refactor(email): move Firebase calls to ViewModel

Author: thatfiredev

auth/app/src/main/java/com/google/firebase/quickstart/auth/kotlin/EmailPasswordFragment.kt

@@ -1,31 +1,24 @@
 package com.google.firebase.quickstart.auth.kotlin
 
-import android.content.Intent
 import android.os.Bundle
-import android.text.TextUtils
-import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
-import android.widget.Toast
-import androidx.core.os.bundleOf
-import androidx.navigation.fragment.findNavController
-import com.google.firebase.auth.FirebaseAuth
-import com.google.firebase.auth.FirebaseAuthMultiFactorException
-import com.google.firebase.auth.FirebaseUser
-import com.google.firebase.auth.ktx.auth
-import com.google.firebase.ktx.Firebase
-import com.google.firebase.quickstart.auth.R
+import androidx.core.view.isGone
+import androidx.fragment.app.viewModels
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.lifecycleScope
+import androidx.lifecycle.repeatOnLifecycle
 import com.google.firebase.quickstart.auth.databinding.FragmentEmailpasswordBinding
+import kotlinx.coroutines.launch
 
 class EmailPasswordFragment : BaseFragment() {
-
-    private lateinit var auth: FirebaseAuth
-
     private var _binding: FragmentEmailpasswordBinding? = null
     private val binding: FragmentEmailpasswordBinding
         get() = _binding!!
 
+    private val viewModel by viewModels<EmailPasswordViewModel>()
+
     override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
         _binding = FragmentEmailpasswordBinding.inflate(inflater, container, false)
         return binding.root
@@ -41,200 +34,50 @@ class EmailPasswordFragment : BaseFragment() {
             emailSignInButton.setOnClickListener {
                 val email = binding.fieldEmail.text.toString()
                 val password = binding.fieldPassword.text.toString()
-                signIn(email, password)
+
+                viewModel.signIn(email, password)
             }
             emailCreateAccountButton.setOnClickListener {
                 val email = binding.fieldEmail.text.toString()
                 val password = binding.fieldPassword.text.toString()
-                createAccount(email, password)
-            }
-            signOutButton.setOnClickListener { signOut() }
-            verifyEmailButton.setOnClickListener { sendEmailVerification() }
-            reloadButton.setOnClickListener { reload() }
-        }
 
-        // Initialize Firebase Auth
-        auth = Firebase.auth
-    }
-
-    public override fun onStart() {
-        super.onStart()
-        // Check if user is signed in (non-null) and update UI accordingly.
-        val currentUser = auth.currentUser
-        if(currentUser != null){
-            reload();
-        }
-    }
-
-    private fun createAccount(email: String, password: String) {
-        Log.d(TAG, "createAccount:$email")
-        if (!validateForm()) {
-            return
+                viewModel.createAccount(email, password)
+            }
+            signOutButton.setOnClickListener { viewModel.signOut() }
+            verifyEmailButton.setOnClickListener { viewModel.sendEmailVerification() }
+            reloadButton.setOnClickListener { viewModel.reload() }
         }
 
-        showProgressBar()
-
-        auth.createUserWithEmailAndPassword(email, password)
-                .addOnCompleteListener(requireActivity()) { task ->
-                    if (task.isSuccessful) {
-                        // Sign in success, update UI with the signed-in user's information
-                        Log.d(TAG, "createUserWithEmail:success")
-                        val user = auth.currentUser
-                        updateUI(user)
-                    } else {
-                        // If sign in fails, display a message to the user.
-                        Log.w(TAG, "createUserWithEmail:failure", task.exception)
-                        Toast.makeText(context, "Authentication failed.",
-                                Toast.LENGTH_SHORT).show()
-                        updateUI(null)
-                    }
-
-                    hideProgressBar()
-                }
-    }
-
-    private fun signIn(email: String, password: String) {
-        Log.d(TAG, "signIn:$email")
-        if (!validateForm()) {
-            return
-        }
+        lifecycleScope.launch {
+            viewLifecycleOwner.repeatOnLifecycle(Lifecycle.State.STARTED) {
+                viewModel.uiState.collect { uiState ->
+                    // Handle errors
+                    binding.fieldEmail.error = uiState.emailError
+                    binding.fieldPassword.error = uiState.passwordError
 
-        showProgressBar()
+                    // Display texts
+                    binding.status.text = uiState.userId
+                    binding.detail.text = uiState.userEmail
 
-        auth.signInWithEmailAndPassword(email, password)
-                .addOnCompleteListener(requireActivity()) { task ->
-                    if (task.isSuccessful) {
-                        // Sign in success, update UI with the signed-in user's information
-                        Log.d(TAG, "signInWithEmail:success")
-                        val user = auth.currentUser
-                        updateUI(user)
+                    // Toggle progress bar
+                    if (uiState.isProgressBarVisible) {
+                        showProgressBar()
                     } else {
-                        // If sign in fails, display a message to the user.
-                        Log.w(TAG, "signInWithEmail:failure", task.exception)
-                        Toast.makeText(context, "Authentication failed.",
-                                Toast.LENGTH_SHORT).show()
-                        updateUI(null)
-                        checkForMultiFactorFailure(task.exception!!)
+                        hideProgressBar()
                     }
 
-                    if (!task.isSuccessful) {
-                        binding.status.setText(R.string.auth_failed)
-                    }
-                    hideProgressBar()
+                    // Toggle button visibility
+                    binding.verifyEmailButton.isGone = !uiState.isVerifyEmailVisible
+                    binding.emailPasswordButtons.isGone = !uiState.isSignInEnabled
+                    binding.emailPasswordFields.isGone = !uiState.isSignInEnabled
+                    binding.signedInButtons.isGone = uiState.isSignInEnabled
                 }
-    }
-
-    private fun signOut() {
-        auth.signOut()
-        updateUI(null)
-    }
-
-    private fun sendEmailVerification() {
-        // Disable button
-        binding.verifyEmailButton.isEnabled = false
-
-        // Send verification email
-        val user = auth.currentUser!!
-        user.sendEmailVerification()
-                .addOnCompleteListener(requireActivity()) { task ->
-                    // Re-enable button
-                    binding.verifyEmailButton.isEnabled = true
-
-                    if (task.isSuccessful) {
-                        Toast.makeText(context,
-                                "Verification email sent to ${user.email} ",
-                                Toast.LENGTH_SHORT).show()
-                    } else {
-                        Log.e(TAG, "sendEmailVerification", task.exception)
-                        Toast.makeText(context,
-                                "Failed to send verification email.",
-                                Toast.LENGTH_SHORT).show()
-                    }
-                }
-    }
-
-    private fun reload() {
-        auth.currentUser!!.reload().addOnCompleteListener { task ->
-            if (task.isSuccessful) {
-                updateUI(auth.currentUser)
-                Toast.makeText(context, "Reload successful!", Toast.LENGTH_SHORT).show()
-            } else {
-                Log.e(TAG, "reload", task.exception)
-                Toast.makeText(context, "Failed to reload user.", Toast.LENGTH_SHORT).show()
             }
         }
     }
 
-    private fun validateForm(): Boolean {
-        var valid = true
-
-        val email = binding.fieldEmail.text.toString()
-        if (TextUtils.isEmpty(email)) {
-            binding.fieldEmail.error = "Required."
-            valid = false
-        } else {
-            binding.fieldEmail.error = null
-        }
-
-        val password = binding.fieldPassword.text.toString()
-        if (TextUtils.isEmpty(password)) {
-            binding.fieldPassword.error = "Required."
-            valid = false
-        } else {
-            binding.fieldPassword.error = null
-        }
-
-        return valid
-    }
-
-    private fun updateUI(user: FirebaseUser?) {
-        hideProgressBar()
-        if (user != null) {
-            binding.status.text = getString(R.string.emailpassword_status_fmt,
-                    user.email, user.isEmailVerified)
-            binding.detail.text = getString(R.string.firebase_status_fmt, user.uid)
-
-            binding.emailPasswordButtons.visibility = View.GONE
-            binding.emailPasswordFields.visibility = View.GONE
-            binding.signedInButtons.visibility = View.VISIBLE
-
-            if (user.isEmailVerified) {
-                binding.verifyEmailButton.visibility = View.GONE
-            } else {
-                binding.verifyEmailButton.visibility = View.VISIBLE
-            }
-        } else {
-            binding.status.setText(R.string.signed_out)
-            binding.detail.text = null
-
-            binding.emailPasswordButtons.visibility = View.VISIBLE
-            binding.emailPasswordFields.visibility = View.VISIBLE
-            binding.signedInButtons.visibility = View.GONE
-        }
-    }
-
-    private fun checkForMultiFactorFailure(e: Exception) {
-        // Multi-factor authentication with SMS is currently only available for
-        // Google Cloud Identity Platform projects. For more information:
-        // https://cloud.google.com/identity-platform/docs/android/mfa
-        if (e is FirebaseAuthMultiFactorException) {
-            Log.w(TAG, "multiFactorFailure", e)
-            val resolver = e.resolver
-            val args = bundleOf(
-                    MultiFactorSignInFragment.EXTRA_MFA_RESOLVER to resolver,
-                    MultiFactorFragment.RESULT_NEEDS_MFA_SIGN_IN to true
-            )
-            findNavController().navigate(R.id.action_emailpassword_to_mfa, args)
-        }
-    }
-
     override fun onDestroyView() {
         super.onDestroyView()
         _binding = null
     }
-
-    companion object {
-        private const val TAG = "EmailPassword"
-        private const val RC_MULTI_FACTOR = 9005
-    }
 }