registerOracle.scala

@Callable(i)
func registerAsOracle(dataType: String) = {
    let neededKey = i.callerPublicKey.toBase58String() + "_" + dataType
    let ratingKey = i.callerPublicKey.toBase58String() + "_rating"

    let currentRating = match getInteger(this, ratingKey) {
        case v: Int => v
        case _ => 100
    }
    match (getString(i.caller, neededKey)) {
        case data:String => throw("This oracle is registered already")
        case _ => {
            [
                StringEntry(neededKey, toString(height)),
                IntegerEntry(ratingKey, currentRating)
            ]
        }
    }
}