SharedPreferencesMultiplatform is a Kotlin Multiplatform library that provides shared preference functionality across Android and iOS platforms. This library allows you to manage key-value storage in a platform-agnostic way, while using a dependency injection framework like Koin.

• Kotlin Multiplatform support: Use the same code for shared preferences across Android and iOS.
• Simple DI Integration: Easily inject the shared preference instance using Koin or any other DI framework.

Add the library to your commonMain dependencies in your build.gradle.kts file:

kotlin {
    sourceSets {
        commonMain.dependencies {
            implementation("io.github.firelord:sharedpreference-multiplatform:1.0.1")
        }
    }
}

To use SharedPreferencesMultiplatform, you'll need to set up dependency injection (DI). In this example, we'll use Koin as the DI framework.

In your commonMain source set, declare the expected shared preference module:

// commonMain/kotlin/com/firelord/samplecmp/util/SharedPreferenceModule.kt

import org.koin.core.module.Module

expect val sharedPreference: Module

In the iosMain source set, define the actual implementation. You don't need to pass any context on iOS:

// iosMain/kotlin/com/firelord/samplecmp/util/SharedPreferenceModule.kt

import org.koin.dsl.module
import io.github.firelord.sharedpreference.SharedPreference

actual val sharedPreference = module {
    single { SharedPreference("") } // No context required for iOS
}

In the androidMain source set, pass the Android application context to the shared preference instance:

// androidMain/kotlin/com/firelord/samplecmp/util/SharedPreferenceModule.kt

import org.koin.dsl.module
import io.github.firelord.sharedpreference.SharedPreference
import org.koin.android.ext.koin.androidApplication

actual val sharedPreference = module {
    single {
        val context = androidApplication().applicationContext
        SharedPreference(context)
    }
}

In your ViewModel or any other class where you want to use shared preferences, you can inject the instance using Koin.

Example in commonMain:

class MyViewModel(
    private val sharedPreference: SharedPreference
): ScreenModel {
    fun saveData(key: String, value: String) {
        sharedPreference.putString(key, value)
    }

    fun getData(key: String): String? {
        return sharedPreference.getString(key)
    }
}

For a fully working setup, you can refer to the SampleCMP repository, where Koin is used to manage dependencies and Voyager is used for navigation.

The sample includes:

• Koin setup: Integrating SharedPreferencesMultiplatform with Koin for DI.
• Voyager navigation: Using the library within a multiplatform navigation setup.
• Platform-specific code: How to handle shared preferences on both Android and iOS platforms.

This project is licensed under the MIT License. See the LICENSE file for details.