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Scaling your build logic Antal Monori, Android Engineer @ Wise

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Show your hands If you know this little elephant...

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Disclaimer1 1 This presentation will focus on Gradle as a build tool.

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Definition build logic (n.)

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Definition build logic (n.) A set of declarative instructions and plugins that transform source code and resources into deployable packages.

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Definition build logic (n.) A set of declarative instructions and plugins that transform source code and resources into deployable packages. "Build logic is how the software will be built. It is the code that adds new capabilities, integrates different tools, and supplies conventions to the software definition."2 2 https://blog.gradle.org/declarative-gradle#software-definition-vs-build-logic

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Goals

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Goals 1. Some Gradle fundamentals

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Goals 1. Some Gradle fundamentals 2. How to create a Gradle plugin

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Goals 1. Some Gradle fundamentals 2. How to create a Gradle plugin 3. Pre-compiled scripts vs convention plugins

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Goals 1. Some Gradle fundamentals 2. How to create a Gradle plugin 3. Pre-compiled scripts vs convention plugins 4. buildSrc vs includedBuild()

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Goals 1. Some Gradle fundamentals 2. How to create a Gradle plugin 3. Pre-compiled scripts vs convention plugins 4. buildSrc vs includedBuild() 5. How to build a declarative, custom DSL

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Let's get started // settings.gradle.kts rootProject.name="sample-gradle-project" pluginManagement { repositories { google() mavenCentral() gradlePluginPortal() } } include (":app")

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Let's get started // settings.gradle.kts rootProject.name="sample-gradle-project" pluginManagement { repositories { google() mavenCentral() gradlePluginPortal() } } include (":app")

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Disclaimer3 3 Always consider the stage of the project. Just as to any approach there are always caveats.

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Let's create a more realistic example4 $ projectGenerator --shape triangle --layers 5 --modules 100 --classes-module-type random --classes-module 150 --language kts --agp-version 8.7.2 --kgp-version 2.1.0 --type-of-string-resources large --generate-unit-test true --gradle 8.11.1 --dependency-plugins true 4 https://github.com/cdsap/ProjectGenerator

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Let's create a more realistic example4 $ projectGenerator --shape triangle --layers 5 --modules 100 --classes-module-type random --classes-module 150 --language kts --agp-version 8.7.2 --kgp-version 2.1.0 --type-of-string-resources large --generate-unit-test true --gradle 8.11.1 --dependency-plugins true 4 https://github.com/cdsap/ProjectGenerator

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A more realistic example // settings.gradle.kts rootProject.name="sample-gradle-project" include (":app") include (":layer_0:module_0_1") include (":layer_0:module_0_2") include (":layer_0:module_0_3") include (":layer_0:module_0_4") include (":layer_0:module_0_5") include (":layer_0:module_0_6") include (":layer_0:module_0_7") include (":layer_0:module_0_8") include (":layer_0:module_0_9") include (":layer_0:module_0_10") include (":layer_0:module_0_11") include (":layer_0:module_0_12") include (":layer_0:module_0_13") include (":layer_0:module_0_14") include (":layer_0:module_0_15") include (":layer_0:module_0_16") include (":layer_1:module_1_17") include (":layer_1:module_1_18") include (":layer_1:module_1_19") include (":layer_1:module_1_20") // ...

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With many build scripts plugins { id("com.android.library") id("org.jetbrains.kotlin.android") id("kotlin-kapt") } val normalizedName = name.replace(":", "_") android { namespace = "com.example.mylibrary.$normalizedName" compileSdk = 33 defaultConfig { minSdk = 24 testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } tasks.withType().configureEach { kotlinOptions { jvmTarget = JavaVersion.VERSION_11.toString() } } dependencies { /* ... */ }

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With many build scripts plugins { id("com.android.library") id("org.jetbrains.kotlin.android") id("kotlin-kapt") } val normalizedName = name.replace(":", "_") android { namespace = "com.example.mylibrary.$normalizedName" compileSdk = 33 defaultConfig { minSdk = 24 testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } tasks.withType().configureEach { kotlinOptions { jvmTarget = JavaVersion.VERSION_11.toString() } } dependencies { /* ... */ }

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With many build scripts plugins { id("com.android.library") id("org.jetbrains.kotlin.android") id("kotlin-kapt") } val normalizedName = name.replace(":", "_") android { namespace = "com.example.mylibrary.$normalizedName" compileSdk = 33 defaultConfig { minSdk = 24 testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } tasks.withType().configureEach { kotlinOptions { jvmTarget = JavaVersion.VERSION_11.toString() } } dependencies { /* ... */ }

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With many build scripts plugins { id("com.android.library") id("org.jetbrains.kotlin.android") id("kotlin-kapt") } val normalizedName = name.replace(":", "_") android { namespace = "com.example.mylibrary.$normalizedName" compileSdk = 33 defaultConfig { minSdk = 24 testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } tasks.withType().configureEach { kotlinOptions { jvmTarget = JavaVersion.VERSION_11.toString() } } dependencies { /* ... */ }

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With many build scripts plugins { id("com.android.library") id("org.jetbrains.kotlin.android") id("kotlin-kapt") } val normalizedName = name.replace(":", "_") android { namespace = "com.example.mylibrary.$normalizedName" compileSdk = 33 defaultConfig { minSdk = 24 testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } tasks.withType().configureEach { kotlinOptions { jvmTarget = JavaVersion.VERSION_11.toString() } } dependencies { /* ... */ }

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With many build scripts plugins { id("com.android.library") id("org.jetbrains.kotlin.android") id("kotlin-kapt") } val normalizedName = name.replace(":", "_") android { namespace = "com.example.mylibrary.$normalizedName" compileSdk = 33 defaultConfig { minSdk = 24 testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } tasks.withType().configureEach { kotlinOptions { jvmTarget = JavaVersion.VERSION_11.toString() } } dependencies { /* ... */ }

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Growing pains This is when the real growing pains start to show their face.

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Growing pains This is when the real growing pains start to show their face. • Duplication across build scripts

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Growing pains This is when the real growing pains start to show their face. • Duplication across build scripts • Misconfiguration going unnoticed

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Growing pains This is when the real growing pains start to show their face. • Duplication across build scripts • Misconfiguration going unnoticed • Larger surface area to maintain

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Growing pains This is when the real growing pains start to show their face. • Duplication across build scripts • Misconfiguration going unnoticed • Larger surface area to maintain • Tedious and slow iterations/migrations

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Let's start extracting // layer_1/module_1_20/build.gradle.kts plugins { id("com.android.library") id("org.jetbrains.kotlin.android") id("kotlin-kapt") } val normalizedName = name.replace(":", "_") android { namespace = "com.example.mylibrary.$normalizedName" compileSdk = 33 defaultConfig { minSdk = 24 testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } tasks.withType().configureEach { kotlinOptions { jvmTarget = JavaVersion.VERSION_11.toString() } } dependencies { /* ... */ }

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Let's start searching for advice

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Applying what the internet says // build.gradle.kts subprojects { android { compileSdk = 33 defaultConfig { minSdk = 24 } } }

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Applying what the internet says // build.gradle.kts subprojects { android { // ERROR: Unresolved reference 'android'. compileSdk = 33 defaultConfig { minSdk = 24 } } }

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Yes, we can fix this... // build.gradle.kts subprojects { plugins.withId("com.android.application") { configureAndroid(project) } plugins.withId("com.android.library") { configureAndroid(project) } } fun configureAndroid(project: Project) { project.extensions.configure("android") { compileSdkVersion(33) defaultConfig { minSdk = 24 } } }

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Tip #1 Avoid using allprojects {} and subprojects {} because:

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Tip #1 Avoid using allprojects {} and subprojects {} because: • Breaks isolation5 5 https://docs.gradle.org/current/userguide/sharing_build_logic_between_subprojects.html#sec:convention_plugins_vs_cross_configuration

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Tip #1 Avoid using allprojects {} and subprojects {} because: • Breaks isolation5 • Performance hit 5 https://docs.gradle.org/current/userguide/sharing_build_logic_between_subprojects.html#sec:convention_plugins_vs_cross_configuration

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Tip #1 Avoid using allprojects {} and subprojects {} because: • Breaks isolation5 • Performance hit • Hard to debug 5 https://docs.gradle.org/current/userguide/sharing_build_logic_between_subprojects.html#sec:convention_plugins_vs_cross_configuration

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Tip #1 Avoid using allprojects {} and subprojects {} because: • Breaks isolation • Performance hit • Hard to debug Instead Use pre-compiled scripts or convention plugins

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What are they A pre-compiled script6 refers to a reusable build script file, that encapsulates shared build logic (such as configurations and dependencies) for consistent use across multiple projects. 6 https://docs.gradle.org/current/userguide/implementing_gradle_plugins_precompiled.html

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What are they A pre-compiled script refers to a reusable build script file, that encapsulates shared build logic (such as configurations and dependencies) for consistent use across multiple projects. A convention plugin refers to a reusable Gradle binary plugin, that encapsulates shared build logic (such as configurations and dependencies) for consistent use across multiple projects.

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They are the same picture.

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Are they the same? Both pre-compiled scripts and convention plugins:

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Are they the same? Both pre-compiled scripts and convention plugins: • Written in Groovy or Kotlin DSL

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Are they the same? Both pre-compiled scripts and convention plugins: • Written in Groovy or Kotlin DSL • Encapsulate common, shared build logic

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Are they the same? Both pre-compiled scripts and convention plugins: • Written in Groovy or Kotlin DSL • Encapsulate common, shared build logic • Are simply plugins after all

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Let's start with pre-compiled scripts

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Pre-compiled scripts $ mkdir buildSrc $ touch buildSrc/build.gradle.kts // buildSrc/build.gradle.kts plugins { `kotlin-dsl` `kotlin-dsl-precompiled-script-plugins` // Enables Kotlin DSL for precompiled script plugins } dependencies { } repositories { google() mavenCentral() gradlePluginPortal() }

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Let's take a library build script plugins { id("com.android.library") id("org.jetbrains.kotlin.android") id("kotlin-kapt") } val normalizedName = name.replace(":","_") android { namespace = "com.example.mylibrary.$normalizedName" compileSdk = 33 defaultConfig { minSdk = 24 testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } tasks.withType().configureEach { kotlinOptions { jvmTarget = JavaVersion.VERSION_11.toString() } } dependencies { /* ... */ }

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sample.android.library.gradle.kts plugins { id("com.android.library") id("org.jetbrains.kotlin.android") id("kotlin-kapt") } val normalizedName = name.replace(":","_") android { namespace = "com.example.mylibrary.$normalizedName" compileSdk = 33 defaultConfig { minSdk = 24 testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner" } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } tasks.withType().configureEach { kotlinOptions { jvmTarget = JavaVersion.VERSION_11.toString() } } dependencies { /* ... */ }

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The generated code // buildSrc/build/generated-sources/kotlin-dsl-plugins/kotlin/Sample_android_libraryPlugin.kt public class Sample_android_libraryPlugin : org.gradle.api.Plugin { override fun apply(target: org.gradle.api.Project) { try { Class .forName("Sample_android_library_gradle") .getDeclaredConstructor( org.gradle.api.Project::class.java, org.gradle.api.Project::class.java ) .newInstance(target, target) } catch (e: java.lang.reflect.InvocationTargetException) { throw e.targetException } } }

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Applying the plugin // layer_1/module_1_20/build.gradle.kts plugins { id("sample.android.library") } dependencies { /* ... */ }

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Successfully extracted build logic Now we just need to apply to all build scripts.

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What about the root project? // build.gradle.kts plugins { id("org.jetbrains.kotlin.jvm") version("2.1.0") apply false id("com.android.application") version ("8.7.2") apply false id("com.android.library") version ("8.7.2") apply false }

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sample.root.gradle.kts plugins { }

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Where to pin them instead? // buildSrc/build.gradle.kts plugins { `kotlin-dsl` `kotlin-dsl-precompiled-script-plugins` } dependencies { implementation("com.android.tools.build:gradle:8.7.2") implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:2.1.0") } repositories { google() mavenCentral() gradlePluginPortal() }

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Applying the plugin // build.gradle.kts plugins { id("sample.android.root") }

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✅ All good, right?

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Tip #2 Avoid using buildSrc:

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Tip #2 Avoid using buildSrc: • It's a special directory, only one can exist

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Tip #2 Avoid using buildSrc: • It's a special directory, only one can exist • Added to the root project classpath

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Tip #2 Avoid using buildSrc: • It's a special directory, only one can exist • Added to the root project classpath • Any change7 causes the whole project to become out-of-date8 8 https://docs.gradle.org/current/userguide/sharing_build_logic_between_subprojects.html#sec:using_buildsrc 7 Unless you use --no-rebuild

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Tip #2 Avoid using buildSrc: • It's a special directory, only one can exist • Added to the root project classpath • Any change causes the whole project to become out-of-date Instead Use composite builds (also known as includedBuild())9 9 https://medium.com/proandroiddev/stop-using-gradle-buildsrc-use-composite-builds-instead-3c38ac7a2ab3

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Migrating to composite builds $ mv buildSrc build-logic // settings.gradle.kts rootProject.name="sample-gradle-project" includeBuild ("build-logic") include (":app") include (":layer_0:module_0_1") include (":layer_0:module_0_2") include (":layer_0:module_0_3") include (":layer_0:module_0_4") include (":layer_0:module_0_5") include (":layer_0:module_0_6") include (":layer_0:module_0_7") include (":layer_0:module_0_8") include (":layer_0:module_0_9") // ...

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✅ Sync and ready to go

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Migrating to convention plugins // build-logic/build.gradle.kts plugins { `kotlin-dsl` `kotlin-dsl-precompiled-script-plugins` // Enables Kotlin DSL for precompiled script plugins } dependencies { implementation("com.android.tools.build:gradle:8.7.2") implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:2.1.0") } repositories { google() mavenCentral() gradlePluginPortal() }

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Migrating to convention plugins // build-logic/build.gradle.kts plugins { `kotlin-dsl` } dependencies { implementation("com.android.tools.build:gradle:8.7.2") implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:2.1.0") } gradlePlugin { plugins { } } repositories { google() mavenCentral() gradlePluginPortal() }

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Migrating to convention plugins // build-logic/build.gradle.kts plugins { /* .. */} dependencies { /* .. */} gradlePlugin { plugins { create("root") { id = "sample.$name" implementationClass = "convention.SampleRootPlugin" version = "1.0.0" } create("android.library") { id = "sample.$name" implementationClass = "convention.SampleAndroidLibraryPlugin" version = "1.0.0" } create("android.application") { id = "sample.$name" implementationClass = "convention.SampleAndroidApplicationPlugin" version = "1.0.0" } } } repositories { /* .. */ }

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Migrating to convention plugins // build-logic/src/main/kotlin/convention/SampleRootPlugin.kt internal class SampleRootPlugin : Plugin { override fun apply(project: Project) { require(project == project.rootProject) { "Plugin must be applied to root project!" } } }

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Migrating to convention plugins internal class SampleAndroidApplicationPlugin : Plugin { override fun apply(project: Project) { with(project) { plugins.apply("com.android.library") plugins.apply("org.jetbrains.kotlin.android") plugins.apply("kotlin-kapt") extensions.getByType(ApplicationExtension::class.java).apply { compileSdk = 33 defaultConfig { applicationId = "com.example.myapplication" minSdk = 24 targetSdk = 33 } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } tasks.withType().configureEach { kotlinOptions { jvmTarget = JavaVersion.VERSION_11.toString() } } dependencies.apply { add("implementation", "androidx.appcompat:appcompat:1.6.1") // ... } } } }

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Migrating to convention plugins internal class SampleAndroidApplicationPlugin : Plugin { override fun apply(project: Project) { with(project) { plugins.apply("com.android.library") plugins.apply("org.jetbrains.kotlin.android") plugins.apply("kotlin-kapt") extensions.getByType(ApplicationExtension::class.java).apply { compileSdk = 33 defaultConfig { applicationId = "com.example.myapplication" minSdk = 24 targetSdk = 33 } compileOptions { sourceCompatibility = JavaVersion.VERSION_11 targetCompatibility = JavaVersion.VERSION_11 } } tasks.withType().configureEach { kotlinOptions { jvmTarget = JavaVersion.VERSION_11.toString() } } dependencies.apply { add("implementation", "androidx.appcompat:appcompat:1.6.1") // ... } } } }

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Migrating to convention plugins // app/build.gradle.kts plugins { id("sample.android.application") } dependencies { /* ... */ }

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Done

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Achievements, so far...

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Achievements, so far... • We went from 1000s of lines to 100s of lines of code

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Achievements, so far... • We went from 1000s of lines to 100s of lines of code • Spreading over in 100s of projects to 1

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Achievements, so far... • We went from 1000s of lines to 100s of lines of code • Spreading over in 100s of projects to 1 • We now own many Gradle plugins (locally)

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There's more... // settings.gradle.kts rootProject.name="sample-gradle-project" includeBuild ("build-logic") include (":app") include (":layer_0:module_0_1") include (":layer_0:module_0_2") include (":layer_0:module_0_3") include (":layer_0:module_0_4") include (":layer_0:module_0_5") include (":layer_0:module_0_6") include (":layer_0:module_0_7") include (":layer_0:module_0_8") include (":layer_0:module_0_9") include (":layer_0:module_0_10") include (":layer_0:module_0_11") // ...

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There's more... // settings.gradle.kts // ... enableFeaturePreview("STABLE_CONFIGURATION_CACHE") enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS") dependencyResolutionManagement { repositories { google().content { includeGroupByRegex("com\\.google.*") includeGroupByRegex("com\\.android.*") includeGroupByRegex("androidx.*") } mavenCentral() } } buildCache { local { isEnabled = true } }

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There's logic in settings kts // settings.gradle.kts // ... enableFeaturePreview("STABLE_CONFIGURATION_CACHE") enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS") dependencyResolutionManagement { repositories { google().content { includeGroupByRegex("com\\.google.*") includeGroupByRegex("com\\.android.*") includeGroupByRegex("androidx.*") } mavenCentral() } } buildCache { local { isEnabled = true } }

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There's logic in settings kts // settings.gradle.kts // ... enableFeaturePreview("STABLE_CONFIGURATION_CACHE") enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS") dependencyResolutionManagement { repositories { google().content { includeGroupByRegex("com\\.google.*") includeGroupByRegex("com\\.android.*") includeGroupByRegex("androidx.*") } mavenCentral() } } buildCache { local { isEnabled = true } }

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There's logic in settings kts // settings.gradle.kts // ... enableFeaturePreview("STABLE_CONFIGURATION_CACHE") enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS") dependencyResolutionManagement { repositories { google().content { includeGroupByRegex("com\\.google.*") includeGroupByRegex("com\\.android.*") includeGroupByRegex("androidx.*") } mavenCentral() } } buildCache { local { isEnabled = true } }

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Creating a settings convention plugin $ mkdir build-logic-settings $ touch build-logic-settings/build.gradle.kts plugins { `kotlin-dsl` } gradlePlugin { plugins { create("settings") { id = "sample.$name" implementationClass = "convention.SampleSettingsPlugin" } } } repositories { gradlePluginPortal() }

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Creating a settings convention plugin // build-logic-settings/src/main/kotlin/convention/SampleSettingsPlugin.kt class SampleSettingsPlugin : Plugin { override fun apply(settings: Settings) { with(settings) { enableFeaturePreview("STABLE_CONFIGURATION_CACHE") enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS") pluginManagement { configurePluginManagement() } dependencyResolutionManagement { configureRepositories() } pluginManager.apply(GradleBuildCachePlugin::class.java) } } }

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Creating a settings convention plugin // build-logic-settings/src/main/kotlin/convention/SampleSettingsPlugin.kt class SampleSettingsPlugin : Plugin { override fun apply(settings: Settings) { with(settings) { enableFeaturePreview("STABLE_CONFIGURATION_CACHE") enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS") pluginManagement { configurePluginManagement() } dependencyResolutionManagement { configureRepositories() } pluginManager.apply(GradleBuildCachePlugin::class.java) } } }

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Creating a settings convention plugin // build-logic-settings/src/main/kotlin/convention/SampleSettingsPlugin.kt class SampleSettingsPlugin : Plugin { override fun apply(settings: Settings) { with(settings) { enableFeaturePreview("STABLE_CONFIGURATION_CACHE") enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS") pluginManagement { configurePluginManagement() } dependencyResolutionManagement { configureRepositories() } pluginManager.apply(GradleBuildCachePlugin::class.java) } } }

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Creating a settings convention plugin // settings.gradle.kts rootProject.name="sample-gradle-project" pluginManagement { includeBuild("build-logic-settings") } plugins { id("sample.settings") }

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✅ Pretty much done

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Tip #3 Android Grade Plugin 8.0.010 now ships with a settings plugin artifact: plugins { id("com.android.settings") version "" } Then we can tweak a few props via the android11 extension. 11 https://developer.android.com/reference/tools/gradle-api/8.0/com/android/build/api/dsl/SettingsExtension 10 https://developer.android.com/build/releases/past-releases/agp-8-0-0-release-notes

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Apply directly // settings.gradle.kts rootProject.name="sample-gradle-project" pluginManagement { includeBuild("build-logic-settings") } plugins { id("sample.settings") id("com.android.settings") version "8.7.2" }

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Apply to settings convention plugin plugins { `kotlin-dsl` } dependencies { implementation("com.android.settings:com.android.settings.gradle.plugin:8.7.2") } gradlePlugin { plugins { create("settings") { id = "sample.$name" implementationClass = "convention.SampleSettingsPlugin" } } } repositories { google() gradlePluginPortal() }

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Apply to settings convention plugin // build-logic-settings/src/main/kotlin/convention/SampleSettingsPlugin.kt import com.android.build.api.dsl.SettingsExtension import com.android.build.gradle.SettingsPlugin class SampleSettingsPlugin : Plugin { override fun apply(settings: Settings) { with(settings) { // ... pluginManager.apply(SettingsPlugin::class.java) extensions.getByType().apply { minSdk = 24 compileSdk = 33 } } } }

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Recap We now have:

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Recap We now have: 1. Understand how to structure build logic

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Recap We now have: 1. Understand how to structure build logic 2. Creating and applying convention plugins

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Not so fast

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But I use Compose UI... // layer_1/module_1_19/build.gradle.kts plugins { id("sample.android.library") id("org.jetbrains.kotlin.plugin.compose") id("org.jetbrains.compose") } android { buildFeatures { compose = true } } dependencies { debugImplementation("org.jetbrains.compose.ui:ui-tooling-preview:1.7.1") debugImplementation("org.jetbrains.compose.components:components-ui-tooling-preview:1.7.1") implementation("org.jetbrains.compose.ui:ui:1.7.1") implementation("org.jetbrains.compose.runtime:runtime:1.7.1") implementation("org.jetbrains.compose.material3:material3:1.7.1") implementation("org.jetbrains.compose.foundation:foundation:1.7.1") implementation("org.jetbrains.compose.ui:ui-tooling:1.7.1") }

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But I use Dagger Hilt... // layer_1/module_1_21/build.gradle.kts plugins { id("sample.android.library") id("kotlin-kapt") id("com.google.dagger.hilt.android") } dependencies { implementation("com.google.dagger:hilt-android:2.53.1") kapt("com.google.dagger:hilt-compiler:2.53.1") } kapt { correctErrorTypes = true }

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What if... // layer_1/module_1_20/build.gradle.kts plugins { id("sample.android.library") } sampleCompany { features { compose() dagger() } }

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How do I implement it12 12 https://github.com/anthonymonori/sample-gradle-project/pull/1/files

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How do I implement it12 1. Create a base plugin 12 https://github.com/anthonymonori/sample-gradle-project/pull/1/files

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How do I implement it12 1. Create a base plugin 2. Create a @DslMarker annotation 12 https://github.com/anthonymonori/sample-gradle-project/pull/1/files

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How do I implement it12 1. Create a base plugin 2. Create a @DslMarker annotation 3. Create a core DSL class sample { } 12 https://github.com/anthonymonori/sample-gradle-project/pull/1/files

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How do I implement it12 1. Create a base plugin 2. Create a @DslMarker annotation 3. Create a core DSL class sample { } 4. Create a nested feature DSL class features { } 12 https://github.com/anthonymonori/sample-gradle-project/pull/1/files

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How do I implement it12 1. Create a base plugin 2. Create a @DslMarker annotation 3. Create a core DSL class sample { } 4. Create a nested feature DSL class features { } 5. Create the features 12 https://github.com/anthonymonori/sample-gradle-project/pull/1/files

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Set up the base plugin // build-logic/src/main/kotlin/com/sample/SampleBasePlugin.kt class SampleBasePlugin : Plugin { override fun apply(project: Project) { with(project) { val sampleExtension = extensions.create("sample", SampleCompanyExtension::class.java) pluginManager.withPlugin("com.android.application") { configure { sampleExtension.androidExtension = this } } project.pluginManager.withPlugin("com.android.library") { configure { sampleExtension.androidExtension = this } } sampleExtension.applyTo(this) } } }

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Set up the base plugin // build-logic/src/main/kotlin/com/sample/SampleBasePlugin.kt class SampleBasePlugin : Plugin { override fun apply(project: Project) { with(project) { val sampleExtension = extensions.create("sample", SampleCompanyExtension::class.java) pluginManager.withPlugin("com.android.application") { configure { sampleExtension.androidExtension = this } } project.pluginManager.withPlugin("com.android.library") { configure { sampleExtension.androidExtension = this } } sampleExtension.applyTo(this) } } }

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Set up the marker and core DSL // build-logic/src/main/kotlin/com/sample/SampleCompanyHandler.kt @DslMarker annotation class SampleCompanyExtensionMarker @SampleCompanyExtensionMarker open class SampleCompanyExtension @Inject internal constructor(objects: ObjectFactory) { private val featuresHandler = objects.newInstance(FeaturesHandler::class.java) fun features(action: Action) { action.execute(featuresHandler) } internal fun applyTo(project: Project) { project.afterEvaluate { featuresHandler.applyTo(project) } } }

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Set up the marker and core DSL // build-logic/src/main/kotlin/com/sample/SampleCompanyHandler.kt @DslMarker annotation class SampleCompanyExtensionMarker @SampleCompanyExtensionMarker open class SampleCompanyExtension @Inject internal constructor(objects: ObjectFactory) { private val featuresHandler = objects.newInstance(FeaturesHandler::class.java) fun features(action: Action) { action.execute(featuresHandler) } internal fun applyTo(project: Project) { project.afterEvaluate { featuresHandler.applyTo(project) } } }

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Set up the marker and core DSL // build-logic/src/main/kotlin/com/sample/SampleCompanyHandler.kt @DslMarker annotation class SampleCompanyExtensionMarker @SampleCompanyExtensionMarker open class SampleCompanyExtension @Inject internal constructor(objects: ObjectFactory) { private val featuresHandler = objects.newInstance(FeaturesHandler::class.java) fun features(action: Action) { action.execute(featuresHandler) } internal fun applyTo(project: Project) { project.afterEvaluate { featuresHandler.applyTo(project) } } }

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Set up the feature DSL // build-logic/src/main/kotlin/com/sample/features/FeatureHandler.kt @SampleCompanyExtensionMarker abstract class FeaturesHandler @Inject internal constructor(objects: ObjectFactory) { private val composeHandler = objects.newInstance() private val daggerHandler = objects.newInstance() internal fun applyTo(project: Project) { composeHandler.applyTo(project) daggerHandler.applyTo(project) } fun compose(action: Action? = null) { composeHandler.enable() action?.execute(composeHandler) } fun dagger(action: Action? = null) { daggerHandler.enable() action?.execute(daggerHandler) } }

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Set up the feature DSL // build-logic/src/main/kotlin/com/sample/features/FeatureHandler.kt @SampleCompanyExtensionMarker abstract class FeaturesHandler @Inject internal constructor(objects: ObjectFactory) { private val composeHandler = objects.newInstance() private val daggerHandler = objects.newInstance() internal fun applyTo(project: Project) { composeHandler.applyTo(project) daggerHandler.applyTo(project) } fun compose(action: Action? = null) { composeHandler.enable() action?.execute(composeHandler) } fun dagger(action: Action? = null) { daggerHandler.enable() action?.execute(daggerHandler) } }

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Compose UI feature // build-logic/src/main/kotlin/com/sample/features/ComposeHandler.kt @SampleCompanyExtensionMarker abstract class ComposeHandler @Inject internal constructor(objects: ObjectFactory) { private val enabled = objects.property().convention(false) internal var androidExtension: CommonExtension<*, *, *, *, *, *>? = null internal fun enable() { enabled.set(true) enabled.disallowChanges() androidExtension.apply { buildFeatures { compose = true } } } internal fun applyTo(project: Project) { if (enabled.get()) { project.plugins.apply("org.jetbrains.kotlin.plugin.compose") project.plugins.apply("org.jetbrains.compose") project.dependencies.apply { add("implementation", "org.jetbrains.compose.ui:ui:$composeVersion") add("implementation", "org.jetbrains.compose.runtime:runtime:$composeVersion") // ... } } } }

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Compose UI feature // build-logic/src/main/kotlin/com/sample/features/ComposeHandler.kt @SampleCompanyExtensionMarker abstract class ComposeHandler @Inject internal constructor(objects: ObjectFactory) { private val enabled = objects.property().convention(false) internal var androidExtension: CommonExtension<*, *, *, *, *, *>? = null internal fun enable() { enabled.set(true) enabled.disallowChanges() androidExtension.apply { buildFeatures { compose = true } } } internal fun applyTo(project: Project) { if (enabled.get()) { project.plugins.apply("org.jetbrains.kotlin.plugin.compose") project.plugins.apply("org.jetbrains.compose") project.dependencies.apply { add("implementation", "org.jetbrains.compose.ui:ui:$composeVersion") add("implementation", "org.jetbrains.compose.runtime:runtime:$composeVersion") // ... } } } }

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Providing a custom DSL

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Providing a custom DSL • Declarative, discoverable

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Providing a custom DSL • Declarative, discoverable • Hides the complexity away

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Providing a custom DSL • Declarative, discoverable • Hides the complexity away • Allows for easy migrations

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Changing Dagger KAPT to KSP // build-logic/src/main/kotlin/com/sample/features/DaggerHandler.kt abstract class DaggerHandler @Inject internal constructor(objects: ObjectFactory) { // ... private fun Project.setupDaggerCompiler() { if (useKsp.get()) { pluginManager.apply("com.google.devtools.ksp") dependencies.apply { add("ksp", daggerHiltCompiler) } } else { pluginManager.apply("kotlin-kapt") dependencies.apply { add("kapt", daggerHiltCompiler) } } } }

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How about discoverability

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No content

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Acknowledgements

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Herding Elephants 13 13 https://developer.squareup.com/blog/herding-elephants/

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NowInAndroid 14 14 https://github.com/android/nowinandroid

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slackhq/foundry 15 15 https://github.com/slackhq/foundry

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Find me on the Fediverse androiddev.social/@antal

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Thank you, question?