cdmunoz

class CryptocurrenciesViewModelFactory @Inject constructor(
    private val cryptocurrenciesViewModel: CryptocurrenciesViewModel) : ViewModelProvider.Factory {

  override fun <T : ViewModel> create(modelClass: Class<T>): T {
    if (modelClass.isAssignableFrom(CryptocurrenciesViewModel::class.java!!)) {
      return cryptocurrenciesViewModel as T
    }
    throw IllegalArgumentException("Unknown class name")
  }
}

cdmunoz

class CryptocurrenciesActivity : AppCompatActivity() {

  @Inject
  lateinit var cryptocurrenciesViewModelFactory: CryptocurrenciesViewModelFactory
  lateinit var cryptocurrenciesViewModel: CryptocurrenciesViewModel

  override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(layout.activity_main)
    AndroidInjection.inject(this)

cdmunoz

@Module
class AppModule(val app: Application) {

  companion object {
    val MIGRATION_1_2: Migration = object : Migration(1, 2){
      override fun migrate(database: SupportSQLiteDatabase) {
        // Change the table name to the correct one
        database.execSQL("ALTER TABLE cryptocurrency RENAME TO cryptocurrencies")
      }
    }

cdmunoz

@Entity(
    tableName = "cryptocurrencies"
)
data class Cryptocurrency(

    @Json(name = "id")
    @PrimaryKey
    val id: String,

    @Json(name = "name")

cdmunoz

@Dao
interface CryptocurrenciesDao {

  @Query("SELECT * FROM cryptocurrencies ORDER BY rank limit :limit offset :offset")
  fun queryCryptocurrencies(limit:Int, offset:Int): Single<List<Cryptocurrency>>

  // ... rest of the code
}

cdmunoz

class CryptocurrencyRepository @Inject constructor(val apiInterface: ApiInterface,
    val cryptocurrenciesDao: CryptocurrenciesDao, val utils: Utils) {

  fun getCryptocurrencies(limit: Int, offset: Int): Observable<List<Cryptocurrency>> {
    val hasConnection = utils.isConnectedToInternet()
    var observableFromApi: Observable<List<Cryptocurrency>>? = null
    if (hasConnection){
      observableFromApi = getCryptocurrenciesFromApi()
    }
    val observableFromDb = getCryptocurrenciesFromDb(limit, offset)

cdmunoz

class CryptocurrencyRepository @Inject constructor(val apiInterface: ApiInterface,
    val cryptocurrenciesDao: CryptocurrenciesDao, val utils: Utils) {

  fun getCryptocurrencies(limit: Int, offset: Int): Observable<List<Cryptocurrency>> {
    val hasConnection = utils.isConnectedToInternet()
    var observableFromApi: Observable<List<Cryptocurrency>>? = null
    if (hasConnection){
      observableFromApi = getCryptocurrenciesFromApi()
    }
    val observableFromDb = getCryptocurrenciesFromDb(limit, offset)

cdmunoz

class CryptocurrencyRepository @Inject constructor(val apiInterface: ApiInterface,
    val cryptocurrenciesDao: CryptocurrenciesDao, val utils: Utils) {

  fun getCryptocurrencies(limit: Int, offset: Int): Observable<List<Cryptocurrency>> {
    val hasConnection = utils.isConnectedToInternet()
    var observableFromApi: Observable<List<Cryptocurrency>>? = null
    if (hasConnection){
      observableFromApi = getCryptocurrenciesFromApi()
    }
    val observableFromDb = getCryptocurrenciesFromDb(limit, offset)

cdmunoz

class Utils @Inject constructor(private val context: Context) {

  fun isConnectedToInternet(): Boolean {
    val connectivity = context.getSystemService(
        Context.CONNECTIVITY_SERVICE) as ConnectivityManager
    if (connectivity != null) {
      val info = connectivity.allNetworkInfo
      if (info != null)
        for (i in info.indices)
          if (info[i].state == NetworkInfo.State.CONNECTED) {

cdmunoz

class Utils @Inject constructor(private val context: Context) {

  fun isConnectedToInternet(): Boolean {
    val connectivity = context.getSystemService(
        Context.CONNECTIVITY_SERVICE) as ConnectivityManager
    if (connectivity != null) {
      val info = connectivity.allNetworkInfo
      if (info != null)
        for (i in info.indices)
          if (info[i].state == NetworkInfo.State.CONNECTED) {