PreferenceDataStore での起動判定

 Androidでの起動判定をDataStoreを使用して実施

忘備録としてプログラムの一部を記載

DataStoreが安定版の1.0.0

// Preferences DataStore
implementation 'androidx.datastore:datastore-preferences:1.0.0'
implementation 'androidx.datastore:datastore-preferences-core:1.0.0'

DataStoreSetting.kt

val Context.dataStore: DataStore<Preferences> by preferencesDataStore(name = "DataStoreSetting")

class DataStoreSetting {
    object PreferenceKey {
        val START_FLAG = booleanPreferencesKey("StartFlag")
    }

    // 起動フラグの取得
    suspend fun getFlag(context: Context): Boolean {

        // DataStoreからフラグを取得
        val flagFlow: Flow<Boolean> = context.dataStore.data
            .catch { exception ->
                if (exception is IOException) {
                    emit(emptyPreferences())
                } else {
                    throw exception
                }
            }.map { preferences ->
                // デフォルト値：false
                preferences[PreferenceKey.START_FLAG] ?: false
            }

        // 起動フラグ取得
        val flag = flagFlow.first()

        return flag
    }

    // 起動フラグの設定
    fun setFlag(context: Context) {
        CoroutineScope(Dispatchers.Main).launch {
            context.dataStore.edit { setting ->
                setting[PreferenceKey.START_FLAG] = true
            }
        }
    }
}

Fragment

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)

    // 非同期処理
    CoroutineScope(Dispatchers.Main).launch {

        val intent: Intent
        // 起動フラグ
        val startFlag = dataStoreSetting.getSetupCompletedFlag(requireContext())

        intent = if (startFlag) {
            Intent(activity, SecondActivity::class.java)
        } else {
            Intent(activity, FirstActivity::class.java)
        }
    }
    dataStoreSetting.setFlag(requireContext())
    startActivity(intent)
}

参考サイト：

https://developer.android.com/topic/libraries/architecture/datastore?hl=ja

https://developer.android.com/codelabs/android-preferences-datastore?hl=ja#0

https://zenn.dev/slowhand/articles/455aa5cd244e90

https://akira-watson.com/android/sharedpreferences.html

https://stackoverflow.com/questions/67265984/is-it-possible-to-read-write-primitive-types-from-datastore-without-flows