Rename a json property…

[Viktor Hedefalk]

Hi,

I'm sorry to repost. Tried to use the irc channel, but newbie me shut it down and I have no idea if there's already an answer there. Can't seem to find a way to check history. I'm not only argonaut newb, but irc newb too :)

Here's the question again:

Hi,  First I wanna say thanks! I’ve been using Argonaut with codecs to and from scala objects and really love the API. Currently I have this use case where I go directly from Mongo to Argonaut and then I need to move things around just a tiny bit before outputting json to a web client. So I’m trying to understand the cursor api.

My first issue is trying to rename an ”_id” field to just ”id”. I figured I could delete and add but can’t get my head around it. To get the value it seems I need to drill down with something like id.withFocus(_.withString(theIdValue => ???)) but I can only keep the value inside that function which needs to return a new value.

Almost felt tempted to use a ”var” for the first time ever :) Hehe, not really, but I really feel thick as a brick here. Any pointers highly appreciated!

Cheers,

Viktor

[seantparsons]

I would suggest leaving the cursor API to one side, you're better off using methods on the Json type to manipulate the structure like withObject.

Sean.

[Viktor Hedefalk]

Thanks Sean!

Yeah, I found http://stackoverflow.com/a/21267006/312873 and ended up with something as simple as:

def renameField(before: JsonField, after: JsonField)(obj: JsonObject) =
obj(before).map(v => (obj - before) + (after, v)).getOrElse(obj)

val updated = json.withObject(renameField("_id", "id"))

Cheers,

Viktor