problem solved related to count down timer of resend otp with viewmodel architect

app/src/main/java/com/woka/onboard/fragments/GetCodeFragment.kt

@@ -49,8 +49,6 @@ class GetCodeFragment : Fragment() {
     private lateinit var viewModel: OnboardViewModel
     private lateinit var progressView: ProgressView
 
-    private lateinit var countDownTimer: CountDownTimer
-
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         arguments?.let {
@@ -81,21 +79,22 @@ class GetCodeFragment : Fragment() {
     override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
         super.onViewCreated(view, savedInstanceState)
 
-        // count down timer
-        startCountDown()
-
         // observing live data
         viewModel.sendOTPLiveData.observe(viewLifecycleOwner){
             when(it){
                 is ApiResult.Error -> {
                     progressView.hide()
                     Toast.makeText(activity, "${it.errorMessage}", Toast.LENGTH_SHORT).show()
+
+                    // stating null status for otp sent live data so that when user goes back to the otp screen
+                    // they do not encounter a success status again
+                    viewModel.clearSendOTPData()
                 }
                 is ApiResult.Loading -> {
                     progressView.show("Sending OTP...")
                 }
                 is ApiResult.Success -> {
-                    startCountDown()
+                    viewModel.startOTPTimeCountDown()
                     Toast.makeText(activity, "OTP sent successfully", Toast.LENGTH_SHORT).show()
                     progressView.hide()
                     uniqueString = it.data?.unique_string?:""
@@ -130,14 +129,30 @@ class GetCodeFragment : Fragment() {
                 null -> {}
             }
         }
+
+        viewModel.otpResendTimeLiveData.observe(viewLifecycleOwner){
+            if (it == 0L){
+                // no time is ticking
+                binding.countdown.visibility = GONE
+                binding.resend.visibility = VISIBLE
+            }else{
+                // time is ticking
+                binding.countdown.visibility = VISIBLE
+                binding.resend.visibility = GONE
+
+                val rms = (it)/1000 // remaining time in second
+                val time = "%02d:%02d".format(rms/60, rms%60)
+                val text = "OTP is valid for $time Min"
+                Log.d("aditya_testing", "onTick: $it")
+                binding.countdown.text = text
+            }
+        }
     }
 
     override fun onDestroyView() {
         super.onDestroyView()
         viewModel.clearValidateOTP()
         viewModel.clearSendOTPData()
-
-        countDownTimer.cancel()
     }
 
     private fun initViews() {
@@ -205,25 +220,6 @@ class GetCodeFragment : Fragment() {
         }
     }
 
-    private fun startCountDown(){
-        binding.countdown.visibility = VISIBLE
-        binding.resend.visibility = GONE
-
-        countDownTimer = object :CountDownTimer(OTP_RESEND_COUNT_DOWN_TIME, 1000){
-            override fun onTick(millisUntilFinished: Long) {
-                val rms = (millisUntilFinished)/1000 // remaining time in second
-                val time = "%02d:%02d".format(rms/60, rms%60)
-                val text = "OTP is valid for $time Min"
-                binding.countdown.text = text
-            }
-
-            override fun onFinish() {
-                binding.countdown.visibility = GONE
-                binding.resend.visibility = VISIBLE
-            }
-        }.start()
-    }
-
     private fun getOTP(): String {
         binding.apply {
             return "${et1.text}${et2.text}${et3.text}${et4.text}"

app/src/main/java/com/woka/onboard/fragments/GetEmailFragment.kt

@@ -90,50 +90,12 @@ class GetEmailFragment : Fragment() {
                 null -> {}
             }
         }
-
-        viewModel.sendOTPLiveData.observe(viewLifecycleOwner) {
-            when (it) {
-                is ApiResult.Error -> {
-                    progressView.hide()
-                    Toast.makeText(activity, "${it.errorMessage}", Toast.LENGTH_SHORT).show()
-                }
-
-                is ApiResult.Loading -> {
-                    progressView.show(title = "Sending OTP")
-                }
-
-                is ApiResult.Success -> {
-                    viewModel.clearSendOTPData()
-                    progressView.hide()
-
-                    val args = if (isResetPasswordIntent) {
-                        Bundle().apply {
-                            putBoolean(IS_RESET_PASSWORD_INTENT, isResetPasswordIntent)
-                        }
-                    } else {
-                        Bundle().apply {
-                            putBoolean(IS_UNDER_16, isUnder16)
-                            putString(UNIQUE_STRING_ARG, it.data?.unique_string)
-                            putString(EMAIL_ARG, binding.email.text.toString())
-                        }
-                    }
-
-                    findNavController().navigate(
-                        R.id.action_getEmailFragment_to_getCodeFragment,
-                        args
-                    )
-                }
-
-                null -> {}
-            }
-        }
     }
 
     override fun onDestroyView() {
         super.onDestroyView()
         // removing values from live data for a fresh data when new instance is created
         viewModel.clearCheckEmailExist()
-        viewModel.clearSendOTPData()
     }
 
     private fun initViews() {
@@ -167,6 +129,43 @@ class GetEmailFragment : Fragment() {
                 return@setOnClickListener
             }
 
+            // listening to otp live data
+            viewModel.sendOTPLiveData.observe(viewLifecycleOwner) {
+                when (it) {
+                    is ApiResult.Error -> {
+                        progressView.hide()
+                        Toast.makeText(activity, "${it.errorMessage}", Toast.LENGTH_SHORT).show()
+                    }
+
+                    is ApiResult.Loading -> {
+                        progressView.show(title = "Sending OTP")
+                    }
+
+                    is ApiResult.Success -> {
+                        progressView.hide()
+
+                        val args = if (isResetPasswordIntent) {
+                            Bundle().apply {
+                                putBoolean(IS_RESET_PASSWORD_INTENT, isResetPasswordIntent)
+                            }
+                        } else {
+                            Bundle().apply {
+                                putBoolean(IS_UNDER_16, isUnder16)
+                                putString(UNIQUE_STRING_ARG, it.data?.unique_string)
+                                putString(EMAIL_ARG, binding.email.text.toString())
+                            }
+                        }
+
+                        findNavController().navigate(
+                            R.id.action_getEmailFragment_to_getCodeFragment,
+                            args
+                        )
+                    }
+
+                    null -> {}
+                }
+            }
+
             if (!isUnder16) {
                 // parent
                 viewModel.checkEmailExist(binding.email.text.toString(), PARENT_TYPE)

app/src/main/java/com/woka/onboard/mvvm/OnboardViewModel.kt

@@ -1,5 +1,6 @@
 package com.woka.onboard.mvvm
 
+import android.os.CountDownTimer
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
@@ -106,4 +107,29 @@ class OnboardViewModel: ViewModel(){
             _checkUserNameExistLiveData.postValue(response)
         }
     }
+
+    // otp count down timer
+    private val OTP_RESEND_COUNT_DOWN_TIME = 10 * 60 * 1000L // 10 min
+
+    private var countDownTimer: CountDownTimer? = null
+    private var _otpResendTimeLiveData = MutableLiveData<Long>()
+    val otpResendTimeLiveData: LiveData<Long>
+        get() = _otpResendTimeLiveData
+
+    fun startOTPTimeCountDown(){
+        countDownTimer?.cancel()
+        countDownTimer = object : CountDownTimer(OTP_RESEND_COUNT_DOWN_TIME, 1000){
+            override fun onTick(millisUntilFinished: Long) {
+                _otpResendTimeLiveData.postValue(millisUntilFinished)
+            }
+            override fun onFinish() {
+                _otpResendTimeLiveData.postValue(0)
+            }
+        }.start()
+    }
+
+    override fun onCleared() {
+        super.onCleared()
+        countDownTimer?.cancel()
+    }
 }

app/src/main/res/layout/fragment_get_code.xml

@@ -216,7 +216,7 @@
         android:id="@+id/countdown"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
-        android:visibility="visible"
+        android:visibility="gone"
 
         tools:text="OTP is valid for 10:00 Min"
         android:textColor="@color/color_primary"