Please update the Datastore with Protobuf codelab to support Gradle Kotlin DSL / Kotlin code generation

[danielesegato]

Hi,

It took me some hours to figure out how to set it up correctly, I think the codelab should mention it:

import com.google.protobuf.gradle.id

plugins {
  // ...
  id("com.google.protobuf") // version 0.9.1
}

protobuf {
    protoc {
        artifact = "com.google.protobuf:protoc:3.21.9"
    }

    // Generates the java Protobuf-lite code for the Protobufs in this project. See
    // https://github.com/google/protobuf-gradle-plugin#customizing-protobuf-compilation
    // for more information.
    generateProtoTasks {
        // see https://github.com/google/protobuf-gradle-plugin/issues/518
        // see https://github.com/google/protobuf-gradle-plugin/issues/491
        
        // all() here because of android multi-variant
        all().forEach { task ->
            // this only works on version 3.8+ that has buildins for javalite / kotlin lite
            // with previous version the java build in is to be removed and a new plugin
            // need to be declared
            task.builtins {
                id("java") { // id is imported above
                    option("lite")
                }
                id("kotlin") {
                    option("lite")
                }
            }
        }
    }
}

depencencies {
  // ...
  implementaiton("com.google.protobuf:protobuf-javalite:3.21.9")
  implementaiton("com.google.protobuf:protobuf-kotlin-lite:3.21.9")
  // ....
}

this generate kotlin helpers for the proto and correctly works on gradle kotlin-dsl

the codelab only show how to configure for java and gradle groovy

[mariobat88]

I was struggling with that for so long. Thank you @danielesegato

[kanetik]

@danielesegato Wish I'd found this about 3 days ago! I finally got it to build the Kotlin DSL after FAR too much trial and error. However, what's weird now is that when I try to write a pref like so: userData { thingDateTime = timestamp } it doesn't seem to actually save the value. Do you happen to have working examples using the DSL? I'd love to see how you did it, if so.