Firebase UI Auth Provider iOS Swift Example

Question

I am starting a new iOS Swift application and want to use FirebaseUI Auth. Here is the link to the docs where it talks about it under Drop-in authentication solution Firebase Auth. The FirebaseUI Auth for Android was very simple and easy. It appears that the iOS examples are out of date as there API seems to have changed drastically between versions. It looks like they are on version 3.1.

The directions are also a little bare: https://github.com/firebase/FirebaseUI-iOS

Can someone please help me out and provide an example AppDelegate and ViewController for facebook and google login?

I am using Xcode 8.3, Swift 3.

Podfile:

# Uncomment the next line to define a global platform for your project
platform :ios, '9.0'

target 'Project' do
  # Comment the next line if you're not using Swift and don't want to use dynamic frameworks
  use_frameworks!

  pod 'FirebaseUI', '~> 3.1'
  pod 'Firebase/Core'
  pod 'Firebase/Database'
  pod 'Firebase/Crash'
  pod 'Firebase/Auth'
  pod 'Firebase/Storage'
  pod 'GoogleSignIn'
  pod 'FBSDKLoginKit'


  target 'ProjectTests' do
    inherit! :search_paths
    # Pods for testing
  end

  target 'ProjectUITests' do
    inherit! :search_paths
    # Pods for testing
  end

end

Here is my AppDelegate

import UIKit
import CoreData
import Firebase
import FirebaseAuthUI
import FirebaseAuth
import GoogleSignIn
import FBSDKLoginKit

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
    // Override point for customization after application launch.
    FIRApp.configure()
    return true
}

func applicationWillResignActive(_ application: UIApplication) {
    // Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
    // Use this method to pause ongoing tasks, disable timers, and invalidate graphics rendering callbacks. Games should use this method to pause the game.
}

func applicationDidEnterBackground(_ application: UIApplication) {
    // Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
    // If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}

func applicationWillEnterForeground(_ application: UIApplication) {
    // Called as part of the transition from the background to the active state; here you can undo many of the changes made on entering the background.
}

func applicationDidBecomeActive(_ application: UIApplication) {
    // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}

}

Here is my ViewController

import UIKit
import Firebase
import FirebaseAuth
import FirebaseAuthUI
import FirebaseDatabaseUI
import FirebaseGoogleAuthUI
import FirebaseFacebookAuthUI
import FBSDKCoreKit
import FBSDKLoginKit

class ViewController: UIViewController, FUIAuthDelegate {

    var kFacebookAppID = "111111111111111"
override func viewDidLoad() {
    super.viewDidLoad()

    //FIRApp.configure()
    checkLoggedIn()
}

func checkLoggedIn() {
    FIRAuth.auth()?.addStateDidChangeListener { auth, user in
        if user != nil {
            // User is signed in.
        } else {
            // No user is signed in.
            self.login()
        }
    }
}

func login() {
    let authUI = FUIAuth.defaultAuthUI()
    let facebookProvider = FUIGoogleAuth()
    let googleProvider = FUIFacebookAuth()
    authUI?.delegate = self
    authUI?.providers = [googleProvider, facebookProvider]
    let authViewController = authUI?.authViewController()
    self.present(authViewController!, animated: true, completion: nil)
}

@IBAction func logoutUser(_ sender: AnyObject) {
    try! FIRAuth.auth()!.signOut()
}

func authUI(_ authUI: FUIAuth, didSignInWith user: FIRUser?, error: Error?) {
    if error != nil {
        //Problem signing in
        login()
    }else {
        //User is in! Here is where we code after signing in

    }
}
}

Answer 1

You're very close! Wei Jay was right in that you need to define your URL schemes inside your apps Info.plist file, and add the callback in your app delegate.

Essentially you need to add the below to the root of the plist.

<key>CFBundleURLTypes</key>
<array>
    <dict>
        <key>CFBundleURLSchemes</key>
        <array>
            <string>com.googleusercontent.apps.{app-id-here}</string>
        </array>
    </dict>
    <dict>
        <key>CFBundleURLSchemes</key>
        <array>
            <string>fb{app-id-here}</string>
        </array>
    </dict>
</array>
<key>FacebookAppID</key>
<string>{app-id-here}</string>
<key>FacebookDisplayName</key>
<string>{name-here}</string>
<key>LSApplicationQueriesSchemes</key>
<array>
    <string>fbauth2</string>
</array>

You can get your google app id from the RESERVED_CLIENT_ID entry in your GoogleService-Info.plist file.

Next, my AppDelegate file just implements the openURL delegate method:

func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {

    let googleSignIn = GIDSignIn.sharedInstance().handle(url, sourceApplication: options[UIApplicationOpenURLOptionsKey.sourceApplication] as? String, annotation: options[UIApplicationOpenURLOptionsKey.annotation])

    let facebookSignIn = FBSDKApplicationDelegate.sharedInstance().application(app, open: url, sourceApplication: options[UIApplicationOpenURLOptionsKey.sourceApplication] as? String, annotation: options[UIApplicationOpenURLOptionsKey.annotation])

    return googleSignIn || facebookSignIn
}

Explaination here for how to set up settings for Facebook

This dude here has provided a nice example of his implementation of Firebase Auth UI

Answer 2

Your code seems fine! To communicate with Google/Facebook/Twitter Auth, you must add support for a URL Scheme to your app. CHECK THIS OUT!

func configureAuth() {
    // TODO: configure firebase authentication
    let provider: [FUIAuthProvider] = [FUIGoogleAuth(), FUIFaceBookAuth()]
    FUIAuth.defaultAuthUI()?.providers = provider 

    // listen for changes in the authorization state
    _authHandle = FIRAuth.auth()?.addStateDidChangeListener { (auth: FIRAuth, user: FIRUser?) in

        // check if there is a current user
        if let activeUser = user {
            // check if current app user is the current FIRUser
            if self.user != activeUser {
                // sign in
            }
        } else {
            // user must sign in
            self.loginSession()
        }
    }


}

func loginSession() {
    let authViewController = FUIAuth.defaultAuthUI()!.authViewController()
    self.present(authViewController, animated: true, completion: nil)
}