I’m trying to flesh out some architecture for MVVM, but I’m not entirely sure how to bind viewmodels (VMs) to views. My questions are best asked through an example. So here’s a simple VM:

class MyVM(
    private val vmDidSummonLoadingScreen: () -> Unit,
    private val vmDidDismissLoadingScreen: () -> Unit
)
{
    fun doAFlip() 
    {
        vmDidSummonLoadingScreen()
        startSuperLongAsyncTask {
            vmDidDismissLoadingScreen()
        }
    }
}

Here’s some example UI in Android

class FMMain: Fragment()
{
    val loadingScreenVw: View get() = fm_main_vw_loading_screen	//From XML

    val vm: MyVM by lazy {                                //Problem a1
        MyVM(
            vmDidSummonLoadingScreen = {                  //Problem a0
                loadingScreenVw.visibility = View.VISIBLE
            },
            vmDidDismissLoadingScreen = {                 //Problem a0
                loadingScreenVw.visibility = View.GONE
            }
        )
    }

    override fun onCreate(...)
    {
        super.onCreate(...)
        vm.doAFlip()
    }
}

Problems: a0: The lambdas will leak the instance of FMMain since the lambdas reference a property of FMMain thereby implicitly capturing it. a1: Assuming the lambdas don’t leak, when the device rotates, the UI dies and so does the VM. There is the Android Component Library ViewModel class that solves this, but that can’t be used in the shared module. iOS is excluded because this architecture works pretty well since Swift has [weak self] to prevent strong captures. So my questions are: 1: How does one release lambda captures? 1.1: If not possible, what is the best way to let the UI layer know that an event happened in the VM without using any external libs/dependencies (just idomatic kotlin)? 2: Only in Android, I am considering wrapping my VM with an object that inherits from Android’s Architecture Components’ ViewModel (possibly generic idk if I can do that yet). Is there a better alternative in your opinion? 3. In your opinion, should VMs be injected into Fragments, or should Fragments instantiate and own their own VMs?

Is it possible to generate reference documentation for a MPP library?

When using maven-publish plugin with MPP project, how do i publish transitive dependencies metadata? e.g.: I have module A and core module B that depends on A. I publish both and include module B to some project, but module A is not added as module B dependency to that project

does anyone know of a multiplatform UI abstraction layer? in particular something that allows me to create the same tabs, textfields, dropdowns, etc in html/js and tornadofx ? (and potentially android/iOS later)

What is suggested way of creating singletons that will work on ios/jvm?

man I can't believe I waited this long to switch my MPP build scripts to Kotlin DSL. so much nicer.

Any good multiplatform examples with Kotlin dsl instead of Groovy? I’ve been holding off on the conversion but it’s probably time.

has anyone had issues with this:

apply(plugin = "com.android.library")

in build scripts written in Kotlin DSL?

Is there a blog post or sample app utilizing gradle kotlin DSL to publish KMP library (android and iOS) to bintray?

Also -- just wanted to confirm that

@OptionalExpectation

only works for annotations at the moment, and doesn't automatically create no-op implementations for interfaces, right?

Hey! was wondering how to mock objects in a unit test for IOS since mockk doesn’t support that yet?

Hey guys, I was wondering how I can annotate fun to be static for objective-c, similar like we have @JvmStatic?

I'm experimenting with extracting common logic into a common kotlin module, which I then compile to Javascript and want to consume in a typescript project (as an npm module). The dependency via NPM works, but I am unsure as to where I would put my typescript definition files. Tried putting them in

jsMain/resources

, but those files never show up in the NPM project that's generated by the gradle plugin. Moreover: I am applying the "multiplatform" plugin in a subproject, but the javascript npm projects are still generated in the top level project build folder and there is also an NPM project generated for the top level project (which does not have the multiplatform plugin!). The NPM project that actually contains my js code is put into

build/js/packages/<root project name>-<subproject name>

. How can I disable this? I just want a plain NPM project for the javascript code.

Hello, everyone. I have an unusual question. What is the disadvantages or restrictions of Kotlin Multiplatform. Maybe you planned to use this approach but during implementation faced some troubles or problems? Or maybe you just know other side ( or sides ) of this technology? I am asking because I used it for three projects, but my experience is positive. I want to present this technique in my company and start using it. But I almost sure that question about disadvantages will be asked, I know that they exist, but I am not aware of them.

Does anybody know if there’s a way to config library exports for native with cocoapods? You can config that on frameworks without cocoapods, but not sure with

binaries {
    framework {
        export project(':dependency')
        // Export transitively.
        transitiveExport = true
    }
}

Config block from here: https://kotlinlang.org/docs/reference/building-mpp-with-gradle.html

How to iterate over api dependencies? I want something like: configurations.api.files that will give list of all jars that are api dependency api and jvmApi gives error: "Resolving configuration 'jvmApi' directly is not allowed"

interesting commentary from Roman on multi-threaded coroutines: "To give you some more detail on what's holding us back. kotlinx.coroutines is a multiplatform library. Currently all the "multithreading-capable" data structures are part of JVM compilation only while Native and JS contains simple stubs. In order to support multi-threading on Native we need to share this code between JVM and Native, while leaving stubs for JS. Unfortunately, our current MPP model in Kotlin (which is still experimental) does not support this. We are working on its next version code-named "Hierarchical MPP" (HMPP) which enable this kind of fine-grained sharing."

Where can I find the documentation for the new Kotlin JS Gradle Plugin? And can I use this in MPP?

how to add new source directory to

commonMain

sourceSet in multiplatform gradle project?

should compilation of a

jvm

target trigger the compilation of the

commonMain

?

I read that the Multiplatform Plugin is supposed to compile only the targets requested of it, but Gradle is consistently building the (irrelevant) iOS Framework target, while building a depending Android project. 🐢 ⏱️ The Android project itself is not multiplatform - do I need to specify in the project dependency to only build the Android target?

Hello! Fast question. It's possible to use Kotlin reflection in Kotlin Multiplatform? Only from common module, not on iOS or Android. Building at this moment a wrapper over Firebase Firestore and I want to cast a convert a class to a

Map<Field,Value>

for pass it to iOS library.

How do you get a reference to Jars downloded from maven for the JS target in Kotlin DSL? I need to unpack them for the assemble web! If i try to use

configurations["jsApi"].singleFile

it errors with:

Resolving configuration 'jsApi' directly is not allowed

We are using SQLDelight with Coroutines in a Kotlin Multiplatform project. Hope this is the right place to ask. We couldn't really fully grasp the limitations on Kotlin Native. Our iOS team has pending questions regarding performance and whether if we will actually be doing database I/O operation on main thread. Can someone enlighten me and point me to right direction? Thanks.

Differences between a few of these seem... subtle? Nonexistent?

Any way to run all the tests from all the platforms at once? When I try to do an

app -> Run all tests

there are no tests founds. I need to run individually the folders of each platform and on iOS case I need to run the gradle script for it. Any idea about how to unify this?

Hello guys, I am trying to use UnsingedIntegers in my multi-platform project. I use it almost everywhere and I want to pass the compiler flag to avoid using annotations everywhere (https://kotlinlang.org/docs/reference/experimental.html#module-wide-use). I am also using the gradle kotlin-multiplatform and could someone tell me where I can put the compiler flag in the plugin?

How to reference items from “android.app” and “android.util” (like Application or Log) in SharedCode/androidMain?

Now I’m struggling with

NoClassDefFoundError

in jvm module. It doesn’t see the class from shared module 🤔