i2b2-merge-to…

JsonEnrichments.scala
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			package net.shrine.protocol.query

			import net.liftweb.json.JsonAST._
			import scala.util.Try
			import scala.util.Success
			import scala.util.Failure

			/**
			* @author clint
			* @date Jul 24, 2014
			*/
			object JsonEnrichments {
			implicit final class HasWithChild(val json: JValue) extends AnyVal {
			def withChildString(childName: String): Try[String] = withChild(childName, JString.unapply(_))

			def withChild[J <: JValue : Manifest, T](childName: String, extractor: J => Try[T])(implicit discriminator: Int = 42): Try[T] = {
			withChild(childName, (j: J) => extractor(j).toOption)
			}

			def withChild[J <: JValue : Manifest, T](childName: String, extractor: J => Option[T]): Try[T] = {
			def isAJ(j: J): Boolean = manifest[J].runtimeClass.isAssignableFrom(j.getClass)

			json match {
			case null => Failure(new Exception("Null JSON value passed in"))
			case _ => json.children.collect {
			case JField(name, value: J) if isAJ(value) && name == childName => extractor(value)
			}.flatten.headOption.map(Success(_)).getOrElse {
			val children = json.children.collect { case JField(name, _) => s"'$name'" }.mkString(",")

			Failure(new Exception(s"Couldn't find child with name '$childName' in '$json'; children are $children"))
			}
			}
			}
			}
			}