How to use FirebaseUI for Google authentication on iOS in Swift?

Question

I\'m following https://firebase.google.com/docs/auth/ and want to use FirebaseUI (https://github.com/firebase/FirebaseUI-iOS/tree/master/FirebaseUI) for authentication.

Answer 1

I haven't tried this solution but this StackOverflow problem was linked to the FirebaseUI repo's issues section and someone there responded;

Obj-C: "There's a bug that prevents [[FIRAuthUI authUI] authViewController] from being used as the root view controller of your app. The workaround is to use a placeholder view controller as your app's root view controller, then present [[FIRAuthUI authUI] authViewController] on top of it."

for Swift users: There's a bug that prevents FIRAuthUI.authUI().authViewController() from being used as the root view controller of your app. The workaround is to use a placeholder view controller as your app's root view controller, then present FIRAuthUI.authUI().authViewController() on top of it.

Link: https://github.com/firebase/FirebaseUI-iOS/issues/65

Answer 2

Is your AppDelegate a FIRAuthUIDelegate?

Anyway, instead of using delegates, you can make use of FIRAuth listener: func addAuthStateDidChangeListener(listener: FIRAuthStateDidChangeListenerBlock) -> FIRAuthStateDidChangeListenerHandle

You can use it this way:

FIRAuth.auth()?.addAuthStateDidChangeListener {

    (auth, user) in

    if user != nil {

        print("user signed in")

    }

}

You can see a working sample on https://github.com/cooliopas/FirebaseAuth-Demo

Its in spanish, but I'm sure you will understand the code.

Answer 3

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.your-app-id</string>
        </array>
    </dict>
</array>

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

Next, you will need to implement the openURL app delegate method like this:

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

    return GIDSignIn.sharedInstance().handle(url, sourceApplication: options[UIApplicationOpenURLOptionsKey.sourceApplication] as? String, annotation: options[UIApplicationOpenURLOptionsKey.annotation])
}

Check out my answer here for some more details.