DataStores (Local Storage)¶

The Starter Template provides a unified DataStore setup for local storage in Kotlin Multiplatform projects. You can use it in both Compose and non-Compose code for storing simple preferences like String, Int, Boolean, Long, or Set<String>.

Compose-Friendly Usage¶

Immutable State¶

Use rememberDataStoreValue to read values as immutable state:

Compose Example - Immutable

val themeMode by rememberStringDataStore("theme_mode", "LIGHT")
val isDynamic by rememberBooleanDataStore("dynamic_colors", false)

Other helpers:

val counter by rememberIntDataStore("counter", 0)
val tags by rememberStringSetDataStore("tags", emptySet())

These automatically collect DataStore values as a State<T> that updates on changes.

Mutable State¶

Use rememberMutableDataStoreState to read and write values:

Compose Example - Mutable

var themeMode by rememberMutableStringDataStore("theme_mode", "LIGHT")
var isDynamic by rememberMutableBooleanDataStore("dynamic_colors", false)

// Update value
themeMode = "DARK"
isDynamic = true

// Remove value by setting it to null
themeMode = null

Other helpers:

var counter by rememberMutableIntDataStore("counter", 0)
var lastSync by rememberMutableLongDataStore("lastSync", 0L)

Note: In Compose, setting a mutable DataStore state to null will remove the key from DataStore.

Non-Compose Usage¶

Non-Compose Example

class UserDataStore(appDataStore: AppDataStore) {
    companion object {
        private val ACCESS_TOKEN_KEY = stringPreferencesKey("access_token")
    }

    private val dataStore = appDataStore.dataStore

    val accessTokenFlow = dataStore.data.map { prefs ->
        prefs[ACCESS_TOKEN_KEY]
    }

    suspend fun setAccessToken(token: String?) {
        dataStore.edit { prefs ->
            if (token == null) prefs.remove(ACCESS_TOKEN_KEY)
            else prefs[ACCESS_TOKEN_KEY] = token
        }
    }
}

Note

AppDataStore is a singleton class that is injected into the UserDataStore class automatically.

Support My Project ☕️¶

If you find this project useful, consider supporting it by buying me a coffee. Your support will help me to continue working on this project and add more features.