Kotlin multi-platform(KMPP) is Kotlin's experimental feature and it provides the ability to share non-UI business logic between different platforms like Android, iOS, Js, Embedded device and many more. This slide covers how to set-up the KMPP project, how does this code sharing works between different platforms and pro-cons of using it.

1. Lunch and Learn
Kotlin Multi-platform
on

2. Topics
• Presentation on Kotlin multi-platform
• Code overview
• Build framework and run a PoC app
• Q&A

3. Vikram Hooda
Mobile application developer

4. Kotlin Multi-platform
• Designed by JetBrains.
• Shares non-ui logic on different platforms and uses
Kotlin language.
• Open source, natively-integrated and optional sharing.
• Code sharing, not cross-platform.
• Current Status: Experimental state

5. Target Platforms
Overview

6. Common
JSJVM Native
Java Android Browser Node
iOS Linux
Window Embedded
.jar .framework.js

7. Configure
KMPP project

8. Create a new Android and iOS project, if you do not
have one.

9. Create a new module(“Shared”) under Android project to
serve common functionality to target platforms.
Shared module

10. Now, create target specific directory under “Shared”
module.
Shared module directory structure

11. Set dependencies and target in Shared module’s
“build.gradle” file.

12. Target configuration
Target configuration

13. Plugin configuration
Plugin configuration

14. Dependencies configuration
Dependencies configuration

15. Shared Logic
Mechanism

16. Common Module
(Shared business logic)
Native Platforms Module
(Android, iOS)
expect actual
“expect/actual” Keywords

17. • “expect” declares in common module.
• expect val plateformName: String //In common code
• “actual” defines in target module.
• actual val plateformName: String = “Android” //In Android code
• actual val plateformName: String = “iOS” //In iOS code
Example of “expect/actual” keyword

18. Pro & Cons

19. Pros
• Code sharing
• Single source of truth for business logic to native platform
• Less refactoring/rewriting efforts
• Time and cost saving

20. Cons
• Lack of libraries support .
• Concurrency complications on iOS.
• Painful debugging and runtime exception tracing on yet
supported on iOS .
• Must to have all targeted platform’s basic knowledge i.e.
Kotlin, Swift, Android and iOS apis.

21. Code
iOS:
https://github.com/vkhooda24/KnowMyCountry-iOS-Multi-platform
Android and Multi-platform:
https://github.com/vkhooda24/KnowMyCountry-Kotlin-Multiplatform

22. Thank you!