LIveData is observed more than twice everytime from acivity and emitting previous data - mvvm

Question

I follow MVVM Login API, with Retrofit ,My problem is livedata is observed more than twice and always emitting previous response when observed from activity, But inside Repository its giving correct response
I tried a lot of solutions from stackoverflow and other websites but still no luck, Tried removing observers also but still getting previous data ,so plz suggest a working solution, I will post my code below,
LoginActivity.kt
private lateinit var loginViewModel: LoginViewModel
loginViewModel = ViewModelProvider(this, ViewModelProvider.NewInstanceFactory()).get(
LoginViewModel::class.java
)
loginViewModel.login(userEmail, pwd)
loginViewModel.getLoginRepository().observe(this, Observer {
val loginResult = it ?: return#Observer
val accessToken = loginResult.user?.jwtToken.toString()
})
val statusMsgObserver = Observer<String> { statusMsg ->
showToast(statusMsg)
})
val errorMsgObserver = Observer<String> { errorMsg ->
// Update the UI
showToast(errorMsg)
})
loginViewModel.getStatusMessage()?.observe(this, statusMsgObserver)
loginViewModel.getErrorStatusMessage()?.observe(this, errorMsgObserver)
LoginViewModel.kt:
class LoginViewModel: ViewModel() {
private var loginRepository: LoginRepository? = null
private var _mutableLiveData = MutableLiveData<LoginAPIResponse?>()
val liveData: LiveData<LoginAPIResponse?> get() = _mutableLiveData
private var responseMsgLiveData:MutableLiveData<String>?= null
private var errorResponseMsgLiveData:MutableLiveData<String>?= null
fun login(username: String, password: String) {
loginRepository = LoginRepository.getInstance()!!
/* Query data from Repository */
//val _mutableLiveData: MutableLiveData<Response<LoginAPIResponse?>?>? = loginRepository?.doLogin(username, password)
_mutableLiveData = loginRepository?.doLogin(username, password)!!
responseMsgLiveData = loginRepository?.respMessage!!
errorResponseMsgLiveData = loginRepository?.loginResponseErrorData!!
}
fun getLoginRepository(): LiveData<LoginAPIResponse?> {
return liveData
}
fun getStatusMessage(): LiveData<String>? {
return responseMsgLiveData
}
fun getErrorStatusMessage(): LiveData<String>? {
return errorResponseMsgLiveData
}
}
LoginRepository.kt:
class LoginRepository {
private val loginApi: ApiEndpoints = RetrofitService.createService(ApiEndpoints::class.java)
val responseData = MutableLiveData<LoginAPIResponse?>()
var respMessage = MutableLiveData<String>()
var loginResponseErrorData = MutableLiveData<String>()
fun doLogin(username: String, password: String)
: MutableLiveData<LoginAPIResponse?> {
respMessage.value = null
loginResponseErrorData.value = null
val params = JsonObject()
params.addProperty("email", username)
params.addProperty("password",password)
val jsonParams = JsonObject()
jsonParams.add("user",params)
loginApi.loginToServer(jsonParams).enqueue(object : Callback<LoginAPIResponse?> {
override fun onResponse( call: Call<LoginAPIResponse?>, response: Response<LoginAPIResponse?> ) {
responseData.value = response.body()
respMessage.value = RetrofitService.handleError(response.code())
val error = response.errorBody()
if (!response.isSuccessful) {
val errorMsg = error?.charStream()?.readText()
println("Error Message: $errorMsg")
loginResponseErrorData.value = errorMsg
} else {
println("API Success -> Login, $username, ${response.body()?.user?.email.toString()}")
}
}
override fun onFailure(call: Call<LoginAPIResponse?>, t: Throwable) {
println("onFailure:(message) "+t.message)
loginResponseErrorData.value = t.message
responseData.value = null
}
})
return responseData
}
companion object {
private var loginRepository: LoginRepository? = null
internal fun getInstance(): LoginRepository? {
if (loginRepository == null) {
loginRepository = LoginRepository()
}
return loginRepository
}
}
}
In onDestroy(),I have removed the observers,
override fun onDestroy() {
super.onDestroy()
loginViewModel.getLoginRepository()?.removeObservers(this)
this.viewModelStore.clear()
}
In LoginActivity, when I observe loginResult it gives previous emitted accessToken first and then again called and giving current accessToken, Similarly observer is called more than twice everytime.
But inside repository,its giving recent data, plz check my code and suggest where I have to correct to get correct recent livedata

Answer 1

Finally i found the solution, In LoginRepository, I declared responseData outside doLogin(), It should be declared inside doLogin()
Since it was outside the method, it always gave previous data first and then current data,
Once I declare inside method problem was solved and now it is working Perfect!!!