FirebaseAuthentication.net is an unofficial C# implementation of Firebase Authentication and FirebaseUI.

The libraries provide a drop-in auth solution that handles the flows for signing in users with email addresses and passwords, Identity Provider Sign In including Google, Facebook, GitHub, Twitter, Apple, Microsoft and anonymous sign-in.

The solution consists of 5 libraries - a base one and 4 platform specific ones:

• FirebaseAuthentication.net targets .NET Standard 2.0
• FirebaseAuthentication.WPF targets WPF on .NET 6
• FirebaseAuthentication.UWP targets UWP with min version 19041
• FirebaseAuthentication.WinUI3 targets WinUI3
• FirebaseAuthentication.Maui targets Maui (TODO)

Either via Visual Studio Nuget package manager, or from command line:

# base package dotnet add package FirebaseAuthentication.net # Platform specific FirebaseUI (has dependency on base package) dotnet add package FirebaseAuthentication.WPF dotnet add package FirebaseAuthentication.UWP dotnet add package FirebaseAuthentication.WinUI3 dotnet add package FirebaseAuthentication.Maui

Use the --version option to specify a preview version to install.

Daily preview builds are also available on feedz.io. Just add the following Package Source to your Visual Studio:

https://f.feedz.io/step-up-labs/firebase/nuget/index.json 

In general the terminology and API naming conventions try to follow the official JavaScript implementation, adjusting it to fit the .NET conventions. E.g. signInWithCredential is called SignInWithCredentialAsync because it is meant to be awaited, but otherwise the terminology should be mostly the same.

There are currently 3 sample projects in the samples folder:

• .NET Core Console application (uses only the base library, no UI)
• WPF sample with UI
• UWP sample with UI
• WinUI3 sample with UI

Feel free to clone the repo and check them out, just don't forget to add your custom API keys and other setup (typically in Program.cs or App.xaml.cs).

For general Firebase setup, refer to the official documentation which discusses the general concepts and individual providers in detail. You might also want to check out the first two steps in this web documentation. Notice that Firebase doesn't officially support Windows as a platform so you will have to register your application as a web app in Firebase Console.

The base library gives you the same features as the official Firebase SDK Authentication, that is without any UI. Your entrypoint is the FirebaseAuthClient.

// main namespacesusingFirebase.Auth;usingFirebase.Auth.Providers;usingFirebase.Auth.Repository;// Configure...varconfig=newFirebaseAuthConfig{ApiKey="<API KEY>",AuthDomain="<DOMAIN>.firebaseapp.com",Providers=newFirebaseAuthProvider[]{// Add and configure individual providersnewGoogleProvider().AddScopes("email"),newEmailProvider()// ...},// WPF:UserRepository=newFileUserRepository("FirebaseSample")// persist data into %AppData%\FirebaseSample// UWP:UserRepository=newStorageRepository()// persist data into ApplicationDataContainer};// ...and create your FirebaseAuthClientvarclient=newFirebaseAuthClient(config);

Notice the UserRepository. This tells FirebaseAuthClient where to store the user's credentials. By default the libraries use in-memory repository; to preserve user's credentials between application runs, use FileUserRepository (or your custom implementation of IUserRepository).

After you have your client, you can sign-in or sign-up the user with any of the configured providers.

// anonymous sign invaruser=awaitclient.SignInAnonymouslyAsync();// sign up or sign in with email and passwordvaruserCredential=awaitclient.CreateUserWithEmailAndPasswordAsync("email","pwd","Display Name");varuserCredential=awaitclient.SignInWithEmailAndPasswordAsync("email","pwd");// sign in via provider specific AuthCredentialvarcredential=TwitterProvider.GetCredential("access_token","oauth_token_secret");varuserCredential=awaitclient.SignInWithCredentialAsync(credential);// sign in via web browser redirect - navigate to given uri, monitor a redirect to // your authdomain.firebaseapp.com/__/auth/handler// and return the whole redirect uri back to the client;// this method is actually used by FirebaseUIvaruserCredential=awaitclient.SignInWithRedirectAsync(provider,async uri =>{returnawaitOpenBrowserAndWaitForRedirectToAuthDomain(uri);});

As you can see the sign-in methods give you a UserCredential object, which contains an AuthCredential and a User objects. User holds details about a user as well as some useful methods, e.g. GetIdTokenAsync() to get a valid IdToken you can use as an access token to other Firebase API (e.g. Realtime Database).

// user and auth propertiesvaruser=userCredential.User;varuid=user.Uid;varname=user.Info.DisplayName;// more properties are available in user.InfovarrefreshToken=user.Credential.RefreshToken;// more properties are available in user.Credential// user methodsvartoken=awaituser.GetIdTokenAsync();awaituser.DeleteAsync();awaituser.ChangePasswordAsync("new_password");awaituser.LinkWithCredentialAsync(authCredential);

To sign out a user simply call

client.SignOut();

The platform specific UI libraries use the FirebaseAuthClient under the hood, but need to be initilized via the static Initialize method of FirebaseUI:

// Initialize FirebaseUI during your application startup (e.g. App.xaml.cs)FirebaseUI.Initialize(newFirebaseUIConfig{ApiKey="<API KEY>",AuthDomain="<DOMAIN>.firebaseapp.com",Providers=newFirebaseAuthProvider[]{newGoogleProvider().AddScopes("email"),newEmailProvider()// and others},PrivacyPolicyUrl="<PP URL>",TermsOfServiceUrl="<TOS URL>",IsAnonymousAllowed=true,UserRepository=newFileUserRepository("FirebaseSample")// persist data into %AppData%\FirebaseSample});

Notice the UserRepository. This tells FirebaseUI where to store the user's credentials. By default the libraries use in-memory repository; to preserve user's credentials between application runs, use FileUserRepository (or your custom implementation of IUserRepository).

FirebaseUI comes with FirebaseUIControl you can use in your xaml as follows:

<!--WPF Sample--> <Pagex:Class="Firebase.Auth.Wpf.Sample.LoginPage"xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"xmlns:d="http://schemas.microsoft.com/expression/blend/2008"xmlns:firebase="clr-namespace:Firebase.Auth.UI;assembly=Firebase.Auth.UI.WPF"mc:Ignorable="d"d:DesignHeight="450"d:DesignWidth="800"> <Grid> <firebase:FirebaseUIControl> <firebase:FirebaseUIControl.Header> <!--Custom content shown above the provider buttons--> <ImageHeight="150"Source="/Assets/firebase.png" /> </firebase:FirebaseUIControl.Header> </firebase:FirebaseUIControl> </Grid> </Page>

Toggling the visibility of this UI control is up to you, depending on your business logic. E.g. you could show it as a popup, or a Page inside a Frame etc. You would typically want to toggle the control's visibility in response to the AuthStateChanged event:

// subscribe to auth state changesFirebaseUI.Instance.Client.AuthStateChanged+=this.AuthStateChanged;privatevoidAuthStateChanged(objectsender,UserEventArgse){// the callback is not guaranteed to be on UI threadApplication.Current.Dispatcher.Invoke(()=>{if(e.User==null){// no user is signed in (first run of the app, user signed out..), show login UI this.ShowLoginUI();}elseif(this.loginUIShowing){// user signed in (or was already signed in), hide the login UI// this event can be raised multiple times (e.g. when access token gets refreshed), you need to be ready for thatthis.HideLoginUI();}});}