HomePage.kt

data class HomePage(
        val locationInfo: LocationInfo? = null,
        val travelInfo: TravelInfo? = null,
        val weddingLocation: WeddingLocation? = null,
        val weddingInfo: WeddingInfo? = null,
        val weddingDate: WeddingDate? = null,
        val welcome: WelcomeItem? = null
)

HomeRepo.kt

class HomeRepo(userRepo: UserRepo, private val firebaseInstance: DatabaseReference) {

    private val emptyLiveData: LiveData<Resource<HomePage>> by lazy {
        MutableLiveData<Resource<HomePage>>().apply {
            value = Resource.loading()
        }
    }
    
    private var internalLiveData: LiveData<Resource<HomePage>>? = null

    private lateinit var currentLanguage: String

    private val homeLiveData: LiveData<Resource<HomePage>> = Transformations.switchMap(userRepo.getUser()) {
        val language = it.data?.language.orEmpty()
        when {
            language.isBlank() -> emptyLiveData
            internalLiveData == null || language != currentLanguage -> {
                currentLanguage = language
                FirebaseLiveData(
                        reference = firebaseInstance.child(PATH_HOME).child(currentLanguage),
                        resourceType = HomePage::class.java
                ).apply {
                    internalLiveData = this
                }
            }
            else -> internalLiveData
        }
    }

    fun getHomePage(): LiveData<Resource<HomePage>> {
        return homeLiveData
    }
}