Parcelize and ObjectBox clash - kotlin

Question

I'm using kotlin and ObjectBox in my application. My object box entity looks something like
#Entity
class Order {
#Id var id: Long = 0
lateinit var customer: ToOne<Customer>
}
#Entity
class Customer {
#Id var id: Long = 0
#Backlink
lateinit var orders: List<Order>
}
But when I use #Parcelize, the properties are being ignored in the parcel. How do I use #Parcelize but still include these properties? I tried overriding writeToParcel but I am not allowed to override it due to #Parcelize.

Answer 1

According to docs, you have to declare all properties in primary constructor, which should be serialized via #Parcelize. All other ones are ignored.
ObjectBox doesn't support ToOne so you have to write custom Parceler. In the end your solution should look like this:
#Entity
#Parcelize
#TypeParceler<ToOne<Customer>, ToOneCustomerParceler>
class Order(
#Id var id: Long = 0,
var customer: ToOne<Customer>
) : Parcelable
#Entity
#Parcelize
class Customer(
#Id var id: Long = 0,
#Backlink var orders: List<Order>
) : Parcelable
object ToOneCustomerParceler : Parceler<ToOne<Customer>> {
override fun create(parcel: Parcel): ToOne<Customer> {
//Somehow recreate ToOne instance
...
}
override fun ToOne<Customer>.write(parcel: Parcel, flags: Int) {
val customer = target
...
}
}
Also don't forget to include correct dependencies:
dependencies {
compile "io.objectbox:objectbox-android:$objectboxVersion"
compile "io.objectbox:objectbox-kotlin:$objectboxVersion"
}
P.S. Use different models for each purpose (#Entity and #Parcelize) even if both are the same. It is much easier to manage them since you separate your intentions into 2 models, rather than trying to push everything into single one.