Create a Github library mix of jvm and Kotlin multiplatform - kotlin

Question

I am trying to build an Android Library and I have the following:
Github Repo for the library
Library 1: Kotlin native/multiplatform code that can compile to Android and iOS
Library 2: Kotlin/JVM code dependent on Library 1
Example App: App using Library 2 and Library 1
Personal Android Project
Dependent on the Github Library above
On my personal project I only have:
implementation 'com.github.username:myrepo:0.5'
Issues
The private Android project is loading android library (Library 2) but the multiplatform kotlin models and functions (Library 1) are not accessible.
Note that the example app of the library is working fine. I suspect that the jitpack.io is not publishing the artifacts correctly. Any idea on how to troubleshoot this? Is there anything that should be done to the gradle files to solve the problem?
I would like to have the multiplatform library published alone. I tried to access it from a multiplatform Kotlin module but I am getting "Unable to resolve dependencies". This is what I was trying:
implementation 'com.github.username.myrepo:library1_moduleName:0.1'
Gradle for Library 1 multiplatform:
plugins {
kotlin("multiplatform")
}
kotlin {
//select iOS target platform depending on the Xcode environment variables
val iOSTarget: (String, KotlinNativeTarget.() -> Unit) -> KotlinNativeTarget =
if (System.getenv("SDK_NAME")?.startsWith("iphoneos") == true)
::iosArm64
else
::iosX64
iOSTarget("ios") {
binaries {
framework {
baseName = "library1"
freeCompilerArgs.add("-Xobjc-generics")
}
}
}
jvm("android")
sourceSets["commonMain"].dependencies {
implementation("org.jetbrains.kotlin:kotlin-stdlib-common")
}
sourceSets["androidMain"].dependencies {
implementation("org.jetbrains.kotlin:kotlin-stdlib")
}
}
val packForXcode by tasks.creating(Sync::class) {
val targetDir = File(buildDir, "xcode-frameworks")
/// selecting the right configuration for the iOS
/// framework depending on the environment
/// variables set by Xcode build
val mode = System.getenv("CONFIGURATION") ?: "DEBUG"
val framework = kotlin.targets
.getByName<KotlinNativeTarget>("ios")
.binaries.getFramework(mode)
inputs.property("mode", mode)
dependsOn(framework.linkTask)
from({ framework.outputDirectory })
into(targetDir)
/// generate a helpful ./gradlew wrapper with embedded Java path
doLast {
val gradlew = File(targetDir, "gradlew")
gradlew.writeText(
"#!/bin/bash\n"
+ "export 'JAVA_HOME=${System.getProperty("java.home")}'\n"
+ "cd '${rootProject.rootDir}'\n"
+ "./gradlew \$#\n"
)
gradlew.setExecutable(true)
}
}
tasks.getByName("build").dependsOn(packForXcode)
Gradle for library 2
apply plugin: 'com.android.library'
apply plugin: 'kotlin-android'
apply plugin: 'kotlin-android-extensions'
android {
repositories {
google()
jcenter()
maven { url 'https://jitpack.io' }
}
compileSdkVersion 29
buildToolsVersion "29.0.0"
defaultConfig {
minSdkVersion 19
targetSdkVersion 29
testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
consumerProguardFiles 'consumer-rules.pro'
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
}
dependencies {
implementation fileTree(dir: 'libs', include: ['*.jar'])
implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
api project(":library1")
}

Answer 1

I suggest you change your build.gradle configuration for targeting android/ Change it to
plugins {
kotlin("multiplatform")
id("com.android.library")
id("maven-publish")
}
android {
compileSdkVersion 29
buildToolsVersion "29.0.0"
defaultConfig {
minSdkVersion 19
targetSdkVersion 29
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
}
}
}
kotlin {
//select iOS target platform depending on the Xcode environment variables
val iOSTarget: (String, KotlinNativeTarget.() -> Unit) -> KotlinNativeTarget =
if (System.getenv("SDK_NAME")?.startsWith("iphoneos") == true)
::iosArm64
else
::iosX64
iOSTarget("ios") {
binaries {
framework {
baseName = "library1"
freeCompilerArgs.add("-Xobjc-generics")
}
}
}
// jvm("android")
android {
publishLibraryVariants("release")
}
sourceSets["commonMain"].dependencies {
implementation("org.jetbrains.kotlin:kotlin-stdlib-common")
}
sourceSets["androidMain"].dependencies {
implementation("org.jetbrains.kotlin:kotlin-stdlib")
}
}
val packForXcode by tasks.creating(Sync::class) {
val targetDir = File(buildDir, "xcode-frameworks")
/// selecting the right configuration for the iOS
/// framework depending on the environment
/// variables set by Xcode build
val mode = System.getenv("CONFIGURATION") ?: "DEBUG"
val framework = kotlin.targets
.getByName<KotlinNativeTarget>("ios")
.binaries.getFramework(mode)
inputs.property("mode", mode)
dependsOn(framework.linkTask)
from({ framework.outputDirectory })
into(targetDir)
/// generate a helpful ./gradlew wrapper with embedded Java path
doLast {
val gradlew = File(targetDir, "gradlew")
gradlew.writeText(
"#!/bin/bash\n"
+ "export 'JAVA_HOME=${System.getProperty("java.home")}'\n"
+ "cd '${rootProject.rootDir}'\n"
+ "./gradlew \$#\n"
)
gradlew.setExecutable(true)
}
}
tasks.getByName("build").dependsOn(packForXcode)
create an AndroidManifest.xml file for library1 under src/main/AndroidManifest.xml
<manifest package="library1"/>
you can now push your projet to github, create a tag and wait for jitpack to do its magic
When you want to use it in library2, under the dependencies section, just add
implementation 'com.github.username.myrepo:library1-android:0.1' //for android

Answer 2

Think you may need to enable meta-data for the multi-platform library; in settings.gradle:
enableFeaturePreview('GRADLE_METADATA')
As well as configuring the library for Maven (it is unclear how you publish it to GitHub, as the build.gradle does not feature any of that as automation). Even when publishing it to GitHub instead of mavenLocal(), it likely needs to provide some kind of meta-data... as "Unable to resolve dependencies" might hint for, assuming that it exists under the referenced package name.
apply plugin: 'maven-publish'
group 'com.github.username'
version '1.0.0'
Configuration api is merely good for dependencies, which are being referenced by multiple modules; everything else (any single occurance) should be implementation. I mean, I find the library 2 build.gradle confusing, because on top it reads maven { url 'https://jitpack.io' } (without actually referencing a remote dependency) and then later it reads api project(":library1") (which defintely is a local dependency).