Another question in our project we want to have multiple KMM

Question

Another question in our project we want to have multiple KMM Gradle modules which then get bundled by one root Gradle project which will build the JAR Swift Package So far this is what I try to use ```kotlin jvm ios sourceSets commonMain dependencies api project ModuleOne api project ModuleTwo ``` But the generated lib only has 261 bytes it only contains the `META INF MANIFEST MF` and that s it No classes compiled What should I be doing instead

Marc Reichelt · Answer

Interestingly this is documented on <https kotlinlang org docs multiplatform mobile add dependencies html dependency on another multiplatform project> but it doesn t seem to work on my machine

ephemient · Answer

what makes you think this will bundle the projects

ephemient · Answer

in any case the usual advice is to publish everything

Marc Reichelt · Answer

because that s the same way how we can add projects to other projects in a jvm world

ephemient · Answer

in the JVM world it works the same way

Marc Reichelt · Answer

so how do you split code across several modules then

ephemient · Answer

publishing a project with `dependencies api project Module ` does not bundle it it sets up the artifact s metadata to include the dependency by name+version

ephemient · Answer

publish the module and the modules it depends on

Marc Reichelt · Answer

Ah I see So what I would need to do is generate a fat jar which bundles all the referenced jars

Marc Reichelt · Answer

We currently have two Git repos Android iOS with the new multiplatform git repo seperately That Git repo currently is a single Gradle project building a JAR Swift package that can be included in the app projects Now we want to split up that multiplatform project into multiple feature projects to make it easier for multiple teams to work on them Does anyone try something similar and has a good reference for that

ephemient · Answer

publishing a fat jar is already problematic in pure JVM it s even worse with KMP as it relies on Gradle metadata I would advise you to publish normally

Marc Reichelt · Answer

What does publish normally mean to you

Marc Reichelt · Answer

Thank you for helping by the way

Marc Reichelt · Answer

I hope this can be solved in a good way because otherwise we ll be having a hard time using KMM in our project

ephemient · Answer

publishing to a maven repository using Gradle s built in mechanisms which will align all the artifacts and their metadata

ephemient · Answer

e g <https kotlinlang org docs multiplatform publish lib html>

ade · Answer

Are you looking for something like this <https medium com vmware end user computing adding multiple kotlin multiplatform dependencies to an ios app a520fd1dbfc7>

ephemient · Answer

I don t think they are since they re talking about the JAR which is not the same as bundling the native dependencies

ade · Answer

For JARs I would also recommend publishing normally separately For the swift package something like the above is required

Marc Reichelt · Answer

Hmm that would actually be the best world publishing all JARs as single JARs and combining them altogether as a single XCFramework for iOS

Marc Reichelt · Answer

I just wanted to publish a fat JAR as an intermediate step on our way to publish every single JAR artifact but if it s actually easier to publish every single jar I think we should do that thumbsup

Marc Reichelt · Answer

< ade> < ephemient> do you have a good guide how to include all those JARs in the app project later on

ephemient · Answer

just add the repository to `repositories ` and include it like any other binary dependency

Marc Reichelt · Answer

Hmm I ll try to get that working now Let s see where that takes me

ade · Answer

I think it depends if you want to just use it in the KMM module code or actually publish all classes to iOS aswell so that they are available

ephemient · Answer

you can use `mavenLocal ` for local testing

ade · Answer

or rather in my experience you cant link a pure kotlin module into a kmm module so the dependenices must be kmm modules with all the same targets specified

Marc Reichelt · Answer

< ade> I basically want to bundle `FeatureA` `FeatureB` `FeatureC` into a single `Multiplatform xcframework`

Marc Reichelt · Answer

but for the Android world individual `FeatureA jar` and `FeatureB jar` and `FeatureC jar` are actually good thumbsup

ade · Answer

Ok I think you need to create a swift package from a umbrella module that depends on the other KMM modules

ade · Answer

that s how I understand it also based on <https youtrack jetbrains com issue KT 30088>

Marc Reichelt · Answer

Yes that s exactly what I m trying to achieve

ephemient · Answer

thumbsup bundling native dependencies into a single framework makes sense since cocoapods isn t able to follow the GMM KMP metadata itself and it s also a bit similar on the JS Node publishing side where you do need to bundle dependencies that aren t in NPM in order to make them available to library consumers but for JVM it s definitely most natural to just use the existing Maven support

ade · Answer

the kmm submodules can also be published as kmm libraries as long as they are built for each platform of course

Marc Reichelt · Answer

I ll try to do that now and report back slightly smiling face

Marc Reichelt · Answer

So I tried to combine the new `XCFramework` with the blog post you mentioned < ade> but unfortunately it doesn t compile anything for me it doesn t even create a single framework confused

Marc Reichelt · Answer

is there an updated guide for Kotlin 1 6 10 with the `XCFramework` task

ade · Answer

In my project I am using a plugin to create a SPM package <https github com ge org multiplatform swiftpackage>

Marc Reichelt · Answer

yeah we used that plugin before but we stopped using it when we found out that now there is an official `XCFramework` task that creates the framework and we started creating the swift package ourselves because in the end it s just a plain `Package swift` file with the framework zipped together Still using that plugin as well as using `XCFramework` we need to find out how to integrate the different feature modules `FeatureA` `FeatureB` etc