Compilation failed while using Kotlin Extension Functions in a library module

[tzutoo]

Hi,
It seems ObjectBox 0.9.13 will cause compilation failed while using Kotlin Extension Functions in a library module.
Please check the attachment (Contains a project created by Android Studio 3.0 canary 8).

1. app (depends on mylibrary and use the functions in Extensions.kt)
2. mylibrary (Extensions.kt)

Thank you.
MyApplication.zip

[greenrobot]

The compiler complains "getTotalLength" not being found, e.g.:

MainActivity.kt: (5, 30): Unresolved reference: getTotalLength

So, how does this relate to ObjectBox?

[tzutoo]

Not sure if this is related to ObjectBox, but if the ObjectBox dependencies and its plugin in both app and mylibrary's gradle files are removed, the compile process will work.

Please check the attachment.
MyApplicationWithoutObjectBox.zip

[greenrobot]

Did you try with Android Studio 2.3.3? This is the version we tested with.

[tzutoo]

Yes. Unfortunately, the result is the same with Android Studio 2.3.3.
Please see the attachments.

P.S. The only differences between them is app and library modules' gradle files. One is with ObjectBox dependencies, and the other is not.

MyApplication2WithObjectBox.zip
MyApplication2WithoutObjectBox.zip

[greenrobot]

We can reproduce this and are investigating...

Additional question: where do you want to put your entities? In the library and/or the app module?

[greenrobot]

I think we narrowed it down. This line in the library build.gradle file seems to cause the error:

apply plugin: 'io.objectbox.android.transform'

@tzutolin Can you confirm?

[tzutoo]

Yes, it seems to be the cause.

Regarding the question about where to put the entities: In both. For example, the root entities in the library module with their children entities in other app modules. And these app modules can share the same database provided by the library module. Although I am not sure if entity inheritance in ObjectBox is supported yet , it would be great to have such a feature.

[greenrobot]

Thanks for confirming.

Entity inheritance is not supported yet. Also, there are limitations where to place entities. As a rule of thumb, they should reside in a single module. You could have multiple modules with entities, but only if they are totally separated (also different DB file).

[tzutoo]

Thank you for the clarification. ObjectBox is a great product. Would love to see entity inheritance support in the future.

[greenrobot]

It seems that only extension functions are affected. At this point, I am not sure what causes the issue. It could be the Android plugin or our transformer. Will have to investigate more. Also, we will try to reach out to Google devs.

Meanwhile, as a workaround, you could place Kotlin extensions in a separate library module.

[greenrobot]

Update: the Android team is investigating this.
https://issuetracker.google.com/issues/64435479

[tzutoo]

Just find that Android team marked it as Won't Fix. Is there any update to this issue?

[greenrobot]

@tzutolin It could be fixed on our side. I think 1.0.1 already fixes it. Can you confirm?

[greenrobot-team]

No response. Closing. -ut