I want to define a Gradle Plugin inside my `build-...

# gradle

[kotlinforandroid]

I want to define a Gradle Plugin inside my build-logic that applies the Jetbrains Compose libraries. But trying it this way results in an error. There is no KotlinMultiplatformExtension#compose property available.

class KmpComposePlugin : Plugin<Project> {
    override fun apply(target: Project) {
        with(target) {
            with(pluginManager) {
                apply("kmp")
                apply("org.jetbrains.compose")
            }

            val extension = extensions.getByType<KotlinMultiplatformExtension>()
            with(extension) {
                jvm()

                sourceSets.commonMain.dependencies {
                    implementation([e-mail])
                }
            }
        }
    }
}

[Chrimaeon]

you need to configure the extenstion. at this point in time where you are trying to access it, its not “applied”.

import org.gradle.kotlin.dsl.configure

extensions.configure<KotlinMultiplatformExtension>{}

[Chrimaeon]

also, please don’t crosspost without reference. the answers might be useful for others.

[kotlinforandroid]

> you need to configure the extenstion. at this point in time where you are trying to access it, its not “applied”.
I changed the code to this but it still doesn't detect it. Is that what you meant by configuring? The compose property is still not accessible within my custom plugin.

extensions.configure<KotlinMultiplatformExtension> {
   jvm()

   sourceSets.commonMain.dependencies {
     implementation(compose.runtime)
   }
}

[hfhbd]

Are you sure the kmp plugin exists?

[Chrimaeon]

You
apply(“kmp”)
That’s not the kotlin Multiplattform plug-in 🤔

[hfhbd]

And if you use precompiled script plugins you can easily write your convention plugins like regular gradle build kts files using the generated extension accessors.

[Vaibhav Jaiswal]

You can access the dependencies from here

val composeDeps = extensions.getByType<ComposeExtension>().dependencies

And then you can apply it like

implementation(composeDeps.runtime)

[kotlinforandroid]

Thank you! That solved it. I didn't notice it was part of the ComposeExtension.
For people stumbling across this: kmp is the ID of my custom plugin above.

[Bekzod]

hmm, it did not recognized in my case. Should I add specific dependency to be able to import it inside build-logic/convention plugin gradle.kts.
here current state of the gradle.
plugins *{*
``kotlin-dsl``
}

_group_ = "uz.uzkassa.buildlogic"

_java_ *{*
_sourceCompatibility_ = JavaVersion._VERSION_1_8_
targetCompatibility = JavaVersion._VERSION_1_8_
}

_dependencies_ *{*
_compileOnly_(_libs_._android_._gradlePlugin_)
_compileOnly_(_libs_._kotlin_._gradlePlugin_)
}

_gradlePlugin_ *{*
plugins *{*

register("androidApplicationCompose")*{*
_id_ = "horeca.compose"
_implementationClass_ = "ComposeMultiplatformConventionPlugin"
}

register("androidApplication")*{*
_id_ = "horeca.feature"
_implementationClass_ = "FeatureMultiplatformConventionPlugin"
}

register("androidLibrary") *{*
_id_ = "horeca.android.library"
_implementationClass_ = "TEST_AndroidLibraryConventionPlugin"
}
}
}

[kotlinforandroid]

This is how my custom plugin registers the compose dependencies

val compose = extensions.getByType<ComposeExtension>().dependencies
            extensions.configure<KotlinMultiplatformExtension> {
                jvm()

                sourceSets.commonMain.dependencies {
                    implementation(compose.material3)
                    implementation(compose.materialIconsExtended)
                    implementation(compose.runtime)
                    implementation(compose.ui)
                }
            }

[Vaibhav Jaiswal]

@Bekzod you need to add this as a compileOnly dependency

compose-gradlePlugin = { module = "org.jetbrains.compose:org.jetbrains.compose.gradle.plugin", version.ref = "compose" }

[Bekzod]

@Vaibhav Jaiswal I added it here: build-logic->convention->build.gradle.kts plugins{alias(_libs_._plugins_._jetbrainsCompose)_}
but it throw exception by asking other compose related configuration. I'm new to KMM, so struggling to set up.

[Vaibhav Jaiswal]

@Bekzod Not in plugins
but in the dependencies block as compileOnly(libs.plugins.jetbrainsCompose