Sample FeedRepository using NetworkBoundResouce class

FeedRepository.kt

class FeedRepository @Inject constructor(
        private val feedService: FeedService,
        private val feedDao: FeedDao,
        private val appExecutors: AppExecutors = AppExecutors()
) {

    fun getFeeds(): LiveData<Resource<List<Feed>?>> = object : NetworkBoundResource<List<Feed>, List<Feed>>(appExecutors) {
        override fun saveCallResult(item: List<Feed>) {
            feedDao.insertAll(item)
        }

        override fun shouldFetch(data: List<Feed>?): Boolean = data == null || data.isEmpty()

        override fun loadFromDb(): LiveData<List<Feed>> = feedDao.getFeeds()

        override fun createCall(): LiveData<ApiResponse<List<Feed>>> = feedService.getFeeds()
    }.asLiveData()
}