Gradle Kotlin Buildscripts

Gradle has started supporting kotlin for its build scripts
This presentation describes the pros and cons and helps to drive towards writing kotlin DSL for Android project.

Please follow code samples in below links
Gradle Kotlin Sample: https://github.com/jayashankar987/Gradle_scripts_kotlin
Gradle Groovy with Kotlin DSL (BuildSrc): https://github.com/jayashankar987/GradleGroovyBuildSrc

Transcript

1. Gradle using kotlin scripts Jayashankar
2. We are Hiring
3. Gradle Open-source build automation tool Implemented in Java Runs on JVM
4. Supports Multiple Ecosystems • Java, Kotlin, Scala etc • C, C++, Swift • Android • Python, Go etc
5. How gradle works Build scripts Configuration of tasks Execution of tasks Gradle Engine: resolves dependencies, work avoidance
6. Plugins Reusable and configurable tasks Configurable gradle extensions Contribute: Core Plugins: Java, maven-publish etc.. Community Plugins: Android, kotlin, golang etc.. Models to configure in build scripts using DSL
7. Android Library plugins { id("com.android.application") id("kotlin-android") id("kotlin-kapt") id("kotlin-android-extensions") } android { compileSdkVersion(28) defaultConfig { applicationId = "com.jay.launcherdemo" minSdkVersion(25) targetSdkVersion(28) versionCode = 1 versionName = "1.0" testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" }
8. Beginning of Gradle Help developers for easy declaration of elements How to generate build using tasks Provided extensible DSL Language
9. Problems Tooling difficulty for IDEs (Dinamacity, Metaprogramming) Impact due to missing tool Stuck with no solution Note: other platform/language developers had issues working with groovy
10. Solution Avoid surprise at runtime • More checks at compile time (statically typed) • Avoid trial and error • Performance issue due to dynamism IDE support to understand and write build logic Developer experience • Writing build logic • Identify and fix build issues (Type Safe Logic)
11. Solution
12. Migrating from Groovy Code Examples
13. Benefits • Type safety • Documentation and code navigation • Refactoring • Interoperability
14. Migration Strategies • Go through a step by step process • Doesn’t block team • Prepare your build to migrate easily • Making groovy scripts closer to kotlin • Unify quotes, rewrite properties / functions • Apply gradle fundamentals and best practices (BuildSrc, plugins{}) • Let kotlin logic drive groovy logic
15. Reference Migration Guide https://gradle.org/guides/ Snippets and Best Practices https://docs.gradle.org
16. Key Points in kotlin scripts • Organise build logic • Apply Gradle fundamentals • Use best practices
17. Kotlin DSL Performance • Consumes time only in configuration phase • Build Configuration when nothing has changed can take up to only a second • If not, check for Gradle Performance Guide • Gradle help https://github.com/gradle/gradle/issues/1628 • Performance compared to Groovy DSL
18. Kotlin DSL vs Groovy DSL Kotlin can be slower Script compilation Can be even more for large projects (can be up to a minute more) • During first use (checkout, pulls, switching branches) • Changes in build configurations and buildSrc
19. Gradle Build Cache Script compilation can be cached in Gradle Build Cache org.gradle.caching = true in gradle.properties or --build-cache on command line
20. Improve performance • Parallel Compilation (org.gradle.parallel = true) • Compilation avoidance • Faster kotlin compilations • Optimisations Project with more than one second for build configuration without any change needs to look in for optimizing scripts
21. Thank you