Firstly, thanks for your great work on the Spring Data Graph API so far. I took a look at the draft you had out here:
https://gist.github.com/835408 And it looks like an awesome start. I'm relatively new to Neo4J (saw the SpringOne keynote and the roo talk), but one thing I think would be very useful is if there was some sort of higher-level PathMapper that worked at the GraphBacked level, instead of working at the Neo4j node level. In my immediate case, I have three NodeBacked types in my graph: TypeA, TypeB, and TypeC. Types B and C can be related to Type A through the same relationship type, but I want to define two traversals that include only each type respectively. I'm using the FieldTraversalDescriptionBuilder but its falling down when I try to do something like the following: class TypeA { @GraphTraversal(traversalBuilder = RelatedTraversalBuilder.class, elementClass = TypeB.class) private Iterable<TypeB> typeBs; @GraphTraversal(traversalBuilder = RelatedTraversalBuilder.class, elementClass = TypeC.class) private Iterable<TypeC> typeCs; private static class RelatedTraversalBuilder implements FieldTraversalDescriptionBuilder { public TraversalDescription build(NodeBacked start, Field field) { return new TraversalDescriptionImpl().relationships(RelTypes.RELATED_TO); } } } In this particular case, the traversal will return a mix of TypeB and TypeC and throw a class cast exception. I'd love to have some abstraction of a Path such that path.startNode() and path.endNode() would return the actual NodeBacked classes themselves, so I could write my PathMappers to use something like: class MyPathMapper implements PathMapper { public Void mapPath(GraphPath path) { if(path.endNode() instanceof TypeB) { return Evaluator.INCLUDE_AND_PRUNE } else { return Evaluator.EXCLUDE_AND_PRUNE } } } It seems like the template should be able to provide this with something along the lines of: interface PathMapper<T> { ... @Override public Void mapPath(GraphPath graphPath) { eachPath(graphPath); return null; } } interface GraphPath { NodeBacked startNode(); NodeBacked endNode(); ... } The key here is, of course, that GraphPath provides NodeBacked classes instead of primitive neo4j nodes. Beyond the simple instanceof example I gave, I think it would also be useful for evaluating paths using on NodeEntity properties rather than having to call node.getProperty('somePropertyNameThatIWillProbablyMisspell'). Not sure if my request makes sense, or is reasonable to implement, but I think it would certainly make my life a lot easier. -- View this message in context: http://neo4j-user-list.438527.n3.nabble.com/Neo4j-Spring-Neo4jTemplate-tp2525460p2563548.html Sent from the Neo4J User List mailing list archive at Nabble.com. _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
