Swift Klib Gradle Plugin

This gradle plugin provides easy way to include your Swift source files in your Kotlin Multiplatform Mobile shared module and access them in Kotlin via cinterop for iOS targets. It is useful for:

Accessing Swift-only libraries (e.g. CryptoKit)
Creating a Kotlin-Friendly Swift API
Learning how Swift <-> Kotlin interoperability works

Note: Plugin has been tested on Gradle 7.5+, Xcode 13+

Installation

Using the plugins DSL:

plugins {
    id("io.github.ttypic.swiftklib") version "0.3.0"
}

Using legacy plugin application:

buildscript {
  repositories {
    maven {
      url = uri("https://plugins.gradle.org/m2/")
    }
  }
  dependencies {
    classpath("io.github.ttypic:plugin:0.3.0")
  }
}

apply(plugin = "io.github.ttypic.swiftklib")

Usage

Plugin works together with Kotlin Multiplatform plugin.

Prepare Swift code

Place your Swift files inside your project in separate folder (e.g. native/HelloSwift).

Make sure that Swift API you want to expose to Kotlin is compatible with Objective-C.

@objc public class HelloWorld : NSObject {
    @objc public class func helloWorld() -> String {
        return "HeLLo WorLd!"
    }
}

Setup swiftklib extension

Then you need to add cinterop for target platforms in your Kotlin Multiplatform Plugin. There is no need to configure it or add .def file, all configuration will be done automatically by Swift Klib.

kotlin {
    listOf(
        iosX64(),
        iosArm64(),
        iosSimulatorArm64(),
    ).forEach {
        it.compilations {
            val main by getting {
                cinterops {
                    create("HelloSwift")
                }
            }
        }
    }

    //...
}

And finally provide settings for it in swiftklib extension. You need to specify path and packageName parameters.

swiftklib {
    create("HelloSwift") {
        path = file("native/HelloSwift")
        packageName("com.ttypic.objclibs.greeting")
    }
}

Examples

More samples can be found in the examples/ folder.

License

This package is licensed under MIT license.