android-jetpack

How would you write TypeConverter for Map? My approach was to do it by Moshi class Converters() { val moshi = Moshi .Builder() .add(KotlinJsonAdapterFactory()) .build() val mapOfStringsType = Types.newParameterizedType(Map::class.java, String::class.java, String::class.java) val mapOfStringsAdapter = moshi.adapter<Map<String, String>>(mapOfStringsType) @TypeConverter fun stringToMap(data: String): Map<String, String> { return mapOfStringsAdapter.fromJson(data).orEmpty() } @TypeConverter fun mapToString(map: Map<String, String>): String { return mapOfStringsAdapter.toJson(map) } } However, it

How can I easily get the count of the database size so I can then do the appropriate actions based on whether the DB is empty or not? I have an App DB, View Model, Repository, Dao, and all the other pieces, and my objects insert... But I cannot call in onCreate() the size of the list in the DB. When I ever try to get mAppDatabase.vehicleDao().getAll().getValue().size() , or mVehicleViewModel.getAll().getValue().size() , I get null pointer exceptions. However I know my objects are inserting because when I run an observable, I can log their information... but I cannot get the count on the main

Our team are building a project with benefits from Android Jetpack. There are demo code showing the question we are facing. These code can be found at https://github.com/viseator/TestRoomLivedata I create a UserDao : @Dao interface UserDao { @Query("SELECT * FROM user WHERE uid = :uid LIMIT 1") fun findUserById(uid: String?): Single<User> @Query("SELECT * FROM user WHERE state = 1 LIMIT 1") fun findLoginUserWithObserve(): LiveData<User> @Query("SELECT * FROM user WHERE state =1 LIMIT 1") fun findLoginUser(): Single<User> @Update fun update(vararg user: User) } I also created a kotlin object to