Implement Authentication system using Firebase

Firebase is also used for the authentication services like login and registration. Firebase Authentication provides easy methods. Before diving into the Firebase authentication service code, we need to enable the authentication from Firebase console.

From the console, select the Authentication tab and SIGN-IN METHOD and select method we want to use for sign-in users. We will select email/password method.

• We need to enable the Sign-In-Method under the Firebase Authentication part, as mentioned below.

• Click on save and you can now see that the Sign-In-Method with Email/Password is enabled as shown below.

Firebase: User Registration

We can easily add a registration method using firebase methods createUser. We will demonstrate this below:

Create a new Xcode project, and setup the Xcode project for using Firebase. If you are new to Firebase then please follow our previous article on Getting started with Firebase from the link here.

You can download the started project for the link here. This project is totally configured with Firebase SDK. you just need to add your GoogleServicesInfo.plist file to the project. By this way you are all set to run the project.

You can download the whole project from the link here.

We will create a simple UI in the project in order to Sign up the user.

• Navigate to Main.storyboard file and create 2 Buttons named Sign up and Sign in respectively.

 

•  Add IBActions for the 2 respective buttons will be created in the below steps.

• Add the below code snippet under the sign up method and the import statements in the file as well.
• As of now I have added my email id and dummy password for testing purpose.

 

//
//  ViewController.swift
//  MyFirstProject
//
//  Created by Chandra Rao on 25/03/18.
//  Copyright © 2018 Chandra Rao. All rights reserved.
//
import UIKit
import Firebase
import FirebaseAuth
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
@IBAction func btnSignInClicked(_ sender: Any) {
}
@IBAction func btnSignUpClicked(_ sender: Any) {
Auth.auth().createUser(withEmail: "chandraravi.2312@gmail.com", password: "EasySolutions@123", completion: { (user, error) in
if error != nil {
print(error!)
}else {
print ("Registration Successful!")
}
})
}
}

Compile and run the project.

• You can see in the console log is printed as “Registration Successful!”
• You can also see the list of registered users in the Firebase Console.

Note: If you try to sign up using the same Email id it will return the following error in the console.

Error Domain=FIRAuthErrorDomain Code=17007 “The email address is already in use by another account.” UserInfo={NSLocalizedDescription=The email address is already in use by another account., error_name=ERROR_EMAIL_ALREADY_IN_USE}

Firebase: User Login

• Add the below code snippet in the login method action.

 

//
//  ViewController.swift
//  MyFirstProject
//
//  Created by Chandra Rao on 25/03/18.
//  Copyright © 2018 Chandra Rao. All rights reserved.
//
import UIKit
import Firebase
import FirebaseAuth
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
@IBAction func btnSignInClicked(_ sender: Any) {
Auth.auth().signIn(withEmail: "chandraravi.2312@gmail.com", password: "EasySolutions@123", completion: { (user, error) in
if error != nil {
print(error!)
}else {
print("login successful")
}
})
}
@IBAction func btnSignUpClicked(_ sender: Any) {
Auth.auth().createUser(withEmail: "chandraravi.2312@gmail.com", password: "EasySolutions@123", completion: { (user, error) in
if error != nil {
print(error!)
}else {
print ("Registration Successful!")
}
})
}
}

• Here also we have given the same user email and password.
• Compile and run the project and see the result.

Firebase : User Sign out

We will add another button, in the UI in order to logout the user.

• Add a IBAction for this button and add the below code snippet.

 

@IBAction func btnLogoutClicked(_ sender: Any) {
do {
try Auth.auth().signOut()
}catch {
print(error)
print("error: there was a problem logging out")
}
}

 

And this is how we complete a end to end user flow. User Registration, User Login, User Logout.

We hope you liked the tutorials, you can download the whole project from the link here. You need to clone the branch named as “FirebaseAuth”.