I’ve been toying with Kotlin for a while. Yesterday RC was released, making it one step closer to have a stable version.
One small change that has made me scratch my head a little, even if I read the solution, has been the changes regarding Kotlin Extensions. This had been integrated with the main Kotlin plugin (instead of being a separated plugin) but on RC you need to change your Gradle file a little to keep using it.
The symptom is that you find an “Unresolved reference: kotlinx” plus others that come from the same namespace. Resolution is easy: in the announcement for the release Kotlin 1.0 Release Candidate is Out! in the section Tooling, it reads (bold is mine):
To enable Android Extensions in Gradle in a more idiomatic way, we now say:
apply plugin: 'kotlin-android-extensions'
build.gradle file (individually for each project).
The old way doesn’t work any more and prints fixing instructions to the output.
So, I haven’t found this instructions, but the solution is easy: apply the new kotlin-android-extensions plugin right after the kotlin-android plugin in your gradle file. Usually, the end result will be like this:
apply plugin: 'com.android.application' apply plugin: 'kotlin-android' apply plugin: 'kotlin-android-extensions'
After that you just need to sync your Gradle configuration and rebuild the whole project.