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#serialization
Title
# serialization
s

Stylianos Gakis

07/12/2022, 1:01 PM
I got an interface 
Action
with normal subclass 
class SomeAction : Action
and another interface subclass of type 
interface ServerAction : Action
which itself has implementations like 
class SpecificServerAction : ServerAction
. I’ve been trying to think of how I need to setup my SerializersModule to make all of this work. From what I understand since my interface is not sealed, I need to do something like this
Copy code
polymorphic(Action::class) {
    subclass(ServerAction::class, //??)
    subclass(NavigationPushAction::class, NavigationPushAction.serializer())
    subclass(NavigationPopAction::class, NavigationPopAction.serializer())
    subclass(VoidAction::class, VoidAction.serializer())
}
but how do I do this for the ServerAction? Optimally I’d like to be able to define my ServerAction hierarchy the same way by providing all the subclasses, but I don’t see a way that the dsl allows me to do this? I could probably do this by creating my own 
object ServerActionSerializer : KSerializer<ServerAction> {
and implementing it, but I’d rather not if possible? I like this subclass approach which can take care of it for me. Am I missing something, any ideas maybe? Some part of the api I can be using that I am not?
e

Emil Kantis

07/12/2022, 1:38 PM
Are you using the latest version of kotlinx-serialization? I can do 
polymorphic(Action::class,  SpecificServerAction::class, SpecificServerAction.serializer())
s

Stylianos Gakis

07/12/2022, 2:28 PM
That would mean I’d then register a bunch of 
polymorphic
calls if I have many implementations of 
ServerAction
(which I do) Something like this:
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polymorphic(Action::class) {
    subclass(NavigationPushAction::class, NavigationPushAction.serializer())
    subclass(NavigationPopAction::class, NavigationPopAction.serializer())
    subclass(VoidAction::class, VoidAction.serializer())
}
polymorphic(Action::class, SpecificServerAction::class, SpecificServerAction.serializer())
polymorphic(Action::class, Specific2ServerAction::class, Specific2ServerAction.serializer())
polymorphic(Action::class, Specific3ServerAction::class, Specific3ServerAction.serializer())
... and so on
And at no point in this structure am I referencing 
ServerAction
itself. I would’ve expected I’d need to also add something like
Copy code
polymorphic(ServerAction::class) {
    subclass(SpecificServerAction::class, SpecificServerAction.serializer())
}
And then somehow tell 
polymorphic(Action::class)
about it, since 
ServerAction
is also a subclass of 
Action
. But that’s not possible I suppose. In my mind that’s what would have made the most sense 😄 Tell Action about all of its subclasses. Tell ServerAction about all of its subclasses as well. And then inform Action that ServerAction is one of them too.
e

ephemient

07/12/2022, 5:29 PM
Copy code
polymorphic(Action::class) {
    subclass(SpecificServerAction::class, SpecificServerAction.serializer())
}
polymorphic(ServerAction::class) {
    subclass(SpecificServerAction::class, SpecificServerAction.serializer())
}
s

Stylianos Gakis

07/12/2022, 5:42 PM
Aha so I have to duplicate the subclasses since they're technically both implementations of Action and of ServerAction at the same time. What's with the different syntax between the two, why specify the serializer in one but not the other? Is it just because I can skip it, or is it that I must skip it? If it's just a can, I'd rather keep it consistently the same 😅
e

ephemient

07/12/2022, 5:44 PM
ah, failure to copy-paste. there is a reified helper so you shorten the call arguments, but it's not "must"
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