kotlinlang #multiplatform

Hi, I was wondering if anyone had to work with kotlin multiplatform and j2objc in one project. The current shared code stack of our projects is mainly j2objc, but we would like to move it slowly towards kmp. Is there a way to have both cores communicate with each other (or at least communicating one-way)?

Nikita Khlebushkin

02/26/2020, 6:09 PM

I'm running an iOS project with KMP dependency with cocoapods plugin. I ran

podspec

, then specified

pod 'my-pod', :path => '../my-pod'

in project's Podfile and ran

pod install

. I can import classes in Xcode and autocomplete works just fine, but when I try to build it, I get

Undefined symbols for architecture x86_64:
  "_OBJC_CLASS_$_AnalyticsInitParameters", referenced from:
      objc-class-ref in ContentView.o
  "_OBJC_CLASS_$_AnalyticsAnalytics", referenced from:
      objc-class-ref in ContentView.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

What am I doing wrong? Did I skip anything?

Nikita Khlebushkin

02/26/2020, 10:41 PM

Yet another question about cocoapods + KMP: how do I build fat framework (more than one target, eg. iosX64 and iosArm64) using cocoapods?

darkmoon_uk

02/27/2020, 8:58 AM

Just gave an 1h 20m presentation to our head office advocating a K/MP strategy for the future of our product... 🤞fingers crossed!

🙌 3

🤞 4

ritesh

02/27/2020, 9:57 AM

Hey folks 👋 Wondering if

reified inlined function

is not yet supported in KMP for iOS? Basically I have wrapped

Json.nonstrict.parseList

in a different function which looks like

inline fun <reified T : Any> listParser(): List<T> { ... }

. It’s crashing on iOS saying

Uncaught Kotlin exception: kotlin.IllegalStateException: unsupported call of reified inlined function

though it’s working fine on Android. Just wanted to check if it’s not supported or am I doing something wrong 😅

dambakk

02/27/2020, 10:06 AM

This might be a very basic question, and I know there is an

expect/actual

answer to this question, but I cant seem to figure it out. We are using

Klock

to handle dates in our mpp project. How can we expose this type as a

NSDate

for the ios platform?

🇳🇴 2

Jeff

02/27/2020, 12:07 PM

Hello. I have this actual implementation in js and iOS but runBlocking is unresolved. It is only resolved in JVM. Whats the matter?

import kotlinx.coroutines.runBlocking

internal actual fun <T> runTest(block: suspend () -> T): T {
    return runBlocking { block() }
}

Tim Hauptmann

02/27/2020, 12:20 PM

Hey, I use Sqldelight on iOS and want to put my database file into a specific folder:

NativeSqliteDriver(MyDatabase.Schema, "file:///private/var/mobile/Containers/Shared/AppGroup/.../test.db")

But this is forbidden by:

private fun checkFilename(name: String) {
  if (name.contains("/")) {
    throw IllegalArgumentException(
      "File $name contains a path separator"
    )
  }
}

Someone knows the proper way to setup this?

CLOVIS

02/27/2020, 3:07 PM

Is there a good quality guide on how to actually setup unit testing in Kotlin/JS for a multiplatform library? I've been following SO answers & stuff but the best I could find is 2 years old and very imprecise.

Jeff

02/27/2020, 4:51 PM

I am doing a multiplatform library that supports android. Is the JVM target enough in build.gradle or should I add an Android target?

CLOVIS

02/27/2020, 5:42 PM

Hi! I have a problem with the Multiplatform JS setup (with the Gradle plugin). When running:

./gradlew jsTest

I get:

> Task :kotlinNpmInstall FAILED
error package.json: Name contains illegal characters

I tracked it down to this GitHub issue: https://github.com/yarnpkg/yarn/issues/1120 which says it's a problem of whitespace character in the project name. I do have whitespace in the name of my project, since that's allowed with Gradle—but apparently it's not with Yarn. Is there a way to tell the Multiplatform plugin to escape the whitespace with something else (for example underscores) automatically? I found the generated

package.json

build/js/package.json

and the name of the project does contain spaces there as well.

👍 1

Joan Colmenero

02/27/2020, 7:55 PM

Hello guys, I'm playing with Kotlin MP and on my iosMain using Android Studio I'm not able to import libraries like the Log from Swift any idea?

Sebastien Leclerc Lavallee

02/28/2020, 5:21 AM

Hi! I added RxCommon to my multiplatform setup, I want to create an observer inside my swift code to be able to be notified when changes. The class

Observer

is defined inside RxCommon which is linked in the

sourceCommon

source set. If I try to instanciate an Observer, XCode doesn’t find this class. How is it possible to access classes inside external libraries from the Swift code? I can do this inside one of my Android app’s Activity. Thanks!

Nikita Khlebushkin

02/28/2020, 12:01 PM

Hello! I have this error after compiling KMP library with cocoapods

There is a library attached to the project that was compiled with an older Kotlin/Native compiler and can't be read in IDE:
			"analytics-cinterop-Analytics.klib" at $project/analytics/build/classes/kotlin/iosX64/main/analytics-cinterop-Analytics.klib
			Please edit Gradle buildfile(s) to use Kotlin Gradle plugin version 1.3.61. Then rebuild the project and re-import it in IDE.

The only place that I apply multiplatform plugin has

kotlin("multiplatform") version "1.3.61"

How can I fix it?

Orhan Tozan

02/28/2020, 1:59 PM

Hi guys, I already have several modules that have no reference to android/ios. So really pure Kotlin modules, business logic etc. The idea is the following three following repo's: • core • android implementations • ios implementations So I don't want to use the expect, actual mechanism, but just the interface/implementation mechanism. How do I set something like this up?

Sylvain Patenaude

02/28/2020, 3:07 PM

Can I use @Throws in multi-platform (common) code? EDIT: My code is 99% common (with the 1% being some platform-specific tweaks ). But I would still need to add @Throws annotations to several methods so that the iOS consumers of my iOS-generated library can try/catch these methods. Any idea how I could achieve this?

Sebastien Leclerc Lavallee

02/28/2020, 4:53 PM

Hey guys! I did setup exporting dependencies to be able to use a library inside my Swift code. It seems to have worked partially. I’m exporting RXCommon and when inside the Swift code, I see only interfaces and some abstract classes but most of the interesting classes aren’t available. Does that ring a bell to someone? Thanks!

Orhan Tozan

02/29/2020, 12:06 AM

I'm getting the following error for in a common mpp module of mine:

Cannot access built-in declaration 'kotlin.Nothing'. Ensure that you have a dependency on the Kotlin standard library

Orhan Tozan

02/29/2020, 12:13 AM

I invalidated cache and restarted it, why woould this error occur?

nrobi

03/02/2020, 6:40 AM

Does K/N generate `_Nullable`/`_NonNull` annotations for the compiled obj-c code too? If not, why?

Dariusz Rusin

03/02/2020, 7:00 AM

After updating to Android Studio 3.6.1 when I'm running tests they failed when trying find multiplatform classes:

java.lang.NoClassDefFoundError

Orhan Tozan

03/02/2020, 4:48 PM

What needs to be put in the

jvmMain

sourceset for kotlin coroutines? Couldn't find anything at the README of the coroutines repo. Also, is there a reason why this doesn't come out-of-the-box? E.g. when I declare that I want to use kotlin coroutines in the project, it could automatically import the specific platform dependencies itself.

Mike

03/02/2020, 5:54 PM

Hi, I'm hitting extremely long compile times in a kotlin native mpp project during the compileKotlinJvm task. It takes around 10 minutes to build every time I modify something (I am using a very fast machine). I tried running a profiled build and think incremental build is broken for some reason. Has anyone hit similar issues? https://github.com/JetBrains/kotlin-native/issues/3933

Justin Shapiro

03/02/2020, 7:24 PM

Hi, I’m writing a library targeting android and js. I’ve got the aar. Are there examples of running a bundler on the js output?

👀 1

Eben Du Toit

03/03/2020, 8:18 AM

Hi, I wanted to find out if any of you guys know what the status is of #grpc for kotlin multiplatform?

🙄 1

➕ 1

👀 1

Arthur Brum

03/03/2020, 1:45 PM

Hi, Im getting some problems with kotlin coroutines.. I'm trying to use runBlocking in my common code. And since I don't have a JS target (which is the only target that do not accept runBlocking), it should be possible, right? is there a workaround not being through expect/actual implementations?

🇳🇴 1

Nikita Khlebushkin

03/03/2020, 2:00 PM

Hello, is it possible to build for armv7? I'm running it from Xcode and it totally doesn't recognise my cocoapods KMP framework, although it bulds fine for arm64

Andreas Jost

03/03/2020, 2:08 PM

Hi, is there a way to express hierarchy with expect/actual in Multiplatform? Let's say you have an expected class

ViewContainer

, which is a typealias for

View

on Android-side and

UIView

on iOS-side. And an extension function

ViewContainer.setVisibility(isVisible: Boolean)

. And you also have a second expected class

TextField

, which is a typealias for Android

EditText

/ iOS

UITextField

EditText

is a subclass of

TextView

, which is a subclass of

View

UITextField

is a subclass of

UIControl

, which is a subclass of

UIView

. So both are related to `View`/`UIView` (

ViewContainer

). It would be nice to tell that the compiler, so that you can invoke the function

setVisibility()

not only on

ViewContainer

, but also on

TextField

or other related classes. Obviously

expect class TextField : ViewContainer

won't work, because it isn't a direct child class. So one way is not having a hierarchy and copy/paste the same extension function with the same implementation to

TextField

and every View type. But shouldn't there be any better solution?

Title

Andreas Jost

03/03/2020, 2:08 PM

Hi, is there a way to express hierarchy with expect/actual in Multiplatform? Let's say you have an expected class

ViewContainer

, which is a typealias for

View

on Android-side and

UIView

on iOS-side. And an extension function

ViewContainer.setVisibility(isVisible: Boolean)

. And you also have a second expected class

TextField

, which is a typealias for Android

EditText

/ iOS

UITextField

EditText

is a subclass of

TextView

, which is a subclass of

View

UITextField

is a subclass of

UIControl

, which is a subclass of

UIView

. So both are related to `View`/`UIView` (

ViewContainer

). It would be nice to tell that the compiler, so that you can invoke the function

setVisibility()

not only on

ViewContainer

, but also on

TextField

or other related classes. Obviously

expect class TextField : ViewContainer

won't work, because it isn't a direct child class. So one way is not having a hierarchy and copy/paste the same extension function with the same implementation to

TextField

and every View type. But shouldn't there be any better solution?

alex009

03/03/2020, 3:13 PM

https://github.com/mirego/trikot.metaviews may help

also if you want create screens and navigation from common code - you can check https://github.com/icerockdev/moko-widgets/

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