As with every new technology, I like to briefly browse the documentation or watch some YouTube videos to get a general idea of what it is about. This video from JetBrains was released just a day ago at the time of writing this report, and it was helpful. Then, I followed the "Get Started" page and created a project using the KMP wizard. I encountered some issues while building the project. I also tried creating a project using Android Studio, but that one had a different structure. Allegedly, this should be KMM (Kotlin Multiplatform Mobile), unless I was misled by LLMs. I continued working on the project created through the KMP wizard, and the build problems were resolved by invalidating the caches. I decided to develop an app that saves data into local storage (using SharedPreferences on Android and NSUserDefaults on iOS).
I decided to implement a platform-specific API call with the help of AI. Initially, I worked with Claude. The prompt I used was very basic and not detailed:
I would like to generate access code to a local storage for a write and read operations on Kotlin Multiplatform.
The prompt generated a lot of code, more than I had asked for. It included operations beyond just reading and writing. It also implemented a Factory pattern, which was probably overkill for my use case. I started copying certain parts and pasting the code into my project, and everything began to make perfect sense. The files were nicely split across multiple folders.
composeApp/src/commonMain/kotlin/package/LocalStorage.kt - shared code that based on the platform will resolve to the correct implementation
composeApp/src/iosMain/kotlin/package/LocalStorage.ios.kt - actual implementation for iOS
composeApp/src/androidMain/kotlin/package/LocalStorage.android.kt - actual implementation for Android
After this, I needed to check how to actually use it. I noticed that Android Studio is equipped with the Gemini assistant. I pasted the LocalStorage.kt class into Gemini and asked how to use it. The output was usable.
To use local storage in my App.kt file, where our layout lies, I needed to modify the entry points for each specific platform and pass local storage as an argument. In the case of Android, it is MainActivity.kt, and in iOS, it is MainViewController.kt. After this, essentially, the feature was done.
I think that this feature was basic enough that no special prompts or prompt engineering techniques were required.
The UI of the app was implemented by me. It was pretty straightforward. I leveraged the default UI and just added some text fields, buttons, and polished it a bit. Of course, I had to Google some attributes if I could not figure them out on my own. I chose to build it on my own because I have experience with Flutter, which also has a similar way of building UIs, and I really liked that about Flutter. This approach is much better than the old XML files.
Very basic app. I have not encountered any specific technical problems or challenges, except for the hassles with the project build.
