Can I create a generic type in a kotlin data class?

Question

I have a backend that will always return either a "success" with some data, as in the json field field will be named success and have the data in it. Or it will return an error object in a json format. So I'd like to have some sort of BaseResponse, so when I use it I could do something like BaseResponse so the success will be mapped as a Person object.

So I was thinking of doing like this:

@Parcelize
data class BaseResponse<T>(
     val success: T? = null
) : Parcelable

But it says Type is not directly supported with Parcelize. Is there any way I can do this at all? Or do I need to write something custom? The calls etc are called using Retrofit and Gson as serializer.

Does this answer your question? [Is it possible to parcel a generic class?](https://stackoverflow.com/questions/18797399/is-it-possible-to-parcel-a-generic-class) — matt freake, Mar 02 '20 at 09:24
It doesn't seem to take into account that it's data classes I need. — Mikkel Larsen, Mar 02 '20 at 09:35

92AlanC · Accepted Answer · 2020-11-03T00:27:41.497

11

You can do so by requiring T to be an implementation of Parcelable, like this:

@Parcelize
data class BaseResponse<T: Parcelable>(val success: T? = null) : Parcelable

edited Nov 03 '20 at 00:27

answered Mar 02 '20 at 09:50

92AlanC

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This does not compile with the error "non-static type variable T cannot be referenced from a static context" – Zakhar Rodionov Dec 18 '20 at 15:03
this solution is not working for me. Throws an error "non-static type variable T cannot be referenced from a static context". is there anything else? – Jaspal May 15 '21 at 10:48

Can I create a generic type in a kotlin data class?

1 Answers1