How do I exclude a property in a data class from b...

# android

[haroldadmin]

How do I exclude a property in a data class from being Parcelized?

@Parcelize
data class State(
  val userId: String = 1234,
  val userResource: Resource<User> = Resource.Uninitialized
): Parcelable

I want to exclude the userResource property from being Parcelized, as the Resource class is not Parcelable.

Here is the warning I get from the IDE: Type is not directly supported by @Parcelize. Annotate the field with @RawValue if you want to be serialized using 'writeValue()'

@Transient does not work, and neither does @IgnoreOnParcel (I get the warning that it is not applicable on properties in primary constructor). Any way to solve this?

[nglauber]

Have you tried remove this property from the primary constructor?

[haroldadmin]

That works, but it requires me to create a secondary constructor. All the parcelable properties go in the primary constructor, and the un-parcelable ones go in the secondary constructor.

However this involves a dealbreaker: we can not have `val`s in secondary constructors. So the only solution is to do something like this:

@Parcelize
data class State(
  val userId: Int = 1234
): Parcelable {
  private lateinit var resource: Resource<User>
  constructor(missionId: Int, userRes: Resource<User>) {
    this.resource = userRes
  }
}

This, of course is not great because I lose immutability (resource is now a var). Also, the auto-generated copy function does not accept secondary constructor params.

[nglauber]

yeah… you’re right… 😞
maybe you can wrap your class and just serialize the internal props that you want… 🤷‍♂️

[rkeazor]

a simple way would just the factor pattern

[rkeazor]

factory pattery

[rkeazor]

or the secondary constructor ,would just call the primary constructor. or don't use the @Parcerlize annotation , and just override everything manually