How to implement Login and signup with Firebase Authentication in android studio.
In this blog, we will be learning how
to login and authenticate in our Android application but
with the help of Firebase.
Following is how the flow of this blog looks like:
· Introduction
to Firebase
· Login
and Authentication in Firebase
· Example - Email login and registration
· Closing notes
Introduction to Firebase
Following are the products of Firebase
that can be used in any applications:
- Cloud Firestore: It is a
NoSQL database that is used to easily store, sync, and query data for
applications.
- ML Kit: It gives
the power of Machine Learning to your applications.
- Authentication: It is
used to authenticate the users of your applications.
- Realtime Database: It is
used to store and retrieve data in realtime.
- Test Labs: It will
test your applications on the devices hosted by Google.
- Crashlytics: It
provides you with the crash reports of your application.
- Performance Monitoring: Monitors the performance of your application at each and every
second.
- In-App Messaging: It helps
you to send in-app messages that helps your users to interact with you.
- Google Analytics: It will
generate a report of your application. For example, a report of users
increased in the last one month or active users, etc.
- Remote Config: It helps
you to change or add some feature in your app even without putting any
update.
Apart from the above-mentioned products
of Firebase, some of the other Firebase products are Cloud
Functions, Hosting, Cloud Storage, App
Distribution, Predictions, A/B Testing, Cloud
Messaging and Dynamic Links.
In this blog, we will learn about the authentication part of the Firebase.
Login and Authentication in Firebase
Firebase authentication is used to authenticate the users of applications in a very easy manner. Not only for the users but for the developers also, it provides a very easy flow for the authentication and login process that is present in almost every application.
Firebase supports authentication using email and password, phone numbers or even you can use facebook, google, twitter, github, etc.
To authenticate your users, all you need to do is get the authentication credentials from the user and then pass this credential to the Firebase Authentication SDK. These credentials can be email-password or mobile number or any token from identity providers like facebook, google, twitter, github, etc. After passing the credentials, Firebase will verify the credentials and in return, you will get a response that tells you if the authentication is successful or not.
Now, let's see how we can use Firebase login
or authentication in our application.
Example - Email login and registration
To use Firebase Authentication in our application,
we need to connect our project i.e. the Android Studio project to Firebase.
Following are the steps that are used to connect an Android project to
Firebase:
Step 2: In Android Studio, login with your email.
You can find the login button at the top right corner of the Android Studio.
(Remember the email id that you have used here)
Step 3: Open the Firebase Website and login into it. (use the
same email id as used in Android Studio for login)
Step 4: After login, click on the "Go
To Console" button that is present of the upper right side of the
website.
Step 5: Click on "Add Project".
Step 6: Enter the required details of the project and click on submit.
Step 8: In this blog, we are interested in the authentication part, so
click on the "Authentication" button and then switch to "Sign-in
method" tab.
Step 9: In our example, we will signin by email. So, click on the edit
button next to the "Email/Password" option and you will see
the below screen.
Step 10: Enable
Email/Password signin and click on "Save". You are done with
the Firebase website part.
Step 11: Come
back to your project in Android Studio and click on Tools > Firebase
> Authentication.
Step 12: We are almost done, now we have to add our project in Android
Studio with the project that we have created in the Firebase. So, click on "Email
and password authentication". Here, we are having two options i.e. "Connect to Firebase" and "Add Firebase Authentication to your
app". Firstly, we have to connect our project to Firebase, so, click
on "Connect to Firebase" button.
Step 13: A
list of projects, associated with your email will be displayed and you have to
select the project that you have created earlier on Firebase and then click on
"Connect to Firebase".
Step 14: Now,
your project on the Android Studio is connected with the one present on the
Firebase. Lastly, we have to add some dependencies to our projects. So, click
on "Add Firebase Authentication to your app". A dialog box
will be opened. Click on "Accept Changes" and it will
automatically add all the dependencies to your project.
Finally, we are done with all the steps that are required
to connect our Android Studio project with Firebase for Authentication. Now,
let's move on to the coding part.
In this example, we will be having four activities:
1) MainActivity:This is the main activity of
the application. The user will be redirected to this activity if the user is
successfully logged in or have created a new account. In the MainActivity, we
are having options for changing password and Logout.
2) LoginAcitivty: This
activity is used to login the user into the application and after successful
login, transfer the user to MainActivity. It contains two EditText for taking
email and password from the user. Two buttons for Login and Signup(signup
button will transfer the user to the SignupActivity) and one TextView that will
transfer the user to the ForgotPasswordActivity.
3) SignupActivity: This activity is used to register the user into the application and after successful registration, transfer the user to the MainActivtiy. It contains two EditText for taking email and password from the user for registration. Two buttons for Signup and Login(login button will transfer the user to the LoginActivity).
4) ForgotPasswordActivity: This activity is used to send the forgot password link to the user to set a new password. The reset link will be sent to the user's email id.
Register a user with email and password :
To register a user with email and password, firstly, you have to declare an instance of FirebaseAuth.
Now, in the onCreate() method, initialize the FirebaseAuth instance.
auth = FirebaseAuth.getInstance()
To signup a user with email and password, we can take the help of createUserWithEmailAndPassword() method. This method takes email and password as a parameter, validates them and then create a new user.
auth.createUserWithEmailAndPassword(email, password).addOnCompleteListener(this, OnCompleteListener{ task -> if(task.isSuccessful){ Toast.makeText(this, "Successfully Registered", Toast.LENGTH_LONG).show() val intent = Intent(this, MainActivity::class.java) startActivity(intent) finish() }else { Toast.makeText(this, "Registration Failed", Toast.LENGTH_LONG).show() } })
That's it. Your user will be registered and you can see the registered user on the Firebase website under the Authentication section and then in the Users tab. If you are trying to register with the same email more than once, then you will receive an error or in simple words your task is unsuccessful.
Login a user with
email and password :
Now, we need to login the user by authenticating the email and password entered by the user.
Firstly, declare an instance of FirebaseAuth.
Now, in the onCreate() method,
initialize the FirebaseAuth instance.
auth =
FirebaseAuth.getInstance();
To signin a user with email and password, we have one method called signInWithEmailAndPassword(). This method takes email and password as a parameter, validates them and then signin a user in your application if the validation is successful.
Firstly, create an instance of FirebaseAuth.
Now, in the onCreate() method, initialize the FirebaseAuth instance.
Check your email, you have received a reset link.
Check if a user is logged in or not :
Screenshot
of Applications :
Logout the
user :
Now, we are done with the login, signup and
reset the password. Our next aim is to logout the user if it is already logged
in. To do so, we are having one method named signOut(). So,
just use this method to signout a user.
Closing notes :
In this blog, we learned how to use Firebase for login and
authentication in our application. Firebase provides a number of methods for
doing the authentication task in a very easier manner. So, to perform a login
or authentication task, you need to use those methods only. We saw how we can
use email and password to login into an application.
The project used in this blog is just for example purpose.
In general to have a better user experience and app performance, you should use
the modularization concept.
Hope you learned something new today.
Have a look at our Android tutorials.
Do share this blog with your fellow developers to spread the knowledge. You can read more blogs on Android on our blogging website.
Happy Learning :)
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