Hey people! Is there any way to make of a pure Kotlin module multiplatform?

Is there any sane way to let ios implement a suspending interface? When we have an interface that suspends:

public fun runTest(suspending: SuspendingInterface) {
  CoroutineScope(Dispatchers.Default).launch {
    println(suspending.value())
  }
}

public interface SuspendingInterface {

  public suspend fun value(): Int
}

And ios switches threads:

class SuspendingInterfaceImpl : SuspendingInterface{
  func value(completionHandler: @escaping (KotlinInt?, Error?) -> Void) {
    DispatchQueue.global().async {
      completionHandler(42, nil)
    }
  }
}

CoroutineTest.runTest(SuspendingInterfaceImpl())

That directly fails with:

kotlin.native.IncorrectDereferenceException: illegal attempt to access non-shared kotlinx.coroutines.internal.DispatchedContinuation@1f67dc8 from other thread

[SOLVED] Hi ! I try to convert an ObjC method which uses C functions in Kotlin Native but it does not work 😞 Here is the ObjC / C code :

- (NSString *) getSysInfoByName:(char *)typeSpecifier
{
    size_t size;
    sysctlbyname(typeSpecifier, NULL, &size, NULL, 0);
    
    char *answer = malloc(size);
    sysctlbyname(typeSpecifier, answer, &size, NULL, 0);
    
    NSString *results = [NSString stringWithCString:answer encoding: NSUTF8StringEncoding];

    free(answer);
    return results;
}

And my Kotlin version :

private fun sysInfoByName(identifier: String): String? {
        val size = cValue<size_tVar>()
        sysctlbyname(identifier, null, size, null, 0)

        var result: String? = ""

        memScoped {
            val value = allocArray<charfVar>(size.size)
            sysctlbyname(identifier, value, size, null, 0)

            result = NSString.stringWithCString(cString = value, NSUTF8StringEncoding)
        }

        return result
    }

The result is always empty. 😞 Do you know why ? 😇

Hi there, Currently I have been writing a lot of libraries. And the end users of my libraries a primarily not kotlin users. They are mostly Java. So, my API designs are now so highly considerate when developing API with an intention to provide nice interop. Current Status: When I write my API, all of the kotlin test reside in

commonMain

, and just for clarification, I write a couple of Java test in

jvmTest/java

as well to make my self confident that my Java users won't scream at me Question: Is there a way that I can configure my kotlin multiplafrom library and write javascript (or even better, typescript) test in typescript that consume my kotlin lib? something like

jsTest/javascript

or

jsTest/typescript

? Extended Question: Can that be achieved similar to ObjC? C? say

nativeTest/objectiveC

or

nativeTest/C

Does epect & actual work with interfaces? I want to define a Interface like so:

expect interface Image

expect interface ImageLoader {

    fun loadFullImage(photo: Photo): Image

    fun loadThumbnailImage(photo: Photo): Image

}

And for Android it should load a "ImageBitmap"

actual interface Image // ???

actual interface ImageLoader {

    actual fun loadFullImage(photo: Photo): ImageBitmap

    actual fun loadThumbnailImage(photo: Photo): ImageBitmap

}

And for iOS "Image" should be "UIImage" of course. Is that possible?

Attention all Kotlin Multiplatform users ❗️ Change the future of the technology by sharing your thoughts and feedback in the Kotlin Multiplatform user survey! Special prizes will be raffled after the survey. 🎁 https://surveys.jetbrains.com/s3/Kotlin-Multiplatform-user-survey-July-2021

Hi all, i have this view model delegate on ios side that looks like this

import Foundation

class ViewModelDelegate : ObservableObject {

    @Published var state: State = ViewModelsKt.DEFAULT_STATE
    @Published var command: Command? = nil
    
    init() {
        subscribe(viewModel: ModuleKt.viewModel)
    }
    
    func subscribe(viewModel: ViewModel) {
        viewModel.onChange { (state) in
            self.state = state
        }
    }
}

is it possible to use Combine’s

@Published

from kotlin side and get rid of this delegate all together?

Does anyone have answer on this https://stackoverflow.com/questions/67949522/unable-to-build-kotlin-multiplatform-mobile-project-on-macbook-m1-chip?

hi all, how we can use DI in KMM. I mean automatic DI for ApiServices, UseCases etc ? and ideas ?

Newbie question... I have an existing Android only project and it has an 

app

 module, and then a 

my_composables

 module. I converted the project to support kmm in order to get compose for desktop working. Now 

my_composables

 is a kmm module with

androidMain
commonMain
desktopMain
main

I put a brand new 

HelloWorld

 composable in common, and can now use that common composable in my 

app

 module and 

desktopApp

 module. All is good with the world AND I can slowly migrate my android only composables from 

main

 into 

commonMain

 . That's my current strategy. Slowly migrate from 

main

 into 

commonMain

 . Is that "bad" or wrong? Should I just shove everything into 

androidMain

 ? Basically asking "is 

main

 in a kmm module a bad pattern?"

I got error when import this librery

implementation("com.arkivanov.decompose:extensions-compose-jetbrains:0.2.6")

Any help ?

Hi ! Gradle newbie question here. I’ve got a KMM project which uses

kotlinx.serialization

, and targets both Kotlin/JS and Kotlin/JVM (with a Compose for Desktop client). Compose for Desktop requires using Kotlin 1.5.10, but there’s a bugfix in

kotlinx.serialization

for Kotlin 1.5.20 which I need for my Kotlin/JS target. Would there a way for me to fix my Gradle project and satisfy these two requirements ? (code in 🧵)

I have a KMM project which I just updated to kotlin 1.5.20. All works fine, but Android Studio still thinks that my common module depends on 1.4.32. When I build with Gradle all seems to be correctly using version 1.5.20, I get warnings that I expect to get etc. But when I open the file with 1.5.20 warning Studio doesn’t highlight it and looks like it links edited file to 1.4.32. Any hints? TIA

I try to publish a multiplatform project to maven local but I get

Unresolved reference: JvmInline

at

compileKotlinMetadata

phrase.

compileKotlinJvm

works fine.

I’m banging my head over this for the past couple hours. Has anyone else run into this error while trying to build any native target?

> Task :common:linkDebugTestMacOS FAILED
e: Compilation failed: Deserializer for declaration public kotlinx.coroutines/cancel|8411479413341223858[0] is not found

 * Source files:
 * Compiler version info: Konan: 1.5.10 / Kotlin: 1.5.10
 * Output kind: STATIC_CACHE

e: java.lang.IllegalStateException: Deserializer for declaration public kotlinx.coroutines/cancel|8411479413341223858[0] is not found

I’m already forcing all transitive dependencies of coroutines to

1.5.0-native-mt

by using:

implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.0-native-mt") {
  version { strictly("1.5.0-native-mt) }
}

hi I am experiencing

EXC_BAD_ACCESS

when calling some use case. We are using clean arch and everything from domain layer is written in kotlin. We are manually freezing use case objects exposed to iOS. I noticed this in log

/Users/teamcity/buildAgent/work/f01984a9f5203417/runtime/src/main/cpp/Memory.cpp:1581: runtime assert: add ref for reclaimed object

and this is in Xcode:

Thread 47: EXC_BAD_ACCESS (code=1, address=0x4aa017e2280)

Every use case have a callback and the only difference with other calls to common (kotlin) code is that in this situation I am calling another use case from that callback… not sure if that can be a root cause of this issue… Really appreciate if someone can help me how to figure out why is this happening and how to resolve it. Thx in advance

I updated to macOS Monterey (12) Beta and now my Compose for Desktop application is blurry. It worked fine with macOS Big Sur (11). Did someone else have this problem?

Are we able to use IsolateState from the stately library to wrap a nullable value? (edited)

I'm struggling with my first project on KMP. I creat a project simple from KMP plugin in IntilijIdea. Creating all the necessary module for me: Android, Desktop and web. After trying hard I succeeded in making Desktop and Web part compile The problem is with Android part it doesn't compile. And finally I created KMM project using Android Studio It works correctly but I failed to add it with the desktop and web project What I have to do ?! Is there any willing from Jetbrain team to improve the user experience with the plugin and the default project sample ?! 😢 ... By the way, I'm just a student have prior knowledge with Android (Kotlin/Java) But I have to make a website and Android App to my school So I think Kotlin multiplatform is the best choice as I master Kotlin ... So I'm asking if any one can help me in the gradle files And also if my choice of KMP is right ?! Or I have to pick another technology like Flutter/ React native instead

Is compose available on KMM?

Hi Everyone, I have a question about sharing viewmodels. We have quite big project - around 60-70 screens and a lot of features (offline mode, using camera, recording audio, billing, synchronization between server and other devices etc).In general I would say that it is typical client but quite massive. In some point we decided to rewrite it fully using kmm(Android + iOS). So after some research we rewrote one module with kmm and it worked fine - we even shared viewmodels in our prototype. But it is a small module for 5 screens.My question is rather a search for advice. Has anyone had experience writing a large project with kmm and shared viewmodels? Maybe someone has faced some specific issues while sharing viewmodels. On what put more attention? Probably viewmodels are not yet ready to be shared or it not worth it. In general possibility to share viewmodels looks quite appealing. But as this is our first project with kmm and quite big we would like to be sure that it is good idea. Thanks in advance for the reply.

Hello, just stumbled upon this on my github feed: https://github.com/sergeshustoff/dikt

Hi everybody, in our company we are evaluating KMP for sharing business code between our supported platforms: Windows, Mac, Android, iOS (potentially also JS since desktop UI is using it) - in this order of importance. We are deciding between sharing code in C++ library vs. KMP. Have someone already done a comparison? What is the biggest advantage to KMP when compared with C++ solution. Thank you for help.

Hello everybody, Iam developing KMM used by iOS and Android client. I need to use websockets there.Do you have experience with any library which works both for iOS and Android part? Thanks

Hi all, I am working on a KMM library project for android and ios, I have a separate module that contains data classes that are using

Moshi

annotations. I am having compile errors (

Unresolved reference

) when using said data classes inside my KMM library. I've read articles that says it doesn't support other serializing dependencies other than the

kotlinx.serialization

. Is there a way to convert moshi data class into a kotlinx.serialized class inside a KMM project?

Hello, is it possible to have

.dSYM

for static frameworks? I am asking because when ios app crashes with kotlin native library, stack trace does not have anything useful. I have this from the symbolication documentation, but this only works with dynamic frameworks

targets.withType<org.jetbrains.kotlin.gradle.plugin.mpp.KotlinNativeTarget> {
        binaries.all {
            freeCompilerArgs += "-Xadd-light-debug=enable"
        }
    }

I am using sqldelight library with sqlcipher, and if library is static i do not need to link

lsqlcipher

manually, otherwise if library is dynamic i need to link with either

lsqlite3

or

lsqlcipher

, but somehow it does not work and compiler complains that it cannot find

lsqlcipher

. I have added sqlcipher as cocoapod

cocoapods {
        this.ios.deploymentTarget = "13.0"
        // Configure fields required by CocoaPods.
        summary = "Secoris core"
        homepage = "<https://github.com/JetBrains/kotlin>"

        // You can change the name of the produced framework.
        // By default, it is the name of the Gradle project.
        frameworkName = binaryBaseName

        pod("SQLCipher", "~> 4.4")
    }

linking is done like this

targets
       .flatMap { it.compilations }
        .filterIsInstance<org.jetbrains.kotlin.gradle.plugin.mpp.KotlinNativeCompilation>()
        .forEach { compilationUnit ->
            compilationUnit.kotlinOptions.freeCompilerArgs += arrayOf("-linker-options", "-lsqlcipher")
       }

but this gives following error

ld: library not found for -lsqlcipher

. So in conclusion i am able to have encrypted database with sqlcipher if i use static library, with no linking needed, but then there is no

.dSYM

for crash stack traces, or i can have

.dSYM

with dynamic framework, but then sqldelight links to

lsqlite3

and there is no encryption.

Did anybody try move Compose code into multiplatform library? Code works perfect in android application module

plugins {
    id("com.android.application")
    kotlin("android")
}

but when i move it to multiplatform library

plugins {
    kotlin("multiplatform")
    id("com.android.library")
}

compilation fails. Stacktrace in thread.

buildFeatures.compose

enabled,

composeOptions.kotlinCompilerExtensionVersion

set too. What am i do wrong?

I'm upgrading Splitties (a set of multiplatform and Android libraries) to Kotlin 1.5.20 from 1.4.32, and last time I had made a full

build

on my machine (a MacBook Pro) was a long time ago and was very slow, ranging from 15 to 20 minutes… but now! Now, okay, I upgraded the computer a bit in the meantime, but they're in the same ballpark: from Late 2013 MBP with i7 and 16GB of RAM to 2020 MBP 10th gen i5 and 16GB of RAM. So now, it takes about 3 minutes, and I'm super happy, it'll make catching up and adding stuff much easier as I'll have the comfort of local feedback loops and IDE integration. Thank you so much for making the Kotlin/Native compiler faster! 🙏🏼 ❤️

How to fix “modality is different” error?