Android: build.gradle.ktsのすゝめ

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環境

tool	version
Gradle	5.4.1
Kotlin	1.3.41
Android Studio	3.5 Beta 5
Android Gradle Plugin	3.5.0-beta05

既存のプロジェクトへの導入

1. 設定の変更
   ファイル - 設定 - 言語＆フレームワーク - Kotlin - Kotlinスクリプト
   ファイル変更時にスクリプト依存関係を再ロードする にチェックする
   

2. プロジェクトルートに buildSrc を作成
   
   

3. buildSrc に build.gradle.kts と settings.gradle.kts を作成
   

4. build.gradle.kts に記述

5. build.gradle.kts

   plugins {
   `kotlin-dsl`
   }
   repositories {
   jcenter()
   google()
   }
   dependencies {
   implementation("com.android.tools.build:gradle:3.5.0-beta05")
   implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.41")
   }
   

6. Sync now(今すぐ同期)
   

7. プロジェクトルートの settings.gradle を settings.gradle.kts にリネーム
   

8. settings.gradle.kts を編集

settings.gradle.kts

include(":app")
rootProject.name = "My Application"

1. プロジェクトルートの build.gradle を build.gradle.kts にリネーム

2. build.gradle.kts を編集

3. build.gradle.kts

   buildscript {
   repositories {
       google()
       jcenter()        
   }
   dependencies {
       classpath("com.android.tools.build:gradle:3.5.0-beta05")
       classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.41")
   }
   }
   allprojects {
   repositories {
       google()
       jcenter()
   
   }
   }
   task<Delete>("clean") { delete(rootProject.buildDir) }
   

4. app/build.gradle を app/build.gradle.kts にリネーム

5. app/build.gradle.kts を編集

app/build.gradle.kts

plugins {
    id("com.android.application")
    id("kotlin-android")
    id("kotlin-android-extensions")
}
android {
    compileSdkVersion(29)
    buildToolsVersion = "29.0.0"
    defaultConfig {
        applicationId = "com.sorrowblue.myapplication"
        minSdkVersion(23)
        targetSdkVersion(29)
        versionCode =1
        versionName ="1.0"
        testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        getByName("release") {
            isMinifyEnabled = false
            proguardFiles(getDefaultProguardFile("proguard-android-optimize.txt"), "proguard-rules.pro")
        }
    }
}
dependencies {
    implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.3.41")
    implementation("androidx.appcompat:appcompat:1.0.2")
    implementation("androidx.core:core-ktx:1.0.2")
    implementation("androidx.constraintlayout:constraintlayout:1.1.3")
    testImplementation("junit:junit:4.12")
    androidTestImplementation("androidx.test.ext:junit:1.1.0")
    androidTestImplementation("androidx.test.espresso:espresso-core:3.1.1")
}

1. Sync now(今すぐ同期)

スマートに書く

getByName("release") このあたりを拡張関数で記述する

1. buildSrc/src/main/kotlin/Project.kt を作成

buildSrc/src/main/kotlin/Project.kt

import com.android.build.gradle.internal.dsl.BuildType
import org.gradle.api.NamedDomainObjectContainer
fun NamedDomainObjectContainer<BuildType>.release(body: BuildType.() -> Unit) {
    getByName("release") { body(this) }
}

app/build.gradle.kts

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

変数を定義

もちろん変数も定義して使える

1. buildSrc/src/main/kotlin/Versions.kt を作成
2. buildSrc/src/main/kotlin/Versions.kt

   object Versions {
   const val kotlin = "1.3.41"
   const val appcompat = "1.0.2"
   const val `core-ktx` = "1.0.2"
   const val constraintlayout = "1.1.3"
   const val junit = "4.12"
   const val androidx_junit = "1.1.0"
   const val `espresso-core` = "3.1.1"
   }
   

3. buildSrc/src/main/kotlin/Deps.kt を作成

4. buildSrc/src/main/kotlin/Deps.kt

   object Deps {
   const val `kotlin-stdlib-jdk7` = "org.jetbrains.kotlin:kotlin-stdlib-jdk7:${Versions.kotlin}"
   const val appcompat = "androidx.appcompat:appcompat:${Versions.appcompat}"
   const val `core-ktx` = ("androidx.core:core-ktx:${Versions.`core-ktx`}")
   const val constraintlayout = "androidx.constraintlayout:constraintlayout:${Versions.constraintlayout}"
   const val junit = "junit:junit:${Versions.junit}"
   const val androidx_junit = "androidx.test.ext:junit:${Versions.androidx_junit}"
   const val `espresso-core` = "androidx.test.espresso:espresso-core:${Versions.`espresso-core`}"
   }
   

   app/build.gradle.kts

   dependencies {
   implementation(Deps.`kotlin-stdlib-jdk7`)
   implementation(Deps.appcompat)
   implementation(Deps.`core-ktx`)
   implementation(Deps.constraintlayout)
   testImplementation(Deps.junit)
   androidTestImplementation(Deps.androidx_junit)
   androidTestImplementation(Deps.`espresso-core`)
   }
   

Tips

各モジュールの minSdkVersion targetSdkVersion などをまとめる

Project.kt

build.gradle.kts

fun Project.module(action: LibraryExtension.() -> Unit) {
    afterEvaluate {
        if (hasProperty("android") && project.name != "app") {
            action(extensions.getByName("android") as LibraryExtension)
        }
    }
}

build.gradle.kts

build.gradle.kts

subprojects {
    module {
        compileSdkVersion(COMPILE_SDK_VERSION)
        defaultConfig {
            minSdkVersion(MIN_SDK_VERSION)
            targetSdkVersion(TARGET_SDK_VERSION)
            consumerProguardFiles(`consumer-rules`)
            testInstrumentationRunner = ANDROID_JUNIT_RUNNER
        }
    }
}

任意の箇所でapplyしたいとき

app/build.gradle.kts

app/build.gradle.kts

plugins {
    id("com.google.gms.google-services") apply false
}
/*..........processing..........*/
apply(plugin = "com.google.gms.google-services")

プラグインを共通化したい

build.gradle.kts

build.gradle.kts

subprojects {
    if (project.name == "app") {
        apply(plugin = "com.android.application")
    } else {
        apply(plugin = "com.android.library")
    }
    apply(plugin = "kotlin-android")
    apply(plugin = "kotlin-android-extensions")
}