How to access Kotlin DSL extensions from non-build-gradle file?

Question

There are few Kotlin Extensions that come along with org.gradle.kotlin.dsl like android or publishing etc. Say, for publishing, the extension is defined as below

fun org.gradle.api.Project.`publishing`(configure: org.gradle.api.publish.PublishingExtension.() -> Unit): Unit =
    (this as org.gradle.api.plugins.ExtensionAware).extensions.configure("publishing", configure)

That means within mybuild.gradle.kts I can call

publishing {
    // blablabla
}

In my case, I have a separate file that handles publishing defined as random.gradle.kts and is located at totally random directory.

Here, I want to access this publishing extension but not able to do it.

Any suggestions are welcomed.

To give another example android is also not accessible. In my build.gradle.kts I can access android but in my random.gradle.kts I am not able to do it.

android extension is defined as below

val org.gradle.api.Project.`android`: com.android.build.gradle.LibraryExtension get() =
    (this as org.gradle.api.plugins.ExtensionAware).extensions.getByName("android") as com.android.build.gradle.LibraryExtension

In fact, LibraryExtension is also not accessible.

So, how to pass or import those extensions to my random.gradle.kts?

Answer 1

    //build.gradle.kts tested with gradle 6.7
    
    subprojects {
      afterEvaluate {
        (extensions.findByType(com.android.build.gradle.LibraryExtension::class)
          ?: extensions.findByType(com.android.build.gradle.AppExtension::class))?.apply {
    
          println("Found android subproject $name")
          lintOptions.isAbortOnError = false
          compileSdkVersion(30)
          
          if (this is com.android.build.gradle.AppExtension) 
            println("$name is an application")
          
          if (this is com.android.build.gradle.LibraryExtension) {
    
            val publishing =
              extensions.findByType(PublishingExtension::class.java) ?: return@afterEvaluate
    
            val sourcesJar by tasks.registering(Jar::class) {
              archiveClassifier.set("sources")
              from(sourceSets.getByName("main").java.srcDirs)
            }
    
            afterEvaluate {
              publishing.apply {
                val projectName = name
                publications {
                  val release by registering(MavenPublication::class) {
                    components.forEach {
                      println("Publication component: ${it.name}")
                    }
                    from(components["release"])
                    artifact(sourcesJar.get())
                    artifactId = projectName
                    groupId = ProjectVersions.GROUP_ID
                    version = ProjectVersions.VERSION_NAME
                  }
                }
              }
            }
          }
        }
      }
    }