kotlinlang #multiplatform

root
|___core
     |__src
         |__commonMain
         |__jvmMain //etc
     |__build.gradle.kts
|___otherModule
     |__src
        |__commonMain
        |__jvmMain //ec
     |__ build.gradle.kts
|__settings.gradle.kts //root project name set here
|__gradle.properties

It's defaulting to

core-jvm

core-metadata

etc. right now for the artifact ID, but i'd like all of the generated artifact IDs to be

foo-jvm

foo-metadata

etc. I have been setting them all individually but feel like there might be a better way to just set that parameter once somewhere in the build script.

Shan

11/24/2020, 11:33 PM

Err looks like the separate

metadata

default artifact was removed in Kotlin 1.4.20, but I'm still seeing it when listing out the default publication names.

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publishing {
    publications.withType<MavenPublication>().names // [jvm, kotlinMultiplatform, metadata]
}

Should I just manually set it to not publish the

metadata

artifact, or will it be ignored during the publish task?

➕ 1

BollywoodVillain

11/25/2020, 12:54 PM

Kotlin Multiplatform fails on iOS while calling Ktor suspend functions. The error is

kotlin.native.concurrent.InvalidMutabilityException: mutation attempt of frozen

. It works fine on Android and gets the network data without issues. I created a brand new MPP project using Android Studio MPP template and added the Ktor network code from Ktor-sample/client-mpp repo. What could be the problem? The complete project is on Github at: https://github.com/samkhawase/Kotlin_MPP_Demo. I’m using ktor

1.4.2

, Kotlin

1.4

, Kotlin plugin

1.4.20-release-Studio4.1.1

, and KMM plugin

0.2.0-release-65-Studio4.1

. Here’s a snapshot of my

sourceSets

from

build.gradle.kt

(:shared)

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val ktor_version = "1.4.2"
    sourceSets {
        val commonMain by getting {
            dependencies {
                implementation("org.jetbrains.kotlinx:kotlinx-serialization-json:1.0.1")
                implementation("io.ktor:ktor-client-core:$ktor_version")
                implementation("io.ktor:ktor-client-serialization:$ktor_version")
            }
        }
        val commonTest by getting {
            dependencies {
                //... 
                implementation("io.ktor:ktor-client-core:$ktor_version")
            }
        }
        val androidMain by getting {
            dependencies {
                //... 
                implementation("io.ktor:ktor-client-android:$ktor_version")
                implementation("io.ktor:ktor-client-serialization-jvm:$ktor_version")
            }
        }
        val androidTest by getting {
            dependencies {
                //... 
                implementation("io.ktor:ktor-client-android:$ktor_version")
            }
        }
        val iosMain by getting {
            dependencies {
                implementation("io.ktor:ktor-client-ios:$ktor_version")
                implementation("io.ktor:ktor-client-serialization:$ktor_version")
            }
        }
        val iosTest by getting {
            dependencies {
                implementation("io.ktor:ktor-client-ios:$ktor_version")
                implementation("io.ktor:ktor-client-serialization:$ktor_version")
            }
        }
    }

Here’s the failing Swift code

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func getLocations() {
        let apiService = ApiService()
        apiService.about { (htmlString) in
            print("🦋 htmlString:\n \(htmlString)")
        }
}

struct ContentView: View {
    var body: some View {
        Text(greet()).onAppear {
            print("isMainThread: \(Thread.isMainThread)")
            getLocations()
        }
    }
}

Here’s the complete stacktrace from the iOS app.

BollywoodVillain

11/25/2020, 12:54 PM

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isMainThread: true
Function doesn't have or inherit @Throws annotation and thus exception isn't propagated from Kotlin to Objective-C/Swift as NSError.
It is considered unexpected and unhandled instead. Program will be terminated.
Uncaught Kotlin exception: kotlin.native.concurrent.InvalidMutabilityException: mutation attempt of frozen com.berlin.kmm_demo.shared.ApiService@2a37878
    at 0   shared                              0x0000000100c192dd kfun:kotlin.Throwable#<init>(kotlin.String?){} + 93 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/Throwable.kt:23:37)
    at 1   shared                              0x0000000100c121cb kfun:kotlin.Exception#<init>(kotlin.String?){} + 91 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/Exceptions.kt:23:44)
    at 2   shared                              0x0000000100c1238b kfun:kotlin.RuntimeException#<init>(kotlin.String?){} + 91 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/Exceptions.kt:34:44)
    at 3   shared                              0x0000000100c4793b kfun:kotlin.native.concurrent.InvalidMutabilityException#<init>(kotlin.String){} + 91 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/native/concurrent/Freezing.kt:22:60)
    at 4   shared                              0x0000000100c491f2 ThrowInvalidMutabilityException + 690 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/native/concurrent/Internal.kt:92:11)
    at 5   shared                              0x0000000100d4136c MutationCheck + 108
    at 6   shared                              0x0000000100bb7ce7 kfun:com.berlin.kmm_demo.shared.ApiService#<init>(){} + 455
    at 7   shared                              0x0000000100bbc743 objc2kotlin + 163
    at 8   iosApp                              0x0000000100ae655f $sSo16SharedApiServiceCABycfC + 31
    at 9   iosApp                              0x0000000100ae6467 $s6iosApp12getLocationsyyF + 39 (/Users/skhawase/skunkworks/KMM_Demo/iosApp/iosApp/ContentView.swift:13:1)
    at 10  iosApp                              0x0000000100ae6eaa $s6iosApp11ContentViewV4bodyQrvgyycfU_ + 442 (/Users/skhawase/skunkworks/KMM_Demo/iosApp/iosApp/ContentView.swift:20:9)
    at 11  SwiftUI                             0x00007fff55f13d0c $sIeg_ytIegr_TR + 12
    at 12  SwiftUI                             0x00007fff55e22b01 $sIeg_ytIegr_TRTA + 17
    at 13  SwiftUI                             0x00007fff55f13d2c $sytIegr_Ieg_TR + 12
    at 14  SwiftUI                             0x00007fff55f13d0c $sIeg_ytIegr_TR + 12
    at 15  SwiftUI                             0x00007fff55e22b01 $sIeg_ytIegr_TRTA + 17
    at 16  SwiftUI                             0x00007fff55e22c09 $sIeg_ytIegr_TRTA.8 + 9
    at 17  SwiftUI                             0x00007fff5636e239 $s7SwiftUI16ViewRendererHostPAAE6render8interval17updateDisplayListySd_SbtFyyXEfU_ + 1657
    at 18  SwiftUI                             0x00007fff5636d2f7 $s7SwiftUI16ViewRendererHostPAAE6render8interval17updateDisplayListySd_SbtF + 343
    at 19  SwiftUI                             0x00007fff564d4e41 $s7SwiftUI14_UIHostingViewC14layoutSubviewsyyF + 241
    at 20  SwiftUI                             0x00007fff564d4e65 $s7SwiftUI14_UIHostingViewC14layoutSubviewsyyFTo + 21
    at 21  UIKitCore                           0x00007fff24bcd686 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 2874
    at 22  QuartzCore                          0x00007fff27a5ae67 -[CALayer layoutSublayers] + 258
    at 23  QuartzCore                          0x00007fff27a61319 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 575
    at 24  QuartzCore                          0x00007fff27a6d071 _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 65
    at 25  QuartzCore                          0x00007fff279ad158 _ZN2CA7Context18commit_transactionEPNS_11TransactionEdPd + 496
    at 26  QuartzCore                          0x00007fff279e3ef3 _ZN2CA11Transaction6commitEv + 783
    at 27  UIKitCore                           0x00007fff2468ab96 __34-[UIApplication _firstCommitBlock]_block_invoke_2 + 81
    at 28  CoreFoundation                      0x00007fff203a85db __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
    at 29  CoreFoundation                      0x00007fff203a79ef __CFRunLoopDoBlocks + 434

Process finished with exit code 0

Amritansh

11/25/2020, 10:16 PM

I am getting

Execution failed for task ':shared:cinteropAFNetworkingIosArm64'.> Process 'command '/Applications/Android Studio 2.app/Contents/jre/jdk/Contents/Home/bin/java'' finished with non-zero exit value 1

when I am adding a pod

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cocoapods {
    pod(name ="AFNetworking", version = "~> 4.0.1")
}

Anyone seen this before?

František Hlinka

11/25/2020, 10:54 PM

Hey guys! We’re using the

ios()

target shortcut inside the

kotlin {…}

block in

build.gradle.kts

to create iOS targets for simulator and device and use the same

iosMain

source set. However, the dependencies of the iOS target do not get resolved correctly in the IDE (specifically speaking, the

Platform

object, or SQLDelight’s

NativeSqliteDriver

). If hierarchical project structure is disabled - e.g.

gradle.properties

does not include

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kotlin.mpp.enableGranularSourceSetsMetadata=true
kotlin.native.enableDependencyPropagation=false

, then the project builds anyway even if the IDE can’t resolve the classes. If I add those two lines, the build fails too. This is happening on Kotlin 1.4.10 and 1.4.20. Does anyone know what’s the problem or where should I open an issue? Thanks lots!

Nikolay Kasyanov

11/26/2020, 3:54 PM

Hey folks, I have a feeling this must be a known issue. Here’s what happens: I have a KMP project and as soon as I have built something, IDEA (or Android Studio) starts using built artifacts (jar, class files) for code highlighting and navigation in the editor. For example, it starts falsely reporting some imports as unreachable because of classes being internal (although actual build works flawlessly, meaning internal is just fine). When you cmd-click the import, it shows a decompiled version of it instead of the source code. It definitely happens with types from

commonMain

when imported in files residing in

jvmTest

. Doing

./gradlew clean

solves the problem (editor navigation starts using source code, red highlighting of imports goes away) until next build. IDEA CE 2020.3 beta or 2020.2.4, Kotlin plugin 1.4.20.

💪🏽 1

tjohnn

11/27/2020, 8:07 AM

Hey guys, any advice on mocking in commonTest? I tried mockk without success

Vinod Rai

11/28/2020, 6:30 AM

Hey, Can anyone please guide or provide any link here to generate a native Universal framework with minimum size? I am generating a Universal framework and it's working perfectly but it's increasing IPA size drastically. Here is my build.gradle.kts file.

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import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinNativeTarget

plugins {
    kotlin("multiplatform")
    kotlin("plugin.serialization")
    id("com.squareup.sqldelight")
}

kotlin {
    val iosX64 = iosX64("ios")
    val iosArm64 = iosArm64("iosArm64")
    val iosArm32 = iosArm32("iosArm32")
    val frameworkName = "EmtCore"
    configure(listOf(iosX64, iosArm64, iosArm32)) {
        binaries.framework {
            baseName = frameworkName
        }
    }
    sqldelight {
        database("EmtCoreDatabase") {
            packageName = "com.emt_core.db"
        }
    }
    jvm("android")

    sourceSets["commonMain"].dependencies {
        implementation("org.jetbrains.kotlin:kotlin-stdlib-common")
        implementation("io.ktor:ktor-client-core:1.4.1")
        implementation("io.ktor:ktor-client-json:1.4.1")
        implementation("com.russhwolf:multiplatform-settings-no-arg:0.6.1")
        implementation("io.ktor:ktor-client-serialization:1.4.1")
        implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9-native-mt-2")
        implementation("org.jetbrains.kotlinx:kotlinx-serialization-core:1.0.0-rc")
        implementation("com.soywiz.korlibs.klock:klock:1.12.0")
        implementation("io.ktor:ktor-client-logging:1.4.1")
        implementation("com.squareup.sqldelight:runtime:1.4.3")
    }

    sourceSets["androidMain"].dependencies {
        implementation("org.jetbrains.kotlin:kotlin-stdlib")
        implementation("io.ktor:ktor-client-android:1.4.1")
        //implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.9")
        implementation("org.jetbrains.kotlinx:kotlinx-serialization-core:1.0.0-rc")
        implementation("io.ktor:ktor-client-okhttp:1.4.1")
        api("io.ktor:ktor-client-logging-jvm:1.4.1")
        implementation("io.ktor:ktor-client-json-jvm:1.4.1")
        implementation("io.ktor:ktor-client-serialization-jvm:1.4.1")
        implementation("com.squareup.okhttp3:logging-interceptor:4.4.1")
        implementation("com.squareup.sqldelight:android-driver:1.4.3")

    }

    sourceSets["iosMain"].dependencies {
        implementation("io.ktor:ktor-client-ios:1.4.1")
        //implementation ("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
        implementation("org.jetbrains.kotlinx:kotlinx-serialization-core:1.0.0-rc")
        implementation("io.ktor:ktor-client-json-native:1.3.2")
        api("io.ktor:ktor-client-logging-native:1.3.2")
        implementation("io.ktor:ktor-client-serialization-iosx64:1.4.1")
        //implementation("io.ktor:ktor-client-serialization-iosarm64:1.4.0")
        implementation("com.squareup.sqldelight:native-driver:1.4.3")
    }

    sourceSets["iosArm64Main"].dependencies {
        implementation("io.ktor:ktor-client-ios:1.4.1")
        //implementation ("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
        implementation("org.jetbrains.kotlinx:kotlinx-serialization-core:1.0.0-rc")
        implementation("io.ktor:ktor-client-json-native:1.3.2")
        api("io.ktor:ktor-client-logging-native:1.3.2")
        implementation("io.ktor:ktor-client-serialization-iosarm64:1.4.1")
        //implementation("io.ktor:ktor-client-serialization-iosarm64:1.4.0")
        implementation("com.squareup.sqldelight:native-driver:1.4.3")
    }

    sourceSets["iosArm32Main"].dependencies {
        implementation("io.ktor:ktor-client-ios:1.4.1")
        //implementation ("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.3.9")
        implementation("org.jetbrains.kotlinx:kotlinx-serialization-core:1.0.0-rc")
        implementation("io.ktor:ktor-client-json-native:1.3.2")
        api("io.ktor:ktor-client-logging-native:1.3.2")
        implementation("io.ktor:ktor-client-serialization-iosarm32:1.4.1")
        //implementation("io.ktor:ktor-client-serialization-iosarm64:1.4.0")
        implementation("com.squareup.sqldelight:native-driver:1.4.3")
    }

    val debugFatFramework by tasks.creating(org.jetbrains.kotlin.gradle.tasks.FatFrameworkTask::class) {
        baseName = frameworkName
        from(
           iosArm32.binaries.getFramework("debug"),
            iosArm64.binaries.getFramework("debug"),
            iosX64.binaries.getFramework("debug")
        )
        destinationDir = buildDir.resolve("fat-framework/debug")
        group = "Universal framework"
        description = "Builds a debug universal (fat) framework"
    }

    val releaseFatFramework by tasks.creating(org.jetbrains.kotlin.gradle.tasks.FatFrameworkTask::class) {
        baseName = frameworkName
        from(
            iosArm32.binaries.getFramework("release"),
            iosArm64.binaries.getFramework("release")
        )
        destinationDir = buildDir.resolve("fat-framework/release")
        group = "Universal framework"
        description = "Builds a release universal (fat) framework"
    }

    val zipDebugFatFramework by tasks.creating(Zip::class) {
        dependsOn(debugFatFramework)
        from(debugFatFramework)
       // from("LICENSE.md")
    }

    val zipReleaseFatFramework by tasks.creating(Zip::class) {
        dependsOn(releaseFatFramework)
        from(releaseFatFramework)
        //from("LICENSE.md")
    }
}

Elyes Ben Salah

11/28/2020, 12:15 PM

Hey guys , I just started exploring KMM and I’m new with Kotlin also , and I would like to know if I can work with a Java Library in the common project ( we have our SDK in JAVA) or better to re-write it in Kotlin

Azur Haljeta

11/28/2020, 1:47 PM

The

frameworkName

specified in

cocoapods{}

is ignored when building the

.podspec

file via

./gradlew podspec

. It uses the name of the gradle project, which is also the default value. Any ideas?

andylamax

11/28/2020, 6:59 PM

Hello all, can I setup a Multiplatform lib with a jvm target where,

jvmMain

contains kotlin code, while

jvmTest

contains kotlin and java code? andy gradle sample?

outadoc

11/28/2020, 9:05 PM

Hey all, I’m trying to get a small multiplatform project going, and I’m seeing some weird errors in the IDE. The project builds fine, but both IntelliJ 2020.2.4 and Android Studio 4.1.1 show errors every time I import something from a multiplatform library. There are two multiplatform libs,

lib-kemu

, and

lib-chip8

(which depends on

lib-kemu

locally). Then two multiplatform modules,

app-chip8-desktop

(Kotlin/JVM) and

app-chip8-browser

(Kotlin/JS) which depend on

lib-chip8

. There’s a chance that I’m doing something wrong, but if that’s the case I cannot figure out what. And it’s getting really hard to progress with every line being errored out. 😞 The code is here: https://github.com/outadoc/kemu-chip8

Kuba Petržílka

11/28/2020, 9:37 PM

Hi. I have a multiplatform Spring JVM/React Browser JS project whre I use some kind of RestClient which is my custom coroutine-based wrapper over Spring's HttpTemplate in the JVM part and wrapper over window.fetch in the JS part. I was considering to replace the SpringTemplate with the new Java 11 HttpClient and create some common expected interface for it and extract it to a separate lightweight but multiplatform-enabled RestClient library. But maybe there is already something like that around I just cannot find it. Do you know?

Jide

11/29/2020, 10:00 AM

Hi. I keep getting this error whenever I try adding a pod dependency to my project. Can anyone help? Note: I have cocoapods and cocoapods-generate installed

Cicero

11/30/2020, 1:50 PM

A library right I was wondering about this. In the past when my project was going to happen in React Native I wrote a node library for connectivity and models Is it similar to a node library? Could I also export my network from common as a library? Also brings me to another question, would I to be able to work in my common without having all this android stuff around? I would like to, for example, run my common independently.

nrobi

11/30/2020, 1:58 PM

[KMM] Those who are sharing ViewModels and using SwiftUI on iOS, how do you approach disposing background jobs? I’m exposing a

dispose()

and calling it from my

ObservableObject

’s

deinit

method (which represents my view’s state and essentially wraps my ViewModel while publishing the state to the view). Any thoughts if there is a better way?

➕ 1

Javier

11/30/2020, 3:07 PM

I have a jvm module which is implementing a kotlin multiplatform module that only have jvmMain target. The build is working perfectly and all tests pass. But if I go to some file inside the jvm module, I see that all referecences from jvm multiplatform module are unresolved, anyone know why this is happening?

Philip Dukhov

12/01/2020, 1:06 AM

Does anyone use cocoapods dependencies generated code in kotlin? It works fine, but even after I finished my module, that had dependencies, and don’t change it anymore, each time I change project gradle file, my module with pod dependencies invalidates cache for

cinterop

tasks and run them, and it takes a lot of time. Any way to really cache them? As I understand those create kotlin headers for the libraries. Obviously I only need those to be run when dependencies or a config related to them changed. But now even when those tasks finished and I run build from

Xcode

it doesn’t use the cache and rebuild it again and again.

Frankablu

12/01/2020, 1:32 AM

How do I remove a target from a multiplatform gradle file? I've commented out all the native lines but I'm getting "Task 'nativeMainBinaries' not found in root project 'GoalTradeOffsMP'."

Animesh Sahu

12/01/2020, 8:10 AM

Something weird is happening with me. The commonMain seems to have "kotlin not configured" error while the other modules have no problems for it... Any idea?

aleksey.tomin

12/01/2020, 8:16 AM

Can I perform syntax check mingw code on macOS host? macos/mingw code on linux host? I don’t want to build result - I want only syntax check.

🚫 1

Cicero

12/01/2020, 10:35 AM

Is there a way, besides writing in ios and android, to securely store data in the common without external libraries? A friend of mine said something about storing in secrets but when googling it I didn’t found anything

Daniele B

12/01/2020, 2:48 PM

Sharing a slide I am preparing for my next talk, putting KMP and JetpackCompose and SwiftUI on a timeline

💡 1

👍 3

Tristan Blakers

12/01/2020, 11:35 PM

does anyone know of a multiplatform URL representation, with basic parsing capability? Ktor has one, but it's too heavy to drag into the browser for just one class...

solidogen

12/01/2020, 11:37 PM

JVM backend module sees common classes only inside androidMain - like commonMain and jvmMain do not exist. JS app and Android app modules work fine with commonMain code. Any idea what could go wrong? Android Studio tells me to add dependency on common.commonMain, but of course it doesn't work

Jeff Tycz

12/02/2020, 12:18 AM

I have a KMP library that uses Ktor, 99.9% of the code is in the common package and the only thing in the android and ios is to set the ktor engine. I am not sure about how to provide the necessary dependencies to be used for my library to be used in ios and android. do I have to build a gradle dependency for ios and android just to get the ktor engine and then the common dependency with all the code?

Paul Woitaschek

12/02/2020, 8:16 AM

We are having issues with type inference. I just added the watchos targets as well as the io targets and created a common source set for them (with the hierachical structure enabled). Now the code accessing NSDateComponents does no longer compile. https://developer.apple.com/documentation/foundation/nsdatecomponents/1411355-hour The issue is that

NSDateComponents().hour

is a

Long

in the iosX64Main source set and a

Int

in the

watchOsArm64Main

source set. Is there any way around that?

João Rodrigues

12/02/2020, 1:25 PM

Hey everyone 👋 I've been experimenting with kotlin multiplatform, and following the hands on has been really helpful. However, I think that the hands on is a bit out of date, the code examples don't always match the automatically generated code by the android studio's KMM wizard. I'd really like to follow an updated version of this!