For Kotlin Multimodule Multiplatform projects, how...

# multiplatform

[janvladimirmostert]

For Kotlin Multimodule Multiplatform projects, how does one configure the plugin block?

Currently doing it per sub project

plugins {
	val kotlinVersion = "1.4.10"
	kotlin("multiplatform") version kotlinVersion
	kotlin("plugin.serialization") version kotlinVersion
}

but it no longer compiles complaining that i'm redefining the Kotlin plugin
i guess this now needs to move to the

allprojects {

block in the root build.gradle.kts

i'm trying

allprojects {
  	plugins.apply(kotlin("multiplatform"))
}

but that's not compiling

any ideas?

[mbonnin]

What you can do is define the version in the root project without applyting them:

//root/build.gradle.kts
plugins {
  kotlin("multiplatform").version("1.4.10").apply(false)
}

Then in your individual modules apply them without version:

//root/module/build.gradle.kts
plugins {
  kotlin("multiplatform")
}

[janvladimirmostert]

that's nifty!
i take it i can just apply(true) to have it applied to all submodules as well, all modules are Kotlin

[mbonnin]

plugins {
  kotlin("multiplatform")
}

is the same as

plugins {
  kotlin("multiplatform").apply(true)
}

[janvladimirmostert]

is the plugin definition required in teh submodules if apply(true) is in the root ?

[mbonnin]

You don't want to apply(true) from the root project since there's no kotlin file to compile there

[mbonnin]

What kotlin("multiplatform").version("1.4.10").apply(false) in the root project does is that it adds the Kotlin plugin jar to the buildscript classpath.

[mbonnin]

This ensures that this is made in a single central place

[janvladimirmostert]

this is brilliant, you just saved me from having to redefine versions all over the place, thanks for this!

can the same be done with dependencies ?

[mbonnin]

You can look into java platforms for dependencies

[janvladimirmostert]

i see dependencies block works in allprojects, so i guess the answer is yes

[mbonnin]

Basically you define a "platform" module that centralizes all the different versions and that all your other modules depend on https://docs.gradle.org/current/userguide/java_platform_plugin.html

[janvladimirmostert]

thanks for the help Martin!

[mbonnin]

you can use allprojects {} too

[mbonnin]

Although you're certainly more looking for subprojects {} to exclude the root project (which doesn't contain any kotlin in typical cases)

[janvladimirmostert]

yeah, i've got a build.finished block which loops through all projects and it contains the root project which i currently have to exclude

gradle.buildFinished {

		allprojects.forEach { subproject ->
		val lib = "$buildDir/library/${project.name}-${subproject.name}"

subprojects might be a better solution here too

thanks for the help Martin, this is going to make my KMMMP setup much cleaner 😄