Enables seamless integration between shared code and Flutter, generating necessary Dart files and Android module classes using KSP, while supporting JSON serialization with `json_serializable`.
Add the KSP gradle plugin to your multiplatform project's build.gradle.kts file, if you have subprojects, add it to the subproject's build.gradle.kts file.
// android/shared/build.gradle.kts
plugins {
// from gradlePluginPortal()
id("com.google.devtools.ksp") version "1.9.23-1.0.20"
}
Then add the flutter-kmp to the commonMain source set dependencies. Also add the generated common source set to the commonMain source set:
// android/shared/build.gradle.kts
val commonMain by getting {
kotlin.srcDir("build/generated/ksp/metadata/commonMain/kotlin")
dependencies {
// ...
implementation("de.voize:flutter-kmp:<version>")
}
}
Add flutter-kmp-stubs as compileOnly dependency to the androidMain source set:
// android/shared/build.gradle.kts
val androidMain by getting {
dependencies {
// ...
compileOnly("de.voize:flutter-kmp-stubs:<version>")
}
}
Then add flutter-kmp-ksp to the KSP configurations:
// android/shared/build.gradle.kts
dependencies {
add("kspCommonMainMetadata", "de.voize:flutter-kmp-ksp:<version>")
add("kspAndroid", "de.voize:flutter-kmp-ksp:<version>")
add("kspIosX64", "de.voize:flutter-kmp-ksp:<version>")
add("kspIosArm64", "de.voize:flutter-kmp-ksp:<version>")
// (if needed) add("kspIosSimulatorArm64", "de.voize:flutter-kmp-ksp:<version>")
}
Configure the KSP task dependencies and copy the generated Dart files to your flutter plugin:
// android/shared/build.gradle.kts
tasks.withType<org.jetbrains.kotlin.gradle.dsl.KotlinCompile<*>>().configureEach {
if(name != "kspCommonMainKotlinMetadata") {
dependsOn("kspCommonMainKotlinMetadata")
} else {
finalizedBy("copyGeneratedDartFiles")
}
}
tasks.register<Copy>("copyGeneratedDartFiles") {
dependsOn("kspCommonMainKotlinMetadata")
from("build/generated/ksp/metadata/commonMain/resources/flutterkmp")
into("path/to/flutter/lib/generated")
}
Register the generated Android module classes (ending with ...Android.kt) in your Flutter plugin Android class:
class MyFlutterPlugin: FlutterPlugin {
override fun onAttachedToEngine(flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
MyFlutterModuleAndroid()
// ...
}
...
}
The generated Dart code uses the json_serializable package.
Add the following dependencies to your Flutter plugin:
flutter pub add json_annotation dev:build_runner dev:json_serializable
Then after generating Dart data classes make sure to the following command to generate the serialization code:
dart run build_runner build --delete-conflicting-outputs
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