Use plugin function in extension -> project.provider

Help/Discuss
1

A similar question has already been posted in june 2020 without a solution.

In my buildSrc/src/main/kotlin/version-convention.gradle.kts convention plugin I have the following function:

fun prefixFrom(name: String): String =
    name.replace("_", "-") // simplified

I would like to use this function a few lines later:

open class GitVersionExtension @Inject constructor(
    project: Project
) {
    val prefix: Property<String> = project.objects.property(String::class.java)
        .convention(project.provider {
            prefixFrom(project.name)
        })
}

This fails with a java.lang.ArrayIndexOutOfBoundsException.

1 Like
2

Because the function is called in the project context I have to pass it using the extra functionality:

fun prefixFrom(name: String): String =
    name.replace("_", "-")

// Put the function into the extra variables:
val gitVersionPrefixFrom by extra<(String) -> String>(::prefixFrom)

open class GitVersionExtension @Inject constructor(
    project: Project
) {
    val prefix: Property<String> = project.objects.property(String::class.java)
        .convention(project.provider {
            // retrieve the function from the extra variables:
            val gitVersionPrefixFrom: (String) -> String by project.extra
            gitVersionPrefixFrom(project.name)
        })
}

I don’t think that it is possible to hide the function from users of the plugin.