Is there a way to add an annotation to a class def...

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[Shan]

Is there a way to add an annotation to a class defined in a separate library? Some kind of extension annotation? E.g. I have a class called data class Foo() in my network library, but I would like to add an annotation to it in my Android app module for use with my database.

[groostav]

I dont think this is within kotlin's power, this would need changes in the jvm-spec. You can probably get away with classpath games though, compile with the annotation and omit the jar containing it as a runtime dep.

[bezrukov]

If you are about room - there are few things you can do:
1. Use room-common dep in your network lib (it can be pure java lib). Then just add this dataclass to your DB
2. Use @Embedded for entity declaration - you can just write data class FooEntity(@Embedded val foo: Foo) only for schema generation, then you will be able to use Foo in all adapters (one note though - you will need to add targetEntity for @Insert)

[Shan]

Never thought of that second option. That should work nicely. Thank you! Was really tired of declaring my data classes twice.

[Shan]

Will that work if the data class I am `@Embedded`ing also has nested data classes?

[Shan]

I don't think it will, alas.. I will try the first option I suppose

[bezrukov]

It depends on how are you planning to store these nested data classes - if in a single column, you can use type adapter for these classes