hi this is my user repository
class UserRepository(private val appAuth: FirebaseAuth) : SafeAuthRequest(){
suspend fun userLogin(email: String,password: String) : AuthResult{
return authRequest { appAuth.signInWithEmailAndPassword(email,password)}
}
}
this is the SafeAuthRequest class
open class SafeAuthRequest {
suspend fun<T: Any> authRequest(call : suspend () -> Task<T>) : T{
val task = call.invoke()
if(task.isSuccessful){
return task.result!!
}
else{
val error = task.exception?.message
throw AuthExceptions("$error\nInvalid email or password")
}
}
}
calling above things like that
/** Method to perform login operation with custom */
fun onClickCustomLogin(view: View){
authListener?.onStarted()
Coroutines.main {
try {
val authResult = repository.userLogin(email!!,password!!)
authListener?.onSuccess()
}catch (e : AuthExceptions){
authListener?.onFailure(e.message!!)
}
}
}
and my authListener like this
interface AuthListener {
fun onStarted()
fun onSuccess()
fun onFailure(message: String)
}
I am getting an error as the task is not completed
is the correct way to implement the task
I'm using MVVM architectural pattern, so the example I'm going to provide is called from my ViewModel class, that means I have access to viewModelScope. If you want to run a similar code on Activity class, you have to use the Coroutines scope available for your Activity, for example:
val uiScope = CoroutineScope(Dispatchers.Main)
uiScope.launch {...}
Answering your question, what I've done to retrieve login from user repository is this:
//UserRepository.kt
class UserRepository(private val appAuth: FirebaseAuth) {
suspend fun userLogin(email: String, password: String) : LoginResult{
val firebaseUser = appAuth.signInWithEmailAndPassword(email, password).await() // Do not forget .await()
return LoginResult(firebaseUser)
}
}
LoginResult is a wrapper class of firebase auth response.
//ClassViewModel.kt
class LoginFirebaseViewModel(): ViewModel(){
private val _loginResult = MutableLiveData<LoginResult>()
val loginResult: LiveData<LoginResult> = _loginResult
fun login() {
viewModelScope.launch {
try {
repository.userLogin(email!!,password!!).let {
_loginResult.value = it
}
} catch (e: FirebaseAuthException) {
// Do something on firebase exception
}
}
}
}
The code on Activity class would be like this:
// Function inside Activity
fun onClickCustomLogin(view: View){
val uiScope = CoroutineScope(Dispatchers.Main)
uiScope.launch {
try {
repository.userLogin(email!!,password!!).let {
authResult = it
}
}catch (e : FirebaseAuthException){
// Do something on firebase exception
}
}
}
One of the main benefits of using Coroutines is that you convert asynchronous code in sequential one. That means you don't need listeners or callbacks.
I hope this help you
Related
I m relatively new in kotlin flows and I m creating the Login Module using Flows in android. I have been stuck from past few days in flows as I m collecting it in ViewModels but I m facing problem when requesting with wrong Credentials its caching all the state. After entering the right credentials the user navigate to main Activity but the instance of the MainActivity is being created with every emitted State: Example(User Enter 3 wrong Credential and 1 Right Credential: 4 Instance of MainActivity Created). So, Is there any way that I can cancel the previous emit and only show the latest request. I m using the collectLatest as well but its not working too. Below is the code.
LoginActivity
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(mViewBinding.root)
loginListener()
}
override fun onStart() {
super.onStart()
initViews()
handleNetworkChanges()
}
private fun observeLogin() {
lifecycleScope.launchWhenCreated {
mViewModel.loginCredentials.collect { state ->
when(state){
is State.Loading -> {
showLoading()
}
is State.Success -> {
Timber.d("I m in Success" + state.data)
val intent = Intent(this#LoginActivity,MainActivity::class.java)
startActivity(intent)
closeLoading()
finish()
}
is State.Error -> {
val errorResponse = gson.fromJson(state.message,LoginResponse::class.java)
showToast(errorResponse.messages)
closeLoading()
}
}
}
}
}
private fun loginListener() {
mViewBinding.neumorphButtonSignIn.setOnClickListener {
observeLogin()
phoneNumber = mViewBinding.edtPhoneNumber.text.toString()
pin = mViewBinding.oldPIN.text.toString()
if (phoneNumber.isValidPhone()) {
sendLoginCredentials(phoneNumber ,pin)
}
else {
mViewBinding.edtPhoneNumber.snack("Please Enter valid phone number") {
action("ok") {
dismiss()
}
}
}
}
}
private fun sendLoginCredentials(phoneNumber: String , pin: String) = mViewModel.postLoginCredentials("03XXXX" , "1234")
LoginViewModel
#ExperimentalCoroutinesApi
#HiltViewModel
class LoginViewModel #Inject constructor(
private val loginRepository: LoginRepository,
) : ViewModel() {
private val _loginCredentials: MutableStateFlow<State<LoginResponse>> = MutableStateFlow(State.Empty())
val loginCredentials: StateFlow<State<LoginResponse>> get() = _loginCredentials
fun postLoginCredentials(phoneNumber: String, pin: String) {
Timber.d("postLoginCredentials: $phoneNumber + $pin")
_loginCredentials.value = State.loading()
viewModelScope.launch {
loginRepository.login(LoginRequest(phoneNumber,pin))
.map { response -> State.fromResource(response) }
.collect{state -> _loginCredentials.value = state }
}
}
}
LoginRepository
class LoginRepository #Inject constructor(
private val apiInterface: APIInterface
) {
fun login(loginRequest: LoginRequest): Flow<ResponseAPI<LoginResponse>> {
return object : NetworkBoundRepository<LoginRequest, LoginResponse>() {
override suspend fun fetchFromRemote(): Response<LoginResponse> = apiInterface.createLoginRequest(
loginRequest
)
}.asFlow()
}
NetworkBoundRepository
abstract class NetworkBoundRepository<RESULT, REQUEST> {
fun asFlow() = flow<ResponseAPI<REQUEST>> {
val apiResponse = fetchFromRemote()
val remotePosts = apiResponse.body()
if (apiResponse.isSuccessful && remotePosts != null) {
emit(ResponseAPI.Success(remotePosts))
} else {
// Something went wrong! Emit Error state.
emit(ResponseAPI.Failed(apiResponse.errorBody()!!.string()))
}
}.catch { e ->
e.printStackTrace()
emit(ResponseAPI.Failed("Network error! Can't get latest posts."))
}
#MainThread
protected abstract suspend fun fetchFromRemote(): Response<REQUEST>
}
Is there any way that I can create One Instance of MainAcitivity while ignoring the older emitted Responses? Any Operator which can work. Any help in this regard is highly appreciated. Thanks.
Actually, I was calling the observeLogin() from the login click Listener which was creating this mess in my project when I move this to onCreate(). Everything works the way as intended. So, posting this for newbie that won't stuck into this.
here is my code, I am using it for logging in user with google,
This is my viewModel code
fun signInWithGoogle(account: GoogleSignInAccount): LiveData<Resource<Any>> {
val credential = GoogleAuthProvider.getCredential(account.idToken, null)
return liveData (IO){
authRepo.firebaseSignInWithGoogle(credential, object : FetchUser {
override suspend fun onUserDataFetch(user: User) {
this#liveData.emit(Resource.success(user))
}
override suspend fun onError(error: AppError?) {
this#liveData.emit(Resource.error(error, null))
}
})
}
}
This is my code authRepository where i am logging the user in and checking if user already exits in database or not according to that performing the work
suspend fun firebaseSignInWithGoogle(googleAuthCredential: AuthCredential, userCallBack: FetchUser) {
coroutineScope {
firebaseAuth.signInWithCredential(googleAuthCredential).await()
createUpdateUser(userCallBack)
}
}
private suspend fun createUpdateUser(userCallBack: FetchUser) {
val firebaseUser = firebaseAuth.currentUser
if (firebaseUser != null) {
userIntegrator.getUserById(firebaseUser.uid, object : OnDataChanged {
override suspend fun onChanged(any: Any?) {
if (any != null && any is User) {
any.isNew = false
userIntegrator.createUpdateUser(any, userCallBack)
} else {
val user = User()
user.id = firebaseUser.uid
user.name = firebaseUser.displayName
user.email = firebaseUser.email
user.isNew = true
userIntegrator.createUpdateUser(
user,
userCallBack
)
}
}
})
}
}
This is my last class where I am updating the user in database
suspend fun createUpdateUser(user: User, userCallBack: FetchUser) {
if (user.id.isNullOrEmpty()) {
userCallBack.onError(AppError(StatusCode.UnSuccess, ""))
return
}
val dp = databaseHelper.dataFirestoreReference?.collection(DatabaseHelper.USERS)?.document()
dp?.apply {
dp.set(user.toMap()).await().apply {
dp.get().await().toObject(User::class.java)?.let {
userCallBack.onUserDataFetch(it)
}?: kotlin.run {
userCallBack.onError(AppError(StatusCode.Exception,"Unable to add user at the moment"))
}
}
}
}
Now here whole thing is that, I am using a FetchUser interface which look like this
interface FetchUser {
suspend fun onUserDataFetch(user: User)
suspend fun onError(error: AppError?)
}
I just want to get rid of it and looking for something else in coroutines.
Also I just wanted to know the best practice here,
What should I do with it.
Also I want to make it unit testable
There are 2 ways, if you want to call and get result directly, you could use suspendCoroutine. Otherway, if you want to get stream of data like, loading, result, error,... you could try callbackFlow
Exp:
suspend fun yourMethod() = suspendCoroutine { cont ->
// do something
cont.resume(result)
}
suspend fun yourMethod() = callbackFlow {
val callbackImpl = object: yourInterace {
// your implementation
fun onSuccess() {
emit(your result)
}
fun onFailed() {
emit(error)
}
}
handleYourcallback(callbackImpl)
}
I use FirebaseAuth for registration new user
class FirebaseAuthenticationServiceImpl(): FirebaseAuthenticationService {
override fun registerWithEmailAndPassword(email: String, password: String): Boolean {
val registration = FirebaseAuth.getInstance().createUserWithEmailAndPassword(email, password)
.addOnSuccessListener {
println(it.additionalUserInfo?.providerId.toString())
}.addOnFailureListener {
println(it.message.toString())
}
return registration.isSuccessful
}
}
I call function above and every time I get false. After some time I get true
coroutineScope {
try {
if (firebaseService.registerWithEmailAndPassword(email, password)) {
openHomeActivity.offer(Unit)
} else {}
} catch (e: Exception) {}
}
How can I wait for uth result (success/failure) and afer that get that value?
Where is FirebaseAuthenticationService from? Do you need it? The official getting started guide just uses Firebase.auth. With this, you can authenticate using the await() suspend function instead of using the callback approach.
// In a coroutine:
val authResult = Firebase.auth.registerWithEmailAndPassword(email, password).await()
val user: FirebaseUser = authResult.user
if (user != null) {
openHomeActivity.offer(Unit)
} else {
// authentication failed
}
If you are using coroutines you can use suspendCoroutine which is perfect bridge between traditional callbacks and coroutines as it gives you access to the Continuation<T> object, example with a convenience extension function for Task<R> objects :
scope.launch {
val registrationResult = suspendCoroutine { cont -> cont.suspendTask(FirebaseAuth.getInstance().createUserWithEmailAndPassword(email, password) }
}
private fun <R> Continuation<R>.suspendTask(task: Task<R>) {
task.addOnSuccessListener { this.success(it) }
.addOnFailureListener { this.failure(it) }
}
private fun <R> Continuation<R>.success(r : R) = resume(r)
private fun <R> Continuation<R>.failure(t : Exception) = resumeWithException(t)
My problem is, that when I try to get a document out of my database, that this document aka the object is always null. I only have this problem when I use Kotlin Coroutines to get the document out of my database. Using the standard approach with listeners do work.
EmailRepository
interface EmailRepository {
suspend fun getCalibratePrice(): Flow<EmailEntity?>
suspend fun getRepairPrice(): Flow<EmailEntity?>
}
EmailRepository Implementation
class EmailRepositoryImpl #Inject constructor(private val db: FirebaseFirestore) : EmailRepository {
fun hasInternet(): Boolean {
return true
}
// This works! When using flow to write a document, the document is written!
override fun sendEmail(email: Email)= flow {
emit(EmailStatus.loading())
if (hasInternet()) {
db.collection("emails").add(email).await()
emit(EmailStatus.success(Unit))
} else {
emit(EmailStatus.failed<Unit>("No Email connection"))
}
}.catch {
emit(EmailStatus.failed(it.message.toString()))
}.flowOn(Dispatchers.Main)
// This does not work! "EmailEntity" is always null. I checked the document path!
override suspend fun getCalibratePrice(): Flow<EmailEntity?> = flow {
val result = db.collection("emailprice").document("Kalibrieren").get().await()
emit(result.toObject<EmailEntity>())
}.catch {
}.flowOn(Dispatchers.Main)
// This does not work! "EmailEntity" is always null. I checked the document path!
override suspend fun getRepairPrice(): Flow<EmailEntity?> = flow {
val result = db.collection("emailprice").document("Reparieren").get().await()
emit(result.toObject<EmailEntity>())
}.catch {
}.flowOn(Dispatchers.Main)
}
Viewmodel where I get the data
init {
viewModelScope.launch {
withContext(Dispatchers.IO) {
if (subject.value != null){
when(subject.value) {
"Test" -> {
emailRepository.getCalibratePrice().collect {
emailEntity.value = it
}
}
"Toast" -> {
emailRepository.getRepairPrice().collect {
emailEntity.value = it
}
}
}
}
}
}
}
private val emailEntity = MutableLiveData<EmailEntity?>()
private val _subject = MutableLiveData<String>()
val subject: LiveData<String> get() = _subject
Fragment
#AndroidEntryPoint
class CalibrateRepairMessageFragment() : EmailFragment<FragmentCalibrateRepairMessageBinding>(
R.layout.fragment_calibrate_repair_message,
) {
// Get current toolbar Title and send it to the next fragment.
private val toolbarText: CharSequence by lazy { toolbar_title.text }
override val viewModel: EmailViewModel by navGraphViewModels(R.id.nav_send_email) { defaultViewModelProviderFactory }
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
// Here I set the data from the MutableLiveData "subject". I don't know how to do it better
viewModel.setSubject(toolbarText.toString())
}
}
One would say, that the Firebase rules are the problems here, but that should not be the case here, because the database is open and using the listener approach does work.
I get the subject.value from my CalibrateRepairMessageFragment. When I don't check if(subject.value != null) I get a NullPointerException from my init block.
I will use the emailEntitiy only in my viewModel and not outside it.
I appreciate every help, thank you.
EDIT
This is the new way I get the data. The object is still null! I've also added Timber.d messages in my suspend functions which also never get executed therefore flow never throws an error.. With this new approach I don't get a NullPointerException anymore
private val emailEntity = liveData {
when(subject.value) {
"Test" -> emailRepository.getCalibratePrice().collect {
emit(it)
}
"Toast" -> emailRepository.getRepairPrice().collect {
emit(it)
}
// Else block is never executed, therefore "subject.value" is either Test or toast and the logic works. Still error when using flow!
else -> EmailEntity("ERROR", 0F)
}
}
I check if the emailEntity is null or not with Timber.d("EmailEntity is ${emailEntity.value}") in one of my functions.
I then set the price with val price = MutableLiveData(emailEntity.value?.basePrice ?: 1000F) but because emailentity is null the price is always 1000
EDIT 2
I have now further researched the problem and made a big step forward. When observing the emailEntity from a fragment like CalibrateRepairMessageFragment the value is no longer null.
Furthermore, when observing emailEntity the value is also not null in viewModel, but only when it is observed in one fragment! So how can I observe emailEntity from my viewModel or get the value from my repository and use it in my viewmodel?
Okay, I have solved my problem, this is the final solution:
Status class
sealed class Status<out T> {
data class Success<out T>(val data: T) : Status<T>()
class Loading<T> : Status<T>()
data class Failure<out T>(val message: String?) : Status<T>()
companion object {
fun <T> success(data: T) = Success<T>(data)
fun <T> loading() = Loading<T>()
fun <T> failed(message: String?) = Failure<T>(message)
}
}
EmailRepository
interface EmailRepository {
fun sendEmail(email: Email): Flow<Status<Unit>>
suspend fun getCalibratePrice(): Flow<Status<CalibrateRepairPricing?>>
suspend fun getRepairPrice(): Flow<Status<CalibrateRepairPricing?>>
}
EmailRepositoryImpl
class EmailRepositoryImpl (private val db: FirebaseFirestore) : EmailRepository {
fun hasInternet(): Boolean {
return true
}
override fun sendEmail(email: Email)= flow {
Timber.d("Executed Send Email Repository")
emit(Status.loading())
if (hasInternet()) {
db.collection("emails").add(email).await()
emit(Status.success(Unit))
} else {
emit(Status.failed<Unit>("No Internet connection"))
}
}.catch {
emit(Status.failed(it.message.toString()))
}.flowOn(Dispatchers.Main)
// Sends status and object to viewModel
override suspend fun getCalibratePrice(): Flow<Status<CalibrateRepairPricing?>> = flow {
emit(Status.loading())
val entity = db.collection("emailprice").document("Kalibrieren").get().await().toObject<CalibrateRepairPricing>()
emit(Status.success(entity))
}.catch {
Timber.d("Error on getCalibrate Price")
emit(Status.failed(it.message.toString()))
}
// Sends status and object to viewModel
override suspend fun getRepairPrice(): Flow<Status<CalibrateRepairPricing?>> = flow {
emit(Status.loading())
val entity = db.collection("emailprice").document("Kalibrieren").get().await().toObject<CalibrateRepairPricing>()
emit(Status.success(entity))
}.catch {
Timber.d("Error on getRepairPrice")
emit(Status.failed(it.message.toString()))
}
}
ViewModel
private lateinit var calibrateRepairPrice: CalibrateRepairPricing
private val _calirateRepairPriceErrorState = MutableLiveData<Status<Unit>>()
val calibrateRepairPriceErrorState: LiveData<Status<Unit>> get() = _calirateRepairPriceErrorState
init {
viewModelScope.launch {
when(_subject.value.toString()) {
"Toast" -> emailRepository.getCalibratePrice().collect {
when(it) {
is Status.Success -> {
calibrateRepairPrice = it.data!!
_calirateRepairPriceErrorState.postValue(Status.success(Unit))
}
is Status.Loading -> _calirateRepairPriceErrorState.postValue(Status.loading())
is Status.Failure -> _calirateRepairPriceErrorState.postValue(Status.failed(it.message))
}
}
else -> emailRepository.getRepairPrice().collect {
when(it) {
is Status.Success -> {
calibrateRepairPrice = it.data!!
_calirateRepairPriceErrorState.postValue(Status.success(Unit))
}
is Status.Loading -> _calirateRepairPriceErrorState.postValue(Status.loading())
is Status.Failure -> _calirateRepairPriceErrorState.postValue(Status.failed(it.message))
}
}
}
price.postValue(calibrateRepairPrice.head!!.basePrice)
}
}
You can now observe the status in one of your fragments (but you dont need to!)
Fragment
viewModel.calibrateRepairPriceErrorState.observe(viewLifecycleOwner) { status ->
when(status) {
is Status.Success -> requireContext().toast("Price successfully loaded")
is Status.Loading -> requireContext().toast("Price is loading")
is Status.Failure -> requireContext().toast("Error, Price could not be loaded")
}
}
This is my toast extensions function:
fun Context.toast(text: String, duration: Int = Toast.LENGTH_SHORT) {
Toast.makeText(this, text, duration).show()
}
I Am using MVVM architecture to simple project. Then i stack in this case, when i have to return value from Model DataSource (Lambda function) to Repository then ViewModel will observe this repository. Please correct me if this not ideally and give me some advise for the true MVVM in android. i want to use LiveData only instead of RxJava in this case, because many sample in Github using RxJava.
In my Model i have class UserDaoImpl, code snippet like below
class UserDaoImpl : UserDao {
private val resultCreateUser = MutableLiveData<AppResponse>()
private val mAuth : FirebaseAuth by lazy {
FirebaseAuth.getInstance()
}
override fun createUser(user: User) {
mAuth.createUserWithEmailAndPassword(user.email, user.password)
.addOnCompleteListener {
//I DID NOT REACH THIS LINE
println("hasilnya ${it.isSuccessful} ")
if(it.isSuccessful){
val appResponse = AppResponse(true, "oke")
resultCreateUser.postValue(appResponse)
}else{
val appResponse = AppResponse(false, "not oke -> ${it.result.toString()}")
resultCreateUser.postValue(appResponse)
}
}
.addOnFailureListener {
println("hasilnya ${it.message}")
val appResponse = AppResponse(false, "not oke -> ${it.message}")
resultCreateUser.postValue(appResponse)
}
}
override fun getResultCreateUser() = resultCreateUser
}
And this is my Repository snippet code
class RegisterRepositoryImpl private constructor(private val userDao: UserDao) : RegisterRepository{
companion object{
#Volatile private var instance : RegisterRepositoryImpl? = null
fun getInstance(userDao: UserDao) = instance ?: synchronized(this){
instance ?: RegisterRepositoryImpl(userDao).also {
instance = it
}
}
}
override fun registerUser(user: User) : LiveData<AppResponse> {
userDao.createUser(user)
return userDao.getResultCreateUser() as LiveData<AppResponse>
}
}
Then this is my ViewModel
class RegisterViewModel (private val registerRepository: RegisterRepository) : ViewModel() {
val signUpResult = MutableLiveData<AppResponse>()
fun registerUser(user: User){
println(user.toString())
val response = registerRepository.registerUser(user)
signUpResult.value = response.value
}
}
If i execute the snippet code above, the result always nullpointer in signUpResult
This is my Activity
lateinit var viewModel: RegisterViewModel
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_register)
initializeUI()
}
private fun initializeUI() {
val factory = InjectorUtils.provideRegisterViewModelFactory()
viewModel = ViewModelProviders.of(this, factory).get(RegisterViewModel::class.java)
viewModel.signUpResult.observe(this, Observer {
//IT always null
if(it.success){
// to HomeActivity
Toast.makeText(this, "Success! ${it.msg}", Toast.LENGTH_SHORT).show()
}else{
Toast.makeText(this, "FALSE! ${it.msg}", Toast.LENGTH_SHORT).show()
}
})
register_btn.setOnClickListener {
val username = name.text.toString()
val email = email.text.toString()
val password = password.text.toString()
val phone = number.text.toString()
val user = User(0, username,"disana", email, password, "disana")
viewModel.registerUser(user)
}
}
Crash occured when i press register button
I'm not 100% sure, but I think the problem is in your ViewModel, where you are trying to pass by reference MutableLiveData. Your Activity is observing signUpResult MutableLiveData, but you are never posting new value, you are trying to change reference of that LiveData to one in Repository.
val signUpResult = MutableLiveData<AppResponse>()
fun registerUser(user: User){
println(user.toString())
val response = registerRepository.registerUser(user)
signUpResult.value = response.value
}
I think that the solution here is to let your ViewModel return LiveData, which is returned from Repository.
fun registerUser(user: User): MutableLiveData<AppResponse> {
println(user.toString())
return registerRepository.registerUser(user)
}
And you need to observe function registerUser(user) in your Activity.
viewModel.registerUser(user).observe(this, Observer {
But now you encountered another problem. By this example you will trigger observe method every time your button is clicked. So you need to split in repository your function, you need to make one only for returning userDao.getResultCreateUser() as LiveData<AppResponse>, and the other to trigger userDao.create(user) .
So you can make two functions in your repository
override fun observeRegistrationResponse() : LiveData<AppResponse> {
return userDao.getResultCreateUser() as LiveData<AppResponse>
}
override fun registerUser(user: User) {
userDao.createUser(user)
}
Now also in ViewModel you need to make separate function for observing result and for sending request for registration.
fun observeRegistrationResponse(): LiveData<AppResponse> {
return registerRepository.observeRegistrationResponse()
}
fun registerUser(user: User){
println(user.toString())
registerRepository.registerUser(user)
}
And finally you can observe in your function initializeUI
viewModel.observeRegistrationResponse().observe(this, Observer {
And send registration request on button click
viewModel.registerUser(user)
Sorry for long response, but I tried to explain why you need to change your approach. I hope I helped you a bit to understand how LiveData works.