Writing backwards compatible Gradle plugins - droidcon Berlin 2022

Slides accompanying my talk about "Writing backwards compatible Gradle plugins" held at droidcon Berlin 2022

Transcript

1. Writing backwards compatible Gradle plugins Simon Schiller • droidcon Berlin 2022 simonxschiller simonschiller simonschiller.io
2. Gradle plugins • Fundamental building blocks of Gradle • Used to customize and extend build logic • Plugins typically interact with other plugins
3. Writing Gradle plugins class SamplePlugin : Plugin<Project> { override fun apply(project: Project) { // Plugin logic } }
4. Writing Gradle plugins class SamplePlugin : Plugin<Project> { override fun apply(project: Project) { // Plugin logic } } # Located under META-INF/gradle-plugins/com.droidcon.sample.properties implementation-class=com.droidcon.sample.SamplePlugin
5. Interacting with other plugins // To interact with AGP we need a dependency on AGP dependencies { implementation("com.android.tools.build:gradle:7.0.0") }
6. Resources around writing Gradle plugins • Using Gradle Plugins • Developing Custom Gradle Plugins • Extend the Android Gradle plugin • Gradle and AGP Build APIs - How to write a plugin
7. Backwards compatibility
8. Example - Manifest printing plugin plugins { id("com.droidcon.sample") version "1.0.0" id("com.android.application") version "7.0.0" }
9. Example - Manifest printing plugin plugins { id("com.droidcon.sample") version "1.0.0" id("com.android.application") version "7.0.0" } > ./gradlew printReleaseManifest > > <?xml version="1.0" encoding="utf-8"?> > <manifest xmlns:android="http://schemas.android.com/apk/res/android" > package="com.droidcon.sample" > > > <application android:hasCode="false" /> > > </manifest>
10. Backwards compatibility com.droidcon.sample 󰳕 AGP 7.0.0
11. Backwards compatibility com.droidcon.sample 󰳕 AGP 7.0.0 󰞵 AGP 4.2.0 󰠁 AGP 4.1.0
12. Backwards compatibility id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } }
13. Backwards compatibility id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } }
14. Backwards compatibility id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } }
15. Backwards compatibility id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } } > ./gradlew printReleaseManifest > > <?xml version="1.0" encoding="utf-8"?> > <manifest xmlns:android="...">
16. Backwards compatibility id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } } id("com.android.application") version "4.2.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { minifyEnabled(true) } } }
17. Backwards compatibility id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } } id("com.android.application") version "4.2.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { minifyEnabled(true) } } }
18. Backwards compatibility id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } } id("com.android.application") version "4.2.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { minifyEnabled(true) } } } > ./gradlew printReleaseManifest > > Script compilation error: > minifyEnabled(true) > ^ Unresolved reference: minifyEnabled
19. What is happening? project com.droidcon.sample com.android.application 4.2.0
20. What is happening? project com.droidcon.sample com.android.application com.android.application 7.0.0 4.2.0
21. What is happening? project com.droidcon.sample com.android.application com.android.application 7.0.0 4.2.0
22. What is happening? project com.droidcon.sample com.android.application com.android.application 7.0.0 4.2.0
23. What is happening? // In our com.droidcon.sample plugin dependencies { implementation("com.android.tools.build:gradle:7.0.0") } project com.droidcon.sample com.android.application com.android.application 7.0.0 4.2.0 <!-- com.droidcon.sample pom.xml --> <dependency> <groupId>com.android.tools.build</groupId> <artifactId>gradle</artifactId> <version>7.0.0</version> </dependency>
24. How to resolve it // In our com.droidcon.sample plugin dependencies { compileOnly("com.android.tools.build:gradle:7.0.0") } project com.droidcon.sample com.android.application 4.2.0 <!-- com.droidcon.sample pom.xml --> <dependencies> </dependencies>
25. How to resolve it // In our com.droidcon.sample plugin dependencies { compileOnly("com.android.tools.build:gradle:7.0.0") } project com.droidcon.sample com.android.application 4.2.0
26. How to resolve it // In the plugin code project.plugins.withId("com.android.application") { // Code interacting with the Android Gradle plugin }
27. Does it work now? id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } } id("com.android.application") version "4.2.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { minifyEnabled(true) } } }
28. Does it work now? id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } } id("com.android.application") version "4.2.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { minifyEnabled(true) } } } > ./gradlew printReleaseManifest > > <?xml version="1.0" encoding="utf-8"?> > <manifest xmlns:android="...">
29. Does it work now? id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } } id("com.android.application") version "4.2.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { minifyEnabled(true) } } } > ./gradlew printReleaseManifest > > <?xml version="1.0" encoding="utf-8"?> > <manifest xmlns:android="..."> > ./gradlew printReleaseManifest > > FAILURE: Build failed with an exception > > * Exception is: > java.lang.NoClassDefFoundError: ...
30. The problem Version A sample.Foo.foo() sample.Bar.bar() sample.Baz.baz() Version B sample.Foo.foo() sample.Bar.change() sample.Baz.baz() Version C sample.Foo.change() sample.Bar.change() sample.Baz.baz()
31. Locating the merged manifest - AGP 4.1.0 import com.android.build.api.artifact.ArtifactType import com.android.build.api.dsl.ApplicationExtension val extension = project.extensions.getByType(ApplicationExtension::class.java) extension.onVariantProperties { variant -> val manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) // Do something with the manifest }
32. Locating the merged manifest - AGP 4.1.0 import com.android.build.api.artifact.ArtifactType import com.android.build.api.dsl.ApplicationExtension val extension = project.extensions.getByType(ApplicationExtension::class.java) extension.onVariantProperties { variant -> val manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) // Do something with the manifest }
33. Locating the merged manifest - AGP 4.1.0 import com.android.build.api.artifact.ArtifactType import com.android.build.api.dsl.ApplicationExtension val extension = project.extensions.getByType(ApplicationExtension::class.java) extension.onVariantProperties { variant -> val manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) // Do something with the manifest }
34. Locating the merged manifest - AGP 4.1.0 import com.android.build.api.artifact.ArtifactType import com.android.build.api.dsl.ApplicationExtension val extension = project.extensions.getByType(ApplicationExtension::class.java) extension.onVariantProperties { variant -> val manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) // Do something with the manifest }
35. Locating the merged manifest - AGP 4.2.0 import com.android.build.api.artifact.ArtifactType import com.android.build.api.extension.AndroidComponentsExtension val extension = project.extensions.getByType(AndroidComponentsExtension::class.java) extension.onVariants { variant -> val manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) // Do something with the manifest }
36. Locating the merged manifest - AGP 4.2.0 import com.android.build.api.artifact.ArtifactType import com.android.build.api.extension.AndroidComponentsExtension val extension = project.extensions.getByType(AndroidComponentsExtension::class.java) extension.onVariants { variant -> val manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) // Do something with the manifest }
37. Locating the merged manifest - AGP 7.0.0 import com.android.build.api.artifact.SingleArtifact import com.android.build.api.variant.AndroidComponentsExtension val extension = project.extensions.getByType(AndroidComponentsExtension::class.java) extension.onVariants { variant -> val manifest = variant.artifacts.get(SingleArtifact.MERGED_MANIFEST) // Do something with the manifest }
38. Locating the merged manifest - AGP 7.0.0 import com.android.build.api.artifact.SingleArtifact import com.android.build.api.variant.AndroidComponentsExtension val extension = project.extensions.getByType(AndroidComponentsExtension::class.java) extension.onVariants { variant -> val manifest = variant.artifacts.get(SingleArtifact.MERGED_MANIFEST) // Do something with the manifest }
39. Which version are we running against? Run code specific to A Run code specific to B Run code specific to C How to resolve it A B C
40. Which version are we running against? Run code specific to A Run code specific to B Run code specific to C How to resolve it A B C
41. 1. Android Gradle plugin APIs import com.android.Version val version = Version.ANDROID_GRADLE_PLUGIN_VERSION // 7.0.0 return VersionNumber.parse(version)
42. 1. Android Gradle plugin APIs import com.android.Version val version = Version.ANDROID_GRADLE_PLUGIN_VERSION // 7.0.0 return VersionNumber.parse(version) // In your build.gradle.kts compileOnly("com.android.tools:common:30.0.0")
43. 2. Gradle APIs // Get all resolved Gradle classpath dependencies val buildscript = project.rootProject.buildscript val config = buildscript.configurations.getByName("classpath") val artifacts = config.resolvedConfiguration.resolvedArtifacts // Find the Android Gradle plugin dependency val androidGradlePlugin = artifacts.singleOrNull { it.moduleVersion.id.toString().startsWith("com.android.tools.build:gradle:") } ?: error("Could not determine Android Gradle plugin version") // Extract the resolved Android Gradle plugin version val version = androidGradlePlugin.moduleVersion.id.version // 7.0.0 return VersionNumber.parse(version)
44. 2. Gradle APIs // Get all resolved Gradle classpath dependencies val buildscript = project.rootProject.buildscript val config = buildscript.configurations.getByName("classpath") val artifacts = config.resolvedConfiguration.resolvedArtifacts // Find the Android Gradle plugin dependency val androidGradlePlugin = artifacts.singleOrNull { it.moduleVersion.id.toString().startsWith("com.android.tools.build:gradle:") } ?: error("Could not determine Android Gradle plugin version") // Extract the resolved Android Gradle plugin version val version = androidGradlePlugin.moduleVersion.id.version // 7.0.0 return VersionNumber.parse(version)
45. 2. Gradle APIs // Get all resolved Gradle classpath dependencies val buildscript = project.rootProject.buildscript val config = buildscript.configurations.getByName("classpath") val artifacts = config.resolvedConfiguration.resolvedArtifacts // Find the Android Gradle plugin dependency val androidGradlePlugin = artifacts.singleOrNull { it.moduleVersion.id.toString().startsWith("com.android.tools.build:gradle:") } ?: error("Could not determine Android Gradle plugin version") // Extract the resolved Android Gradle plugin version val version = androidGradlePlugin.moduleVersion.id.version // 7.0.0 return VersionNumber.parse(version)
46. 2. Gradle APIs // Get all resolved Gradle classpath dependencies val buildscript = project.rootProject.buildscript val config = buildscript.configurations.getByName("classpath") val artifacts = config.resolvedConfiguration.resolvedArtifacts // Find the Android Gradle plugin dependency val androidGradlePlugin = artifacts.singleOrNull { it.moduleVersion.id.toString().startsWith("com.android.tools.build:gradle:") } ?: error("Could not determine Android Gradle plugin version") // Extract the resolved Android Gradle plugin version val version = androidGradlePlugin.moduleVersion.id.version // 7.0.0 return VersionNumber.parse(version)
47. Which version are we running against? Run code specific to A Run code specific to B Run code specific to C How to resolve it A B C
48. Different code for different versions val callback = Action<Provider<RegularFile>> { manifest -> // Do something with the manifest } // Call the correct code depending on the available version val version = getAndroidGradlePluginVersion(project) when { version < VersionNumber.parse("4.1.0") -> error("Unsupported AGP version") version < VersionNumber.parse("4.2.0") -> handle4Dot1(project, callback) version < VersionNumber.parse("7.0.0") -> handle4Dot2(project, callback) else -> handle7Dot0(project, callback) }
49. Different code for different versions val callback = Action<Provider<RegularFile>> { manifest -> // Do something with the manifest } // Call the correct code depending on the available version val version = getAndroidGradlePluginVersion(project) when { version < VersionNumber.parse("4.1.0") -> error("Unsupported AGP version") version < VersionNumber.parse("4.2.0") -> handle4Dot1(project, callback) version < VersionNumber.parse("7.0.0") -> handle4Dot2(project, callback) else -> handle7Dot0(project, callback) }
50. Different code for different versions val callback = Action<Provider<RegularFile>> { manifest -> // Do something with the manifest } // Call the correct code depending on the available version val version = getAndroidGradlePluginVersion(project) when { version < VersionNumber.parse("4.1.0") -> error("Unsupported AGP version") version < VersionNumber.parse("4.2.0") -> handle4Dot1(project, callback) version < VersionNumber.parse("7.0.0") -> handle4Dot2(project, callback) else -> handle7Dot0(project, callback) }
51. Different code for different versions val callback = Action<Provider<RegularFile>> { manifest -> // Do something with the manifest } // Call the correct code depending on the available version val version = getAndroidGradlePluginVersion(project) when { version < VersionNumber.parse("4.1.0") -> error("Unsupported AGP version") version < VersionNumber.parse("4.2.0") -> handle4Dot1(project, callback) version < VersionNumber.parse("7.0.0") -> handle4Dot2(project, callback) else -> handle7Dot0(project, callback) }
52. Different code for different versions val callback = Action<Provider<RegularFile>> { manifest -> // Do something with the manifest } // Call the correct code depending on the available version val version = getAndroidGradlePluginVersion(project) when { version < VersionNumber.parse("4.1.0") -> error("Unsupported AGP version") version < VersionNumber.parse("4.2.0") -> handle4Dot1(project, callback) version < VersionNumber.parse("7.0.0") -> handle4Dot2(project, callback) else -> handle7Dot0(project, callback) }
53. Different code for different versions val callback = Action<Provider<RegularFile>> { manifest -> // Do something with the manifest } // Call the correct code depending on the available version val version = getAndroidGradlePluginVersion(project) when { version < VersionNumber.parse("4.1.0") -> error("Unsupported AGP version") version < VersionNumber.parse("4.2.0") -> handle4Dot1(project, callback) version < VersionNumber.parse("7.0.0") -> handle4Dot2(project, callback) else -> handle7Dot0(project, callback) }
54. Different code for different versions val callback = Action<Provider<RegularFile>> { manifest -> // Do something with the manifest } // Call the correct code depending on the available version val version = getAndroidGradlePluginVersion(project) when { version < VersionNumber.parse("4.1.0") -> error("Unsupported AGP version") version < VersionNumber.parse("4.2.0") -> handle4Dot1(project, callback) version < VersionNumber.parse("7.0.0") -> handle4Dot2(project, callback) else -> handle7Dot0(project, callback) }
55. Different code for different versions val callback = Action<Provider<RegularFile>> { manifest -> // Do something with the manifest } // Call the correct code depending on the available version val version = getAndroidGradlePluginVersion(project) when { version < VersionNumber.parse("4.1.0") -> error("Unsupported AGP version") version < VersionNumber.parse("4.2.0") -> handle4Dot1(project, callback) version < VersionNumber.parse("7.0.0") -> handle4Dot2(project, callback) else -> handle7Dot0(project, callback) } compileOnly("com.android.tools.build:gradle:4.1.0")
56. Different code for different versions val callback = Action<Provider<RegularFile>> { manifest -> // Do something with the manifest } // Call the correct code depending on the available version val version = getAndroidGradlePluginVersion(project) when { version < VersionNumber.parse("4.1.0") -> error("Unsupported AGP version") version < VersionNumber.parse("4.2.0") -> handle4Dot1(project, callback) version < VersionNumber.parse("7.0.0") -> handle4Dot2(project, callback) else -> handle7Dot0(project, callback) } compileOnly("com.android.tools.build:gradle:4.2.0")
57. 1. Reflection
58. 1. Reflection // Compatibility code for Android Gradle plugin 4.1.0 val android = project.extensions.getByName("android") val method = android::class.java.getMethod("onVariantProperties", Action::class.java) method.invoke(android, Action<Any> { variant -> val className = "com.android.build.api.artifact.ArtifactType" val enumClass = Class.forName("$className\$MERGED_MANIFEST") val enumInstance = enumClass.getField("INSTANCE").get(null) val artifacts = variant::class.java.getMethod("getArtifacts").invoke(variant) val getMethod = artifacts::class.java.getMethod("get", Class.forName(className)) val manifest = getMethod.invoke(artifacts, enumInstance) callback.execute(manifest) })
59. 1. Reflection // Compatibility code for Android Gradle plugin 4.1.0 val android = project.extensions.getByName("android") val method = android::class.java.getMethod("onVariantProperties", Action::class.java) method.invoke(android, Action<Any> { variant -> val className = "com.android.build.api.artifact.ArtifactType" val enumClass = Class.forName("$className\$MERGED_MANIFEST") val enumInstance = enumClass.getField("INSTANCE").get(null) val artifacts = variant::class.java.getMethod("getArtifacts").invoke(variant) val getMethod = artifacts::class.java.getMethod("get", Class.forName(className)) val manifest = getMethod.invoke(artifacts, enumInstance) callback.execute(manifest) })
60. 1. Reflection // Compatibility code for Android Gradle plugin 4.1.0 val android = project.extensions.getByName("android") val method = android::class.java.getMethod("onVariantProperties", Action::class.java) method.invoke(android, Action<Any> { variant -> val className = "com.android.build.api.artifact.ArtifactType" val enumClass = Class.forName("$className\$MERGED_MANIFEST") val enumInstance = enumClass.getField("INSTANCE").get(null) val artifacts = variant::class.java.getMethod("getArtifacts").invoke(variant) val getMethod = artifacts::class.java.getMethod("get", Class.forName(className)) val manifest = getMethod.invoke(artifacts, enumInstance) callback.execute(manifest) })
61. 1. Reflection // Compatibility code for Android Gradle plugin 4.1.0 val android = project.extensions.getByName("android") val method = android::class.java.getMethod("onVariantProperties", Action::class.java) method.invoke(android, Action<Any> { variant -> val className = "com.android.build.api.artifact.ArtifactType" val enumClass = Class.forName("$className\$MERGED_MANIFEST") val enumInstance = enumClass.getField("INSTANCE").get(null) val artifacts = variant::class.java.getMethod("getArtifacts").invoke(variant) val getMethod = artifacts::class.java.getMethod("get", Class.forName(className)) val manifest = getMethod.invoke(artifacts, enumInstance) callback.execute(manifest) })
62. 1. Reflection // Compatibility code for Android Gradle plugin 4.1.0 val android = project.extensions.getByName("android") val method = android::class.java.getMethod("onVariantProperties", Action::class.java) method.invoke(android, Action<Any> { variant -> val className = "com.android.build.api.artifact.ArtifactType" val enumClass = Class.forName("$className\$MERGED_MANIFEST") val enumInstance = enumClass.getField("INSTANCE").get(null) val artifacts = variant::class.java.getMethod("getArtifacts").invoke(variant) val getMethod = artifacts::class.java.getMethod("get", Class.forName(className)) val manifest = getMethod.invoke(artifacts, enumInstance) callback.execute(manifest) })
63. 2. Groovy
64. 2. Groovy // Compatibility code in src/main/groovy/Compat.groovy class Compat { static void handle4Dot1(Project project, Action callback) { project.android.onVariantProperties { variant -> def manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) callback.execute(manifest) } } static void handle4Dot2(Project project, Action callback) { ... } static void handle7Dot0(Project project, Action callback) { ... } }
65. // Compatibility code in src/main/groovy/Compat.groovy class Compat { static void handle4Dot1(Project project, Action callback) { project.android.onVariantProperties { variant -> def manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) callback.execute(manifest) } } static void handle4Dot2(Project project, Action callback) { ... } static void handle7Dot0(Project project, Action callback) { ... } } 2. Groovy
66. 2. Groovy // Compatibility code in src/main/groovy/Compat.groovy class Compat { static void handle4Dot1(Project project, Action callback) { project.android.onVariantProperties { variant -> def manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) callback.execute(manifest) } } static void handle4Dot2(Project project, Action callback) { ... } static void handle7Dot0(Project project, Action callback) { ... } }
67. 2. Groovy // Compatibility code in src/main/groovy/Compat.groovy class Compat { static void handle4Dot1(Project project, Action callback) { project.android.onVariantProperties { variant -> def manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) callback.execute(manifest) } } static void handle4Dot2(Project project, Action callback) { ... } static void handle7Dot0(Project project, Action callback) { ... } }
68. // Compatibility code in src/main/groovy/Compat.groovy class Compat { static void handle4Dot1(Project project, Action callback) { project.android.onVariantProperties { variant -> def manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) callback.execute(manifest) } } static void handle4Dot2(Project project, Action callback) { ... } static void handle7Dot0(Project project, Action callback) { ... } } 2. Groovy
69. 2. Groovy // In your build.gradle.kts plugins { id("org.gradle.groovy") } // Include dependencies in the Groovy classpath tasks.withType<GroovyCompile> { classpath = sourceSets.main.get().compileClasspath } // Include compiled Groovy classes in the Kotlin classpath tasks.withType<KotlinCompile> { classpath += files(sourceSets.main.get().groovy.classesDirectory) }
70. 2. Groovy // In your build.gradle.kts plugins { id("org.gradle.groovy") } // Include dependencies in the Groovy classpath tasks.withType<GroovyCompile> { classpath = sourceSets.main.get().compileClasspath } // Include compiled Groovy classes in the Kotlin classpath tasks.withType<KotlinCompile> { classpath += files(sourceSets.main.get().groovy.classesDirectory) } groovy
71. // In your build.gradle.kts plugins { id("org.gradle.groovy") } // Include dependencies in the Groovy classpath tasks.withType<GroovyCompile> { classpath = sourceSets.main.get().compileClasspath } // Include compiled Groovy classes in the Kotlin classpath tasks.withType<KotlinCompile> { classpath += files(sourceSets.main.get().groovy.classesDirectory) } 2. Groovy groovy dependencies
72. // In your build.gradle.kts plugins { id("org.gradle.groovy") } // Include dependencies in the Groovy classpath tasks.withType<GroovyCompile> { classpath = sourceSets.main.get().compileClasspath } // Include compiled Groovy classes in the Kotlin classpath tasks.withType<KotlinCompile> { classpath += files(sourceSets.main.get().groovy.classesDirectory) } 2. Groovy kotlin groovy dependencies
73. 3. Compile against multiple versions
74. 3. Compile against multiple versions val callback = Action<Provider<RegularFile>> { manifest -> // Do something with the manifest } // Call the correct code depending on the available version val version = getAndroidGradlePluginVersion(project) when { version < VersionNumber.parse("4.1.0") -> error("Unsupported AGP version") version < VersionNumber.parse("4.2.0") -> handle4Dot1(project, callback) version < VersionNumber.parse("7.0.0") -> handle4Dot2(project, callback) else -> handle7Dot0(project, callback) } compileOnly("com.android.tools.build:gradle:4.1.0")
75. 3. Compile against multiple versions src/ │ ├─ main/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ ├─ debug/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ └─ release/ ├─ AndroidManifest.xml └─ kotlin/.../
76. 3. Compile against multiple versions src/ │ ├─ main/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ ├─ debug/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ └─ release/ ├─ AndroidManifest.xml └─ kotlin/.../
77. 3. Compile against multiple versions src/ │ ├─ main/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ ├─ debug/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ └─ release/ ├─ AndroidManifest.xml └─ kotlin/.../
78. 3. Compile against multiple versions src/ │ ├─ main/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ ├─ debug/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ └─ release/ ├─ AndroidManifest.xml └─ kotlin/.../ src/ │ ├─ main/kotlin/.../ │ └─ SamplePlugin.kt │ ├─ compat4Dot1/kotlin/.../ │ └─ Compat4Dot1.kt │ ├─ compat4Dot2/kotlin/.../ │ └─ Compat4Dot2.kt │ └─ compat7Dot0/kotlin/.../ └─ Compat7Dot0.kt
79. 3. Compile against multiple versions src/ │ ├─ main/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ ├─ debug/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ └─ release/ ├─ AndroidManifest.xml └─ kotlin/.../ src/ │ ├─ main/kotlin/.../ │ └─ SamplePlugin.kt │ ├─ compat4Dot1/kotlin/.../ │ └─ Compat4Dot1.kt │ ├─ compat4Dot2/kotlin/.../ │ └─ Compat4Dot2.kt │ └─ compat7Dot0/kotlin/.../ └─ Compat7Dot0.kt
80. 3. Compile against multiple versions src/ │ ├─ main/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ ├─ debug/ │ ├─ AndroidManifest.xml │ └─ kotlin/.../ │ └─ release/ ├─ AndroidManifest.xml └─ kotlin/.../ src/ │ ├─ main/kotlin/.../ │ └─ SamplePlugin.kt │ ├─ compat4Dot1/kotlin/.../ │ └─ Compat4Dot1.kt │ ├─ compat4Dot2/kotlin/.../ │ └─ Compat4Dot2.kt │ └─ compat7Dot0/kotlin/.../ └─ Compat7Dot0.kt
81. 3. Compile against multiple versions // Compatibility code in src/compat4Dot1/kotlin/Compat4Dot1.kt fun handle4Dot1(project: Project, callback: Action<Provider<RegularFile>>) { val extension = project.extensions.getByType(ApplicationExtension::class.java) extension.onVariantProperties { variant -> val manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) callback.execute(manifest) } } // Compatibility code in src/compat4Dot2/kotlin/Compat4Dot2.kt fun handle4Dot2(project: Project, callback: Action<Provider<RegularFile>>) { ... } // Compatibility code in src/compat7Dot0/kotlin/Compat7Dot0.kt fun handle7Dot0(project: Project, callback: Action<Provider<RegularFile>>) { ... }
82. 3. Compile against multiple versions // Compatibility code in src/compat4Dot1/kotlin/Compat4Dot1.kt fun handle4Dot1(project: Project, callback: Action<Provider<RegularFile>>) { val extension = project.extensions.getByType(ApplicationExtension::class.java) extension.onVariantProperties { variant -> val manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) callback.execute(manifest) } } // Compatibility code in src/compat4Dot2/kotlin/Compat4Dot2.kt fun handle4Dot2(project: Project, callback: Action<Provider<RegularFile>>) { ... } // Compatibility code in src/compat7Dot0/kotlin/Compat7Dot0.kt fun handle7Dot0(project: Project, callback: Action<Provider<RegularFile>>) { ... }
83. 3. Compile against multiple versions // Compatibility code in src/compat4Dot1/kotlin/Compat4Dot1.kt fun handle4Dot1(project: Project, callback: Action<Provider<RegularFile>>) { val extension = project.extensions.getByType(ApplicationExtension::class.java) extension.onVariantProperties { variant -> val manifest = variant.artifacts.get(ArtifactType.MERGED_MANIFEST) callback.execute(manifest) } } // Compatibility code in src/compat4Dot2/kotlin/Compat4Dot2.kt fun handle4Dot2(project: Project, callback: Action<Provider<RegularFile>>) { ... } // Compatibility code in src/compat7Dot0/kotlin/Compat7Dot0.kt fun handle7Dot0(project: Project, callback: Action<Provider<RegularFile>>) { ... }
84. 3. Compile against multiple versions // In your build.gradle.kts val compat4Dot1 by sourceSets.creating val compat4Dot2 by sourceSets.creating val compat7Dot0 by sourceSets.creating dependencies { compat4Dot1.compileOnlyConfigurationName("com.android.tools.build:gradle:4.1.0") compat4Dot2.compileOnlyConfigurationName("com.android.tools.build:gradle:4.2.0") compat7Dot0.compileOnlyConfigurationName("com.android.tools.build:gradle:7.0.0") ...
85. // In your build.gradle.kts val compat4Dot1 by sourceSets.creating val compat4Dot2 by sourceSets.creating val compat7Dot0 by sourceSets.creating dependencies { compat4Dot1.compileOnlyConfigurationName("com.android.tools.build:gradle:4.1.0") compat4Dot2.compileOnlyConfigurationName("com.android.tools.build:gradle:4.2.0") compat7Dot0.compileOnlyConfigurationName("com.android.tools.build:gradle:7.0.0") ... 3. Compile against multiple versions compat4Dot2 compat4Dot1 compat7Dot0
86. 3. Compile against multiple versions // In your build.gradle.kts val compat4Dot1 by sourceSets.creating val compat4Dot2 by sourceSets.creating val compat7Dot0 by sourceSets.creating dependencies { compat4Dot1.compileOnlyConfigurationName("com.android.tools.build:gradle:4.1.0") compat4Dot2.compileOnlyConfigurationName("com.android.tools.build:gradle:4.2.0") compat7Dot0.compileOnlyConfigurationName("com.android.tools.build:gradle:7.0.0") ... compat4Dot2 compat4Dot1 compat7Dot0 AGP 4.2.0 AGP 4.1.0 AGP 7.0.0
87. 3. Compile against multiple versions ... compileOnly(compat4Dot1.output) compileOnly(compat4Dot2.output) compileOnly(compat7Dot0.output) } tasks.withType<Jar> { from(compat4Dot1.output) from(compat4Dot2.output) from(compat7Dot0.output) } compat4Dot2 compat4Dot1 compat7Dot0 AGP 4.2.0 AGP 4.1.0 AGP 7.0.0 main
88. ... compileOnly(compat4Dot1.output) compileOnly(compat4Dot2.output) compileOnly(compat7Dot0.output) } tasks.withType<Jar> { from(compat4Dot1.output) from(compat4Dot2.output) from(compat7Dot0.output) } com.droidcon.sample 3. Compile against multiple versions compat4Dot2 compat4Dot1 compat7Dot0 AGP 4.2.0 AGP 4.1.0 AGP 7.0.0 main
89. 3. Compile against multiple versions // Main code in src/main/kotlin/SamplePlugin.kt val version = getAndroidGradlePluginVersion(project) when { version < VersionNumber.parse("4.1.0") -> error("Unsupported AGP version") version < VersionNumber.parse("4.2.0") -> handle4Dot1(project, callback) version < VersionNumber.parse("7.0.0") -> handle4Dot2(project, callback) else -> handle7Dot0(project, callback) }
90. Does it work now? id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } } id("com.android.application") version "4.2.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { minifyEnabled(true) } } }
91. Does it work now? id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } } id("com.android.application") version "4.2.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { minifyEnabled(true) } } } > ./gradlew printReleaseManifest > > <?xml version="1.0" encoding="utf-8"?> > <manifest xmlns:android="...">
92. Does it work now? id("com.android.application") version "7.0.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { isMinifyEnabled = true } } } id("com.android.application") version "4.2.0" id("com.droidcon.sample") version "1.0.0" android { buildTypes { named("release").configure { minifyEnabled(true) } } } > ./gradlew printReleaseManifest > > <?xml version="1.0" encoding="utf-8"?> > <manifest xmlns:android="..."> > ./gradlew printReleaseManifest > > <?xml version="1.0" encoding="utf-8"?> > <manifest xmlns:android="...">
93. Non-plugin dependencies
94. Non-plugin dependencies your plugin dependency 1.2.0
95. Non-plugin dependencies your plugin dependency 1.2.0 1.1.0 dependency another plugin
96. Non-plugin dependencies your plugin dependency 1.2.0 1.1.0 dependency another plugin project
97. Non-plugin dependencies your plugin dependency 1.2.0 1.1.0 dependency another plugin project
98. Embedding dependencies Declaring dependencies your plugin dependency
99. Embedding dependencies Declaring dependencies Embedding dependencies your plugin dependency your plugin dependency
100. Embedding dependencies Declaring dependencies Embedding dependencies Also repackage classes: foo.Dependency -> plugin.foo.Dependency foo.bar.Other -> plugin.foo.bar.Other your plugin dependency your plugin dependency
101. Embedding dependencies Declaring dependencies Embedding dependencies Also repackage classes: foo.Dependency -> plugin.foo.Dependency foo.bar.Other -> plugin.foo.bar.Other your plugin dependency See https://github.com/johnrengelman/shadow or https://github.com/GradleUp/gr8 for more details your plugin dependency
102. Testing
103. Testing against multiple versions # Example CI config for GitHub Actions jobs: verify: strategy: matrix: android-gradle-plugin: [ 4.1.0, 4.2.0, 7.0.0 ] steps: # ... - name: 'Run checks' env: ANDROID_GRADLE_PLUGIN_VERSION: ${{ matrix.android-gradle-plugin }} run: ./gradlew check --stacktrace # ... See https://docs.gradle.org/current/userguide/testing_gradle_plugins.html for more details
104. Testing against multiple versions # Example CI config for GitHub Actions jobs: verify: strategy: matrix: android-gradle-plugin: [ 4.1.0, 4.2.0, 7.0.0 ] steps: # ... - name: 'Run checks' env: ANDROID_GRADLE_PLUGIN_VERSION: ${{ matrix.android-gradle-plugin }} run: ./gradlew check --stacktrace # ... See https://docs.gradle.org/current/userguide/testing_gradle_plugins.html for more details
105. Testing against multiple versions # Example CI config for GitHub Actions jobs: verify: strategy: matrix: android-gradle-plugin: [ 4.1.0, 4.2.0, 7.0.0 ] steps: # ... - name: 'Run checks' env: ANDROID_GRADLE_PLUGIN_VERSION: ${{ matrix.android-gradle-plugin }} run: ./gradlew check --stacktrace # ... See https://docs.gradle.org/current/userguide/testing_gradle_plugins.html for more details
106. Testing against multiple versions See https://docs.gradle.org/current/userguide/testing_gradle_plugins.html for more details
107. What did we talk about? • Backwards compatibility
108. What did we talk about? • Backwards compatibility • Why it can be a problem
109. What did we talk about? • Backwards compatibility • Why it can be a problem • Determining the AGP version ◦ Fields from AGP ◦ Gradle APIs
110. What did we talk about? • Backwards compatibility • Why it can be a problem • Determining the AGP version ◦ Fields from AGP ◦ Gradle APIs • Writing compatible code ◦ Reflection ◦ Groovy ◦ Compiling against multiple versions
111. What did we talk about? • Backwards compatibility • Why it can be a problem • Determining the AGP version ◦ Fields from AGP ◦ Gradle APIs • Writing compatible code ◦ Reflection ◦ Groovy ◦ Compiling against multiple versions • Non-plugin dependencies
112. What did we talk about? • Backwards compatibility • Why it can be a problem • Determining the AGP version ◦ Fields from AGP ◦ Gradle APIs • Writing compatible code ◦ Reflection ◦ Groovy ◦ Compiling against multiple versions • Non-plugin dependencies • Testing
113. What did we talk about? • Backwards compatibility • Why it can be a problem • Determining the AGP version ◦ Fields from AGP ◦ Gradle APIs • Writing compatible code ◦ Reflection ◦ Groovy ◦ Compiling against multiple versions • Non-plugin dependencies • Testing See https://github.com/simonschiller/manifestprinter for a sample project
114. Writing backwards compatible Gradle plugins Simon Schiller • droidcon Berlin 2022 simonxschiller simonschiller simonschiller.io