Totally untested, but something like this might work for you:
case class TempReading(node:String, dt:Int, temp:Double)
object JsonTempReading {
def unapply(obj: JObject) : Option[TempReading] {
obj match {
case JObject(List(
JField("node", JString(node)),
JField("dt", JInt(dt)),
JField("temp", JDouble(temp))
)) => Some(TempReading(node, dt, temp))
case _ => None
}
}
}
val obj : JObject = ... get json data...
val reading = JsonTempReading.unapply(obj)
On Sat, Oct 3, 2009 at 10:13 AM, Kevin Wright
<[email protected]> wrote:
> Sounds to me like you want to create yourself a small helper function
> that can map that structure into your own case class, something like:
>
> case class TempReading(node:String, dt:Int, temp:Double)
>
>
> It should be possible to do this as a layer on top of the json parser.
> So you can go from:
>
> Object(
> List(
> JField(node,JString(00:1D:C9:00:04:9F)),
> JField(dt,JInt(1254553581405)),
> JField(temp,JDouble(27.5))
> )
> )
>
>
> to:
>
> TempReading("00:1D:C9:00:04:9F", 1254553581405, 27.5)
>
> A Map would be an improvement over the raw json, but still is nowhere
> near as concise or type-safe as the dedicated structure.
>
> You probably also want to rethink using ints for datetime (I guess
> this is what dt represents). Take a look at the scala-time library,
> which is a nice wrapper over Java's joda-time.
>
>
>
>
> On Sat, Oct 3, 2009 at 9:46 AM, Peter Robinett <[email protected]>
> wrote:
>>
>> I guess this is basically a question for Joni, but I figure I'll throw
>> it out here for everyone to see.
>>
>> Would it be possible to have extract() support Mapper instances in
>> additional to standard case classes?
>>
>> After parsing some JSON I get the following JValue: JObject(List(JField
>> (node,JString(00:1D:C9:00:04:9F)), JField(dt,JInt(1254553581405)),
>> JField(temp,JDouble(27.5)))). I'd like to turn this into a new
>> instance of my Packet model and it'd be awesome if extract could do
>> that.
>>
>> I don't know how hard would it be to add this feature, so I don't know
>> if this is a reasonable request. This would make making JSON API
>> endpoints really easy for me and I hope for other people too.
>>
>> Peter Robinett
>> >>
>>
>
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