Datastore.kt

class DatastoreManager(
    private val context: Context
): DataStorePreferenceAPI {

    companion object{
        fun getInstance(context: Context) = DatastoreManager(context)

        //Create an instance of the datastore
        private val Context.dataStore by preferencesDataStore(
            name = "my_datastore"
        )
    }

    //Return the value stored in the datastore via a Flow (stream of data)
    override suspend fun <T> getPreference(key: Preferences.Key<T>):
            Flow<T?> = context.dataStore.data.catch { exception ->
        if (exception is IOException) {
            emit(emptyPreferences())
        } else {
            throw exception
        }
    }.map { preferences ->
        preferences[key]
    }

    //Write a preference using a key and its value
    override suspend fun <T> putPreference(key: Preferences.Key<T>, value: T) {
        context.dataStore.edit { preferences ->
            preferences[key] = value
        }
    }

    //Delete a specific preference
    override suspend fun <T> removePreference(key: Preferences.Key<T>) {
        context.dataStore.edit {
            it.remove(key)
        }
    }

    //Clearing all preferences
    override suspend fun clearAllPreference() {
        context.dataStore.edit { preferences ->
            preferences.clear()
        }
    }
}

//Generic API to write/read onto the DataStore Preferences easily
interface DataStorePreferenceAPI {

    suspend fun<T> getPreference(key: Preferences.Key<T>): Flow<T?>
    suspend fun<T> putPreference(key: Preferences.Key<T>, value: T)
    suspend fun<T> removePreference(key: Preferences.Key<T>)
    suspend fun clearAllPreference()

}