferenceVertex.addEdge(ReferenceVertex.java:47)
	at gremlin.scala.ScalaVertex.addEdge(ScalaVertex.scala:65)
	at gremlin.scala.SemiEdge.$minus$minus$greater(SemiEdge.scala:4)

I believe this is the cause of EmptyGraph as a underlying graph. referring to this example: https://github.com/mpollmeier/gremlin-scala-examples/blob/master/dse-graph/src/test/scala/SimpleSpec.scala instead I have to call val a = StepLabel[Vertex]() val b = StepLabel[Vertex]() scalaGraph.V(v1.id).as(a).V(v2.id).as(b).addE(REFERENCE).from(a).to(b).property(metadata, "EdgeTest").property(deleted, false).iterate()

this is one of the examples that I cannot use nice wrapper provided by gremlin-scala when I am working on a remote graph, so wondering if i missed sth. here as I am still manipulating on a ScalaGraph or there is a better way to add vertex/edges in remote graph.

Thanks for your help in advance. Alex

[hudsonmd]

Turns out it was user error… You can modify my above example to add this unmodified serializer and it will function properly

 val cluster = Cluster.build()
      .addContactPoint(url)
      .port(port)
      .serializer(new GraphSONMessageSerializerV3d0())
      .create()

Thanks for the great work bringing gremlin to scala!

[Joe29]

@nkconnor @mpollmeier For neptune I’m using the following setup. Still new to gremlin, so not sure how much of this is specific to issues with Neptune. I sort of walked it back from using idomatic (gremlin-)scala in a lot of areas, but am still able to use the g + CC functionality.

Like @hudsonmd said, adding the following serializer is important:

val cluster = Cluster.build()
    .addContactPoint("localhost") // with ssh tunnel to Neptune
    .port(8182)
    .serializer(new GryoMessageSerializerV3d0())
    .create()

  implicit val g = EmptyGraph.instance.asScala().configure(_.withRemote(DriverRemoteConnection.using(cluster)))

And then for retrieving an item map with properties:

val userMap = g.V().has[Int](UserLabel, userIdKey, id)
        .valueMap()
        .head()

Calling the valueMap before head is important if you want properties - also calling head seems to stop a traversal, so something like .head().out() I don’t think works.

Updates for properties in neptune seem to only work if you first delete the property. I was running into this gnarly bug where if you try to increase the property value of a Double it works, but if you try to decrease it it does not.

g.V().has(UserLabel, userIdKey, uId).properties(userPropertyKey.name).drop().iterate()
g.V().has(UserLabel, userIdKey, uId).property(userPropertyKey, myPropertyValue).iterate()