readAllRelationshipsOfNode – can I specify the type of relationship?

[deemeetree]

Is it possible to specify the type of relationships that need to be queried using db.readAllRelationshipsOfNode or do I need to use db.cypherQuery for that?

Thank you!

[freeeve]

I looked briefly but couldn't find an implementation for that particular request (http://docs.neo4j.org/chunked/milestone/rest-api-relationships.html#rest-api-get-typed-relationships)

Shouldn't be too hard to add, though... very similar to the existing ones, with an added type.

[philippkueng]

Thanks @wfreeman, you're fast. Seems indeed to be fairly trivial. @deemeetree could you create a PR? otherwise i can make that change too, but on friday the earliest.

[deemeetree]

@wfreeman @philippkueng Thank you for the fast response! I'll look in the code and it will be great if we can also add the same functionality for reading directed relationships as well, such as readIncomingRelationshipsOfNode and readOutgoingRelationshipsOfNode

[freeeve]

Yeah, similar. What do you guys think the names should be? readIncomingTypedRelationshipsOfNode? readTypedIncomingRelationshipsOfNode?

Probably should be refactored to reuse the same function at this point, since there's a lot of repetition between the different versions.

[deemeetree]

I think readIncomingTypedRelationshipsOfNode following the convention there already is and it's more readable like that. But also why not just add a second optional parameter, which would specify the type to avoid creating too many functions? Probably also could be good if several types could be listed at once, but I don't know how difficult that.

[philippkueng]

Hi @deemeetree and @wfreeman,

Thanks for your input and thinking. Also sorry for the late response. I think going with an optional parameter might be the smartest move here in order not to create more code bloat and also keep the amount of different functions fairly small.

Thinking about a function definition like this Neo4j.prototype.readAllRelationshipsOfNode = function(node_id, [options], callback){}

With options having the form:

{
  'types': ['type1', 'type2', ...]
}

Would that be ok for you both? It has the added benefit that other options could be added easily and it doesn't break existing implementations.

[freeeve]

I don't think the name readAll... makes sense when you're only reading part of them! :) Maybe just readRelationshipsOfNode? or even more concise: getRels()?... although it doesn't match the rest of the API.

[philippkueng]

Good point, thank you. Keeping the function readAll... for legacy and introducing readRelationshipsOfNode. Think getRels on the other hand might promise too much in one function.

[freeeve]

sounds good.

[philippkueng]

Hi @wfreeman and @deemeetree,

Ok, the tagged relationships are implemented, documented (https://github.com/philippkueng/node-neo4j#advanced-relationship-operations) and released in 2.0.0-RC5. Let me know if you're missing anything else.

Best, Philipp