How to create a "base" gradle file in Kotlin DSL for multi-module project?

Question

To reuse code in gradle files I usually have a "base" gradle file for certain modules and just apply them and add whatever new dependencies it might need. I'm in the progress of converting all my gradle files to the new Kotlin DSL but I get "Unresolved reference" errors for keywords using the following "base" file.

plugins {
    id("com.android.library")
    kotlin("kotlin.android")
    kotlin("kapt")
}

android {
    compileSdkVersion(App.compileSdk)
    defaultConfig {
        minSdkVersion(App.minSdk)
        targetSdkVersion(App.targetSdk)
        versionCode = App.versionCode
        versionName = App.versionName
        testInstrumentationRunner = "android.support.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        getByName("release") {
            isMinifyEnabled = false
            proguardFiles(getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro")
        }
    }

    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_1_8
        targetCompatibility = JavaVersion.VERSION_1_8
    }
}

dependencies {
    val implementation by configurations
    val testImplementation by configurations
    val androidTestImplementation by configurations

    implementation(fileTree(mapOf("dir" to "libs", "include" to listOf("*.jar"))))
    implementation(Libs.kotlin_stdlib_jdk8)
    implementation(Libs.appcompat_v7)
    testImplementation(Libs.junit)
    androidTestImplementation(Libs.com_android_support_test_runner)
    androidTestImplementation(Libs.espresso_core)
}

The above file is in my root project and I just use the following in the feature modules

apply(rootProject.file("base-android.gradle.kts"))

This worked fine in Groovy but breaks completely when moving to Kotlin, any ideas on what I'm doing wrong or how to properly have a "base" gradle file in the Kotlin DSL?

EDIT: Adding full error message

Script compilation errors:

  Line 10: android {
           ^ Unresolved reference: android

  Line 11:     compileSdkVersion(28)
               ^ Unresolved reference: compileSdkVersion

  Line 12:     defaultConfig {
               ^ Unresolved reference: defaultConfig

  Line 13:         minSdkVersion(21)
                   ^ Unresolved reference: minSdkVersion

  Line 14:         targetSdkVersion(28)
                   ^ Unresolved reference: targetSdkVersion

  Line 15:         versionCode = 1
                   ^ Unresolved reference: versionCode

  Line 16:         versionName = "1.0"
                   ^ Unresolved reference: versionName

  Line 17:         testInstrumentationRunner = "android.support.test.runner.AndroidJUnitRunner"
                   ^ Unresolved reference: testInstrumentationRunner

  Line 20:     buildTypes {
               ^ Unresolved reference: buildTypes

  Line 21:         getByName("release") {
                   ^ Unresolved reference. None of the following candidates is applicable because of receiver type mismatch: 
                       public inline fun <reified T : Any> NamedDomainObjectCollection<out Any>.getByName(name: String): TypeVariable(T) defined in org.gradle.kotlin.dsl
                       public inline fun <reified T : Any> NamedDomainObjectCollection<out Any>.getByName(name: String, configure: TypeVariable(T).() -> Unit): TypeVariable(T) defined in org.gradle.kotlin.dsl
                       public fun <T : Any> NamedDomainObjectCollection<out Any>.getByName(name: String, type: KClass<TypeVariable(T)>): TypeVariable(T) defined in org.gradle.kotlin.dsl
                       public fun <T : Any> NamedDomainObjectCollection<out Any>.getByName(name: String, type: KClass<TypeVariable(T)>, configure: TypeVariable(T).() -> Unit): TypeVariable(T) defined in org.gradle.kotlin.dsl
                       public inline fun <reified T : Any> ExtensionContainer.getByName(name: String): TypeVariable(T) defined in org.gradle.kotlin.dsl

  Line 22:             isMinifyEnabled = false
                       ^ Unresolved reference: isMinifyEnabled

  Line 23:             proguardFiles(getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro")
                       ^ Unresolved reference: proguardFiles

  Line 23:             proguardFiles(getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro")
                                     ^ Unresolved reference: getDefaultProguardFile

  Line 27:     compileOptions {
               ^ Unresolved reference: compileOptions

  Line 28:         sourceCompatibility = JavaVersion.VERSION_1_8
                   ^ Unresolved reference: sourceCompatibility

  Line 29:         targetCompatibility = JavaVersion.VERSION_1_8
                   ^ Unresolved reference: targetCompatibility

16 errors

I'm currently experiencing the same issue. Did you find a solution? — Thomas Vos, Dec 28 '18 at 11:45
Managed to get it working by removing all contents of the `android { ... }` block except the `compileSdkVersion`. Then wait a few seconds and add the contents again. — Thomas Vos, Dec 28 '18 at 13:47
@ThomasVos This worked for you? I haven't solved this yet and just tried your suggestion and I'm still seeing the same errors. — Nicholas Doglio, Jan 12 '19 at 17:27

score 1 · Answer 1 · answered Jul 07 '20 at 05:45

1

Here's how I do it:

build.gradle.kts

apply(from = "${rootProject.projectDir}/common-setup.gradle.kts")

common-setup.gradle.kts

apply {
    fun android(configure: com.android.build.gradle.internal.dsl.BaseAppModuleExtension.() -> Unit): Unit =
            (project as org.gradle.api.plugins.ExtensionAware).extensions.configure("android", configure)

    android {
        //common setup here
    }
}

answered Jul 07 '20 at 05:45

Sir Codesalot

7,045
2
50
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1

Still the same error `Unresolved reference: android`. – Douglas Fornaro Mar 18 '22 at 12:06

score 0 · Answer 2 · answered Dec 04 '18 at 02:32

0

the problem might come from trying to apply the plugins.

plugins {
    id("com.android.library")
    kotlin("kotlin.android")
    kotlin("kapt")
}

apply(rootProject.file("base-android.gradle.kts"))

...

answered Dec 04 '18 at 02:32

Martin Zeitler

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19
155
216

Just tried again by changing the `plugins {}` to an `apply {}` with the proper plugins and I'm still getting the same "Unresolved reference" errors for keywords. – Nicholas Doglio Dec 04 '18 at 02:39
@NicholasDoglio this is not what I've wrote. it should suffice to pull variables into the script; while keywords should be known. the mere problem might rather be, that the `rootProject` is a library project. move that script to module level, or at least into a separate file than `build.gradle`. – Martin Zeitler Dec 04 '18 at 02:47
Sorry if I misunderstood your original comment. Trying it again with the `base-android.gradle.kts` file in a separate file from the root level `build.gradle` does not fix the Unresolved reference errors. – Nicholas Doglio Dec 04 '18 at 02:54

How to create a "base" gradle file in Kotlin DSL for multi-module project?

2 Answers2