How to store child objects on GAE using JDO from Scala
- by Gero
Hi,
I'm have a parent-child relation between 2 classes, but the child objects are never stored. I do get an warning:
"org.datanucleus.store.appengine.MetaDataValidator checkForIllegalChildField: Unable to validate relation net.vermaas.kivanotify.model.UserCriteria.internalCriteria"
but it is unclear to me why this occurs. Already tried several alternatives without luck.
The parent class is "UserCriteria" which has a List of "Criteria" as children.
The classes are defined as follows (Scala):
class UserCriteria(tu: String, crit: Map[String, String]) extends LogHelper {
@PrimaryKey
@Persistent{val valueStrategy = IdGeneratorStrategy.IDENTITY}
var id = KeyFactory.createKey("UserCriteria", System.nanoTime)
@Persistent
var twitterUser = tu
@Persistent
var internalCriteria: java.util.List[Criteria] = flatten(crit)
def flatten(crits: Map[String, String]) : java.util.List[Criteria] = {
val list = new java.util.ArrayList[Criteria]
for (key <- crits.keySet) {
list.add(new Criteria(this, key, crits(key)))
}
list
}
def criteria: Map[String, String] = {
val crits = mutable.Map.empty[String, String]
for (i <- 0 to internalCriteria.size-1) {
crits(internalCriteria.get(i).name) = internalCriteria.get(i).value
}
Map.empty ++ crits
}
// Stripped the equals, canEquals, hashCode, toString code to keep the code snippet short...
}
@PersistenceCapable
@EmbeddedOnly
class Criteria(uc: UserCriteria, nm: String, vl: String) {
@Persistent
var userCriteria = uc
@Persistent
var name = nm
@Persistent
var value = vl
override def toString = {
"Criteria name: " + name + " value: " + value
}
}
Any ideas why the childs are not stored? Or why I get the error message?
Thanks,
Gero
