Gradle + Kotlin DSL = ⚡🚀

100% Kotlin codebase for your project? Why not?! Maybe it is time to use only one language for the codebase of our project and for all Gradle scripts. See together news about Gradle 5.0 and Kotlin DSL support production ready!

Find source code of this talk on this GitHub project: https://github.com/GerardPaligot/devfestlille-android

Transcript

1. Gradle + Kotlin DSL = ⚡" @GerardPaligot
2. What is a DSL? Domain Specific Language
3. node(name = "resources") { element(name = "string") { attr(key = "name", value = "example") string(content = "I'm a bugdroid") } element(name = "plurals") { element(name = "string") { attr(key = "name", value = "one") string(content = "I have 1 song") } element(name = "string") { attr(attribute = "name" to "other") string(content = "I have multiple songs") } } }
4. Promises Why should I care about it?
5. Statically typed type-safe DSL
6. IDE experience
7. Interoperability with existing scripts
8. Maximum readability
9. 100% Kotlin
10. Migration Groovy to Kotlin
12. - implementation project(':agenda') + implementation project(":agenda")
13. - classpath("com.android.tools.build:gradle:$versions.androidPlugin") + classpath("com.android.tools.build:gradle:${versions.androidPlugin}")
14. android { defaultConfig { - applicationId "com.paligot.devfestlille" + applicationId = "com.paligot.devfestlille" minSdkVersion versions.minSdk targetSdkVersion versions.targetSdk - versionCode 1 - versionName "1.0" - testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner" + versionCode = 1 + versionName = "1.0" + testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" } }
15. android { defaultConfig { applicationId = "com.paligot.devfestlille" - minSdkVersion versions.minSdk - targetSdkVersion versions.targetSdk + minSdkVersion(versions.minSdk) + targetSdkVersion(versions.targetSdk) versionCode = 1 versionName = "1.0" testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" } }
16. - apply plugin: "com.android.library" - apply plugin: "kotlin-android" - apply plugin: "kotlin-android-extensions" - apply plugin: "kotlin-kapt" - apply plugin: "androidx.navigation.safeargs.kotlin" + plugins { + id("com.android.library") + id("kotlin-android") + id("kotlin-android-extensions") + id("kotlin-kapt") + id("androidx.navigation.safeargs.kotlin") + }
17. include(":app", ":agenda", ":shared") rootProject.name = "DevFestLille" :app :agenda :shared :buildSrc settings.gradle > settings.gradle.kts
18. :app :agenda :shared :buildSrc → build.gradle.kts plugins { `kotlin-dsl` } repositories { jcenter() }
19. :app :agenda :shared object Versions { val library = "1.0" // ... } object Dependencies { val library = "my.package:library:${Versions.library}" // ... } :buildSrc → src/main/kotlin → Dependencies.kt
20. :app :agenda :shared buildscript { repositories { google() jcenter() } dependencies { classpath(Dependencies.androidPlugin) classpath(Dependencies.androidx.navigation.plugin) classpath(Dependencies.kotlin.plugin) } } :buildSrc build.gradle > build.gradle.kts
21. :app :agenda :shared buildscript { // ... } - task clean(type: Delete) { - delete rootProject.buildDir - } + tasks { + val clean by registering(Delete::class) { + delete(buildDir) + } + } :buildSrc build.gradle > build.gradle.kts
22. :agenda → build.gradle.kts :shared → build.gradle.kts plugins { // ... } android { compileSdkVersion(Versions.targetSdk) defaultConfig { minSdkVersion(Versions.minSdk) targetSdkVersion(Versions.targetSdk) versionCode = 1 versionName = "1.0" } buildTypes { // ... } dataBinding { // ... } } :buildSrc :app → build.gradle.kts
23. :agenda → build.gradle.kts :shared → build.gradle.kts plugins { // ... } android { compileSdkVersion(Versions.targetSdk) defaultConfig { // ... } buildTypes { - release { - minifyEnabled = false + named("release") { + isMinifyEnabled = false proguardFiles(getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro") } } dataBinding { // ... } } :buildSrc :app → build.gradle.kts
24. :app → build.gradle.kts :agenda → build.gradle.kts :shared → build.gradle.kts plugins { // ... } android { compileSdkVersion(Versions.targetSdk) defaultConfig { // ... } buildTypes { // ... } dataBinding { - enable = true + isEnabled = true } } :buildSrc
25. Personal Feedback Pros & Cons
26. # 100% Kotlin
27. # 100% Kotlin API incompatible $
28. % IDE experience
29. % IDE experience New module Groovy only &
30. ' Refactoring code
31. ' Refactoring code Autocomplete slow (
32. ) Official documentation
33. ) Official documentation Not many blog posts *
34. So what? Should I migrate to Kotlin?
35. Thank you! @GerardPaligot
36. References • DevFest Android Sample https://github.com/GerardPaligot/devfestlille-android • Gradle Kotlin DSL Primer https://docs.gradle.org/current/userguide/kotlin_dsl.html • Migration blog post https://medium.com/@stoltmanjan/migrating-gradle-to- kotlin-dsl-in-android-studio-3-3-18651f37227f • Migration blog post https://proandroiddev.com/migrating-android-build-scripts- from-groovy-to-kotlin-dsl-f8db79dd6737