How To Access Variant.outputfilename In Kotlin

We've been using a snippet like this one to rename the APK file generated by our Gradle build: android.applicationVariants.all { variant -> variant.outputs.all { out

Solution 1:

A little simplified version of @david.mihola answer:

android {

    /**
    * Notes Impl: Use DomainObjectCollection#all
    */
    applicationVariants.all {
        val variant = this
        variant.outputs
            .map { it as com.android.build.gradle.internal.api.BaseVariantOutputImpl }
            .forEach { output ->
                val outputFileName = "YourAppName - ${variant.baseName} - ${variant.versionName}${variant.versionCode}.apk"
                println("OutputFileName: $outputFileName")
                output.outputFileName = outputFileName
            }
    }

}

Solution 2:

Browsing through the source code of the Android Gradle plugin, I think I found the answer - here we go:

We are actually dealing with objects of type BaseVariantOutputImpl and this class does have both these methods:

publicStringgetOutputFileName() {
    return apkData.getOutputFileName();
}

publicvoidsetOutputFileName(String outputFileName) {
    if (newFile(outputFileName).isAbsolute()) {
        thrownewGradleException("Absolute path are not supported when setting " +
                    "an output file name");
    }
    apkData.setOutputFileName(outputFileName);
}

Using this knowledge we can now:

import com.android.build.gradle.internal.api.BaseVariantOutputImpl

and then cast our target objects like so:

applicationVariants.all(object : Action<ApplicationVariant> {
    overridefunexecute(variant: ApplicationVariant) {
        println("variant: ${variant}")
        variant.outputs.all(object : Action<BaseVariantOutput> {
            overridefunexecute(output: BaseVariantOutput) {

                val outputImpl = output as BaseVariantOutputImpl
                val fileName = output.outputFileName
                        .replace("-release", "-release-v${defaultConfig.versionName}-vc${defaultConfig.versionCode}-$gitHash")
                        .replace("-debug", "-debug-v${defaultConfig.versionName}-vc${defaultConfig.versionCode}-$gitHash")
                println("output file name: ${fileName}")
                outputImpl.outputFileName = fileName
            }
        })
    }
})

So, I guess: Yes, there is some Groovy magic at work, namely that Groovy's dynamic type system allows you to just access getOutputFileName and setOutputFileName (by way of the abbreviated outputImpl.outputFileName syntax, as in Kotlin) from your code, hoping they will be there at runtime, even if the compile time interfaces that you know about don't have them.

Solution 3:

Shorter version using lambdas:

    applicationVariants.all{
        outputs.all {
            if(name.contains("release"))
                (thisas BaseVariantOutputImpl).outputFileName = "../../apk/$name-$versionName.apk"
        }
    }

This will place APK into app/apk folder with name made of variant name and version code. You can change the format of filename as you wish. Important: it must be done only on release builds, because ".." in path corrupts debug build process with strange errors.