Firebase Send Email Link

Auth with Firebase Email Link (detailed manual)

Photo by Solen Feyissa on Unsplash

0️⃣ Set up the project and plug Firebase:

https://firebase.google.com/docs/android/setup

1️⃣ Add Firebase Auth and Firebase Dynamic Link:

Get Started with Firebase Authentication on Android

Receive Firebase Dynamic Links on Android

implementation platform('com.google.firebase:firebase-bom:28.2.0')
implementation 'com.google.firebase:firebase-auth-ktx'
implementation 'com.google.firebase:firebase-dynamic-links-ktx'

2️⃣ ⬇️

Auth:

Dynamic Link:

3️⃣⬇️

4️⃣ Copy: [ your_name_app.firebaseapp.com ]:

5️⃣ Create a constant and paste the copied URL:

companion object {
    const val FIREBASE_DEFAULT_DOMAIN = "https://your_name_app.firebaseapp.com"
}

6️⃣ Create ActionCodeSettings:

Passing State in Email Actions | Firebase

private fun getActionCodeSettings() = actionCodeSettings {
    url = "$FIREBASE_DEFAULT_DOMAIN"
    handleCodeInApp = true
    setIOSBundleId("com.example.ios")
    setAndroidPackageName(BuildConfig.APPLICATION_ID, true, null)
}

7️⃣ Create Layout:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/edit_email"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:hint="Email"
        app:autoSizeTextType="uniform"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHeight_percent=".1"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintWidth_percent=".5" />

    <Button
        android:id="@+id/btn_send"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:maxLines="1"
        android:text="send"
        app:autoSizeTextType="uniform"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintDimensionRatio="1:1"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/edit_email"
        app:layout_constraintWidth_percent=".3" />

</androidx.constraintlayout.widget.ConstraintLayout>

8️⃣ Plug in the viewBinding:

https://developer.android.com/topic/libraries/view-binding

9️⃣ Implement code sending signIn link to email:

package com.example.demofirebasesendemaillink

import android.os.Bundle
import android.util.Log
import android.util.Patterns
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import com.example.demofirebasesendemaillink.databinding.ActivityMainBinding
import com.google.firebase.auth.FirebaseAuth
import com.google.firebase.auth.ktx.actionCodeSettings

class MainActivity : AppCompatActivity() {

    companion object {
        const val FIREBASE_DEFAULT_DOMAIN = "https://demofirebasesendemaillink.firebaseapp.com"
    }

    private lateinit var binding: ActivityMainBinding
    private val auth = FirebaseAuth.getInstance()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.btnSend.setOnClickListener {
            val email = binding.editEmail.text.toString()

            if (Patterns.EMAIL_ADDRESS.matcher(email).matches()) {
                auth.sendSignInLinkToEmail(email, getActionCodeSettings())
                    .addOnSuccessListener {
                        Toast.makeText(this, "Success", Toast.LENGTH_SHORT).show()
                    }
                    .addOnFailureListener {
                        Toast.makeText(this, "Failure: $it", Toast.LENGTH_SHORT).show()
                    }
            } else {
                Toast.makeText(this, "Not Email", Toast.LENGTH_SHORT).show()
            }
        }
    }

    private fun getActionCodeSettings() = actionCodeSettings {
        url = "$FIREBASE_DEFAULT_DOMAIN"
        handleCodeInApp = true
        setIOSBundleId("com.example.ios")
        setAndroidPackageName(BuildConfig.APPLICATION_ID, true, null)
    }

}

Attention: emails may come in SPAM because this example project

BONUS: If you want to transfer useful data:

Add to Firebase in project settings SHA256:

You can get it like this:

Add the data we need:

private fun getActionCodeSettings() = actionCodeSettings {
    url = "$FIREBASE_DEFAULT_DOMAIN" + "/?email=your_email@gmail.com"
    handleCodeInApp = true
    setIOSBundleId("com.example.ios")
    setAndroidPackageName(BuildConfig.APPLICATION_ID, true, null)
}

BONUS: If you want to get data from the link:

var email: String? = null
private fun getData(intent: Intent) {
    FirebaseDynamicLinks.getInstance().getDynamicLink(intent)
        .addOnSuccessListener {
            if (it != null && it.link != null) {
                email = it.link!!.getEmail()
            }
        }
}

private fun Uri.getEmail(): String? {
    return getQueryParameter("continueUrl")
        ?.toUri()
        ?.getQueryParameter("email")
}

GIT: https://github.com/Vladislav-Shesternin/DemoFirebaseSendEmailLink

PS. Vel_daN: Love what You DO 💚.