Hello! Was anyone able to share ViewModels/Presenters between Android and iOS? I've been trying for a while but can't seem to get a solution. Here's my setup so far.

class MyViewModel(private val useCase: UseCase) : ViewModel() {
    fun doSomething() {
        useCase()
        liveData.value = "New Value"
    }
}

class MyPresenter(private val myView: MyView, private val useCase: UseCase) : BasePresenter() {
    fun doSomething() {
        useCase()
        myView.updateView("New Value")
    }
}

I wanted to extract the common code between them so initially, I created an expected class and wanted something like this:

expect class MyCommonClient(useCase: UseCase) {
    fun doSomething() {
        useCase()
        success("New Value")
    }
    
    expect fun success(newValue: String)  
}

But then,

Expected declaration must not have a body

So I tried out a class:

abstract class MyCommonClient(useCase: UseCase) {
    fun doSomething() {
        useCase()
        success("New Value")
    }
    
    abstract fun success(newValue: String)  
}

But now, I'm having multiple supertypes

class MyViewModel : ViewModel(), MyCommonClient() <--- Error

Am I running towards a wall or is there any workaround or pattern to achieve something like this? Thanks in advance!

Hi 🙂 I’ve finished the Kotlin Hands-on “Targeting iOS and Android with Kotlin Multiplatform” -> https://play.kotlinlang.org/hands-on/Targeting%20iOS%20and%20Android%20with%20Kotlin%20Multiplatform/01_Introduction 🎉 🤪 Now I want to look at using multiplatform libraries like the ktor-http-client https://ktor.io/clients/index.html. Do anyone knows some other good hands-on labs for that? 🙏

Hi all, I'm participating in Advent of Code (https://adventofcode.com/2019) this year again, and just like last year, I'm trying to write my solutions in Kotlin common code, compile to bytecode, JS and native (MinGW), and do some rudimentary performance comparisons. Now, for today's puzzle I have added coroutines, and suddenly my MPP project fails to build. I have fiddled with absolutely everything - kotlin plugin version, gradle version, JDK version, library versions, in every permutation I could think off, but my build keeps failing with the completely unhelpful

Execution failed for task ':linkDebugExecutableMingw'.
> Process 'command 'C:\dev\java\openjdk-11.0.2\bin\java.exe'' finished with non-zero exit value 1

Before I throw in the towel and just continue on JVM alone, if anyone would be willing to take a look to see what I could be doing wrong it would be much appreciated. The repo is https://github.com/jorispz/aoc-2019, the project is pretty much standard as generated by IDEA, with the addition of the coroutine depenendencies.

I’m working out a multiplatform library design right now where I would like objects to reference to each other in cycles. Would that cause problems (like leaks) on any of the supported platforms?

Hi guys! I already implemented coroutine for jdk8 in my common dependencies. But i can't seem to use

GlobalScope.future

P.S. Im developing a library for android and iOS

I’m trying to use

@Parcelize

in a multiplatform library, using `expect`/`actual` on

@Parcelize

and

Parcelable

, but I encounter a very weird error when using the

kotlin.android.extensions

plugin on one library: “This class does not have a constructor” on a

data class

. Anyone encountered this?

I would appreciate some help. Repo: https://github.com/bdudelsack/kotlin-fullstack-example

1. we use rxjava in our code, is there a suitable replacement? Is the current version of flow MPP-compatible?

2. What about iOS? How to include them? Any advice?

Hello guys, I have a question: I want to compile my commonMain and iosMain kotlin code into a static library, I achieve this target with gradle plugin, but my problem is, I don't know how to implement an abstract kotlin class in Objective-C and pass it to kotlin, because when I compile kotlin code to static library, all stuff are C struct. Here is my kotlin abstract class:

abstract class ConfEvents {
  open fun onPeerJoined(uid: String) {}
}

Here is the generated C header:

struct {
  libAvConf_KType* (*_type)(void);
  libAvConf_kref_com_piasy_avconf_ConfEvents (*ConfEvents)();
  void (*onPeerJoined)(libAvConf_kref_com_piasy_avconf_ConfEvents thiz, const char* uid);     
} ConfEvents;

If I compile kotlin code into framework, then

ConfEvents

would have a Objective-C interface, then I can extend it and pass it to kotlin.

How can I add a special extension to a class only for Android? In iOS, this worked:

fun MyType.newMethod(x: NSSomething) {}

I could call it from iOS with the appropriate type. But if I add the equivalent in Android, it isn’t callable.

I try to move data2viz to the “new” MPP plugin. We are currently targetting JS, JavaFx and Android. I don’t find any example of a project with the new MPP plugin that does this. Is it possible? Does anyone has a project that I could use as an example?

Hi guys, i have this function inside my kotlin shared library.

suspend fun fetchUsers(): List<String> {
        val response = client.get<JsonObject> { url("$baseUrl/heartbeat.json") }
        val userIds = response.keys.toList()
        return userIds
    }

Now im trying to implement it in a pure old java project. I enabled the kotlin plugin in this project and created this function:

fun fetchUsersFromKtLib(): List<String> {
    val api = HeartbeatApi()
    val users = GlobalScope.future { api.fetchUsers()  }
    return users.get()
}

Now everytime im calling this

fetchUsersFromKtLib

function, there is a jank in my UI (a freeze). Im trying to solve this problem for about 3 days now. So far this is the cleanest way i called the function from the kotlin shared library. What can you suggest to avoid any UI freeze? Thanks guys!

Hi! I have started a new mp project in IDEA (kotlin version 1.3.61) and added dependency for coroutines (

1.3.2

) and implemented an iOS dispatcher as explained by @salomonbrys in the kotlinconf workshop. The

actual

on the android side works fine, but I get an unresolved reference on the

CoroutineDispatcher

import on the ios side. When running the gradle assemble i get an error saying

The abi versions don't match. Expected '[17]', found '14'

. Any idea what causes this and how to resolve it?

Hey, I'm looking for ktor setup example for ios

Hi everyone, I'm working on a native Android Library (aar) to make available to the Android UI team, who doesn't have access to the source code. I want to use a Kotlin multiplatform generated aar inside this library. I had followed the steps to add the main android library to an android app (to simulate what the UI team will have to do) as described here - https://developer.android.com/studio/projects/android-library, and it worked fine when it was just the main library. I then added the mpp generated aar to the main android library, following the same steps (https://developer.android.com/studio/projects/android-library) but the public classes aren't visible. I tried doing the same but using non-mpp libraries (aar), and I can at least see the nested libraries classes from the top level lib.

app
	|
	|_ LibA 
			|
			|_ LibB (mpp)

Next thing I have in mind is trying to generate .jar libraries from Kotlin mpp and see if that works Any ideas would be highly appreciated.

Replacing

iosX64("ios")

with

targetFromPreset(presets.iosX64, 'ios')

is resulting in a strange error that I can't figure out. I'm already using Xcode 11 (currently downloading 11.3 if that changes anything). Does this look familiar to anyone?

> Task :shared:linkDebugFrameworkIos
error: Invalid record (Producer: 'LLVM8.0.0svn' Reader: 'LLVM APPLE_1_1100.0.33.8_0')
1 error generated.
e: Compilation failed: The /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ command returned non-zero exit code: 1.
output:

 * Source files:
 * Compiler version info: Konan: 1.3.60 / Kotlin: 1.3.60
 * Output kind: FRAMEWORK

e: org.jetbrains.kotlin.konan.KonanExternalToolFailure: The /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ command returned non-zero exit code: 1.

Uh… I think I got confused with something while juggling many different kind of changes. Replacing

iosX64()

with

fromPreset(presets.iosX64)

is fine, but the actual error is coming from these lines:

framework {
  // Disable bitcode embedding for the simulator build.
  if (!buildForDevice) {
    embedBitcode("disable")
  }
}

cc @ilya.matveev

Hello, is there a way in Kotlin to use property delegates for data classes in constructor? I want to create something like Swift's

Property Wrapper

https://docs.swift.org/swift-book/LanguageGuide/Properties.html#ID617

Does anyone know if there's a list matching ABI version code to version numbers? Kinda hard to figure out " The abi versions don't match. Expected '[17]', found '9'" otherwise 😄

Anyone targeting watchOS and tvOS along with iOS in one project? I can't find any reference projects to do that. 1.3.6 is supposed to support all of them but there is not a single sample project on how to configure the build 😥

Any way to solve this incompatibility issues of java and kotlin?

We have published a new article "Continuous delivery for your Kotlin Multiplatform library": https://badootech.badoo.com/continuous-delivery-for-your-kotlin-multiplatform-library-3ab5ad5cba59

Kotlin does not have certain interfaces & classes, like Queue, LinkedList ( because on JVM it uses Java's implementations ), but I'm wondering if there's a place were these are (to be?) defined? e.g. is there a standard, common Queue interface to be used by MP?

Any good examples of a multiplatform project that inteops with jni on the android side? Essentially looking for multiplatform talking to shared c/c++

Hi All, I am trying to use mt coroutines in my project but cannot resolve

newSingleThreadContext

in iosMain • I have built https://github.com/Kotlin/kotlinx.coroutines/tree/native-mt and installed it locally • added

kotlin.mpp.enableGranularSourceSetsMetadata=true

to gradle.properties • commonMain depends on

implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core-common:1.3.2-native-mt-SNAPSHOT"

• iosMain depends on

implementation "org.jetbrains.kotlinx:kotlinx-coroutines-core-native:1.3.2-native-mt-SNAPSHOT"

• using kotlin 1.3.61 Am I missing something? P.S. I have also tried to build https://github.com/kpgalligan/MTCoroutines locally and it worked.

Interesting developments in cross-platform UI workflow: This app can import a design from Sketch and generate UI code for Android (paid), iOS (paid) and Flutter (free) https://supernova.io/pricing It would be awesome if Kotlin Multiplatform common code could easily connect to such native UIs as are generated by supernova. This would level the playing field in sone regards vd Flutter, with the benefits of Kotlin and of being native. Also, Adobe XD will support Flutter code generation (for free, due to Google support) in “early 2020”. https://theblog.adobe.com/xd-flutter-plugin-generate-dart-code-design-elements/

Looks like ktor http client is not available for watchOS? Is that correct or I am just missing something?

Hey guys, stuck at this issue for a day. Any solution?

Task sharedlinkSharedDebugFrameworkIos

e: Compilation failed: Expected 'BaseContinuationImpl.invokeSuspend' but was 'org.jetbrains.kotlin.ir.declarations.impl.IrFunctionImpl@1f36969b' * Source files: * Compiler version info: Konan: 1.3.61 / Kotlin: 1.3.60 * Output kind: FRAMEWORK e: java.lang.AssertionError: Expected 'BaseContinuationImpl.invokeSuspend' but was 'org.jetbrains.kotlin.ir.declarations.impl.IrFunctionImpl@1f36969b' at org.jetbrains.kotlin.backend.konan.llvm.CodeGeneratorVisitor.getContinuation(IrToBitcode.kt:1936) at org.jetbrains.kotlin.backend.konan.llvm.CodeGeneratorVisitor.evaluateFunctionCall(IrToBitcode.kt:2055) at org.jetbrains.kotlin.backend.konan.llvm.CodeGeneratorVisitor.evaluateCall(IrToBitcode.kt:1795) at org.jetbrains.kotlin.backend.konan.llvm.CodeGeneratorVisitor.evaluateExpression(IrToBitcode.kt:784) ...