具有隐式json格式的Scala ActiveRecord

Question

I have a scala-activerecord:

case class Person(name: String) extends ActiveRecord with Timestamps
object Person extends ActiveRecordCompanion[Person]

Everything works ok.

Suddenly, I want to provide an API and repond with json representation of the entity, so I modified the code:

case class Person(name: String) extends ActiveRecord with Timestamps
object Person extends ActiveRecordCompanion[Person] with DefaultJsonProtocol {
  implicit val jsonFormat = jsonFormat1(Request)
}

Now it causes an exception:

com.github.aselab.activerecord.SchemaSettingException: Cannot find table definition of class Person
  at com.github.aselab.activerecord.ActiveRecordException$.tableNotFound(ActiveRecordException.scala:48)
  at com.github.aselab.activerecord.Config$$anonfun$schema$1.apply(ActiveRecordConfig.scala:29)
  at com.github.aselab.activerecord.Config$$anonfun$schema$1.apply(ActiveRecordConfig.scala:29)
  at scala.collection.MapLike$class.getOrElse(MapLike.scala:128)
  at scala.collection.AbstractMap.getOrElse(Map.scala:59)
  at com.github.aselab.activerecord.Config$.schema(ActiveRecordConfig.scala:29)
  at com.github.aselab.activerecord.ActiveRecordBaseCompanion$class.schema(ActiveRecord.scala:116)
  at Person$.schema$lzycompute(Request.scala:12)
  at Person$.schema(Request.scala:12)
  at com.github.aselab.activerecord.ActiveRecordBaseCompanion$class.table(ActiveRecord.scala:123)
  at Person$.table$lzycompute(Request.scala:12)
  at Person$.table(Request.scala:12)
  at com.github.aselab.activerecord.ActiveRecordBaseCompanion$class.all(ActiveRecord.scala:133)
  at Person$.all(Request.scala:12)
  at com.github.aselab.activerecord.inner.CompanionIterable$class.companionToIterable(Implicits.scala:15)
  at Person$.companionToIterable(Request.scala:12)
  at Person$.<init>(Request.scala:13)
  at Person$.<clinit>(Request.scala)
  ... 34 more

EDIT: I put two breakpoints in ActiveRecordConfig.scala :

Breakpoint A here:

def schema(companion: ActiveRecordBaseCompanion[_, _]): ActiveRecordTables = {
  val clazz = companion.classInfo.clazz
  tables.getOrElse(clazz, throw ActiveRecordException.tableNotFound(clazz.toString))
}

Breakpoint B here:

def registerSchema(s: ActiveRecordTables) = {
  conf = s.config
  s.all.foreach(t => _tables.update(t.posoMetaData.clasz, s))
}

With the first code (without json implicit) the execution hits the breakpoint B.

With the second code (including json implicit) the execution hits the breakpoint A first, causing the exception.

Answer 1

Json support work in the version 0.3.1 of scala-activerecord , see wiki and this issue . As for now, with the latest version 0.3.0 you can use the first code and the form values deserialization:

case class Person(name: String) extends ActiveRecord with Timestamps
object Person extends ActiveRecordCompanion[Person]

And in your eg spray controller:

import spray.httpx.SprayJsonSupport._
import spray.json.DefaultJsonProtocol._

requestContext.complete(Person.find(id).toFormValues)

The method toFormValues will return Map[String, String] , which can be by spray-json implicitly converted to json.