### Setup UIKit Data Binding Sample Project

Source: https://github.com/firebase/firebaseui-ios/blob/main/README.md

Navigate to a UIKit data binding sample directory (Database, Firestore, or Storage) and run `pod install`.

```bash
$ cd FirebaseDatabaseUI # or FirebaseFirestoreUI, FirebaseStorageUI
$ pod install
```

--------------------------------

### Install FirebaseUI with CocoaPods

Source: https://github.com/firebase/firebaseui-ios/blob/main/samples/objc/README.md

Clone the repository, navigate to the sample directory, install dependencies using CocoaPods, and open the workspace.

```bash
git clone https://github.com/firebase/FirebaseUI-iOS.git
cd FirebaseUI-iOS/samples/objc
pod install
open FirebaseUI-demo-objc.xcworkspace
```

--------------------------------

### Setup SwiftUI Sample Project

Source: https://github.com/firebase/firebaseui-ios/blob/main/README.md

Navigate to the SwiftUI sample directory and open the Xcode project for SwiftUI components.

```bash
$ cd samples/swiftui/FirebaseSwiftUISample
$ open FirebaseSwiftUISample.xcodeproj
```

--------------------------------

### Full-Featured Authentication Example in SwiftUI

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Configure and use AuthService with multiple sign-in providers, email link, MFA, and TOS/privacy policy URLs. This example sets up the authentication service and presents the AuthPickerView to manage the authentication state.

```swift
import FirebaseAppleSwiftUI
import FirebaseAuthSwiftUI
import FirebaseFacebookSwiftUI
import FirebaseGoogleSwiftUI
import FirebaseOAuthSwiftUI
import FirebasePhoneAuthSwiftUI
import FirebaseTwitterSwiftUI
import SwiftUI

struct ContentView: View {
  let authService: AuthService

  init() {
    // Configure email link sign-in
    let actionCodeSettings = ActionCodeSettings()
    actionCodeSettings.handleCodeInApp = true
    actionCodeSettings.url = URL(string: "https://yourapp.firebaseapp.com")
    actionCodeSettings.setIOSBundleID(Bundle.main.bundleIdentifier!)
    
    // Create configuration with options
    let configuration = AuthConfiguration(
      shouldAutoUpgradeAnonymousUsers: true,
      tosUrl: URL(string: "https://example.com/tos"),
      privacyPolicyUrl: URL(string: "https://example.com/privacy"),
      emailLinkSignInActionCodeSettings: actionCodeSettings,
      mfaEnabled: true
    )

    // Initialize AuthService with multiple providers
    authService = AuthService(configuration: configuration)
      .withEmailSignIn()
      .withAppleSignIn()
      .withGoogleSignIn()
      .withFacebookSignIn()
      .withPhoneSignIn()
      .withTwitterSignIn()
      .withOAuthSignIn(OAuthProviderSwift.github())
      .withOAuthSignIn(OAuthProviderSwift.microsoft())
      .withOAuthSignIn(OAuthProviderSwift.yahoo())
  }

  var body: some View {
    AuthPickerView { // This view handles the presentation of the authentication UI
      authenticatedContent
    }
    .environment(authService) // Inject the authService into the environment
  }

  var authenticatedContent: some View {
    NavigationStack {
      VStack(spacing: 20) {
        if authService.authenticationState == .authenticated {
          Text("Authenticated")
          
          Button("Manage Account") {
            authService.isPresented = true
          }
          .buttonStyle(.bordered)
          
          Button("Sign Out") {
            Task {
              try? await authService.signOut()
            }
          }
          .buttonStyle(.borderedProminent)
        } else {
          Text("Not Authenticated")
          
          Button("Sign In") {
            authService.isPresented = true
          }
          .buttonStyle(.borderedProminent)
        }
      }
      .navigationTitle("My App")
    }
    .onChange(of: authService.authenticationState) { _, newValue in
      // Automatically show auth UI when not authenticated
      if newValue != .authenticating {
        authService.isPresented = (newValue == .unauthenticated)
      }
    }
  }
}
```

--------------------------------

### Clone and Install FirebaseUI Swift

Source: https://github.com/firebase/firebaseui-ios/blob/main/samples/swift/README.md

Clone the FirebaseUI-iOS repository, navigate to the Swift samples directory, install CocoaPods dependencies, and open the workspace.

```bash
git clone https://github.com/firebase/FirebaseUI-iOS.git
cd FirebaseUI-iOS/samples/swift
pod install
open FirebaseUI-demo-swift.xcworkspace
```

--------------------------------

### Using the Default Table/Collection View Cell

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseDatabaseUI/README.md

Demonstrates how to use default UITableViewCell or UICollectionViewCell implementations for quick setup.

```APIDOC
## Swift (UITableViewCell)
```swift
self.dataSource = self.tableView.bind(to: firebaseRef) { tableView, indexPath, snap in
  let cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier", for: indexPath)
  // Populate cell as you see fit, like as below
  cell.textLabel?.text = snap.key
  return cell
}
```

## Swift (UICollectionViewCell)
```swift
self.dataSource = self.collectionView.bind(to: firebaseRef) { collectionView, indexPath, snap in
  let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "reuseIdentifier", for: indexPath)
  // Populate cell as you see fit
  cell.contentView.accessibilityLabel = "A cell"
  return cell
}
```
```

--------------------------------

### Start MFA Enrollment

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Initiates the enrollment process for a second factor (SMS or TOTP). Requires MFA to be enabled in the AuthConfiguration.

```APIDOC
## Start MFA Enrollment

### Description
Initiates enrollment for a second factor.

### Method
`startMfaEnrollment`

### Parameters
- `type` (SecondFactorType) - Required - Type of second factor (`.sms` or `.totp`)
- `accountName` (String?) - Optional - Account name for TOTP (defaults to user's email)
- `issuer` (String?) - Optional - Issuer name for TOTP (defaults to `configuration.mfaIssuer`)

### Returns
`EnrollmentSession` - Containing enrollment information

### Throws
`AuthServiceError` - If MFA is not enabled or factor type not allowed

### Requirements
`mfaEnabled` must be `true` in `AuthConfiguration`
```

--------------------------------

### Custom Google Provider Button Example

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Implement a fully custom button for Google Sign-In by conforming to AuthProviderUI. This allows complete control over the button's appearance and behavior.

```swift
import FirebaseAuthSwiftUI
import FirebaseGoogleSwiftUI
import FirebaseAppleSwiftUI
import SwiftUI

// Custom Google Provider UI
class CustomGoogleProviderAuthUI: AuthProviderUI {
  private let typedProvider: GoogleProviderSwift
  var provider: AuthProviderSwift { typedProvider }
  let id: String = "google.com"
  
  init() {
    typedProvider = GoogleProviderSwift()
  }
  
  @MainActor func authButton() -> AnyView {
    AnyView(CustomGoogleButton(provider: typedProvider))
  }
}

struct CustomGoogleButton: View {
  let provider: GoogleProviderSwift
  @Environment(AuthService.self) private var authService
  
  var body: some View {
    Button {
      Task {
        try? await authService.signIn(provider)
      }
    } label: {
      HStack {
        Image(systemName: "g.circle.fill")
        Text("My Custom Google Button")
      }
      .frame(maxWidth: .infinity)
      .padding()
      .background(Color.purple) // Your custom color
      .foregroundColor(.white)
      .cornerRadius(10)
    }
  }
}

// Then use it
struct ContentView: View {
  let authService: AuthService
  
  init() {
    let configuration = AuthConfiguration()
    authService = AuthService(configuration: configuration)
      .withAppleSignIn() // Use default Apple button
    
    // Use custom Google button
    authService.registerProvider(
      providerWithButton: CustomGoogleProviderAuthUI()
    )
  }
  
  var body: some View {
    AuthPickerView {
      Text("App Content")
    }
    .environment(authService)
  }
}
```

--------------------------------

### Minimal FirebaseUI AuthPickerView Example

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Integrate AuthPickerView for a minimal email authentication flow. Ensure the AuthService is configured and provided to the environment.

```swift
import FirebaseAuthSwiftUI
import SwiftUI

struct ContentView: View {
  let authService: AuthService

  init() {
    let configuration = AuthConfiguration()
    
    authService = AuthService(configuration: configuration)
      .withEmailSignIn()
  }

  var body: some View {
    AuthPickerView {
      // Your authenticated app content goes here
      Text("Welcome to your app!")
    }
    .environment(authService)
  }
}
```

--------------------------------

### Start MFA Enrollment

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Initiates enrollment for a second factor (SMS or TOTP). Requires `mfaEnabled` to be true in `AuthConfiguration`. Account name and issuer are optional for TOTP.

```swift
public func startMfaEnrollment(
  type: SecondFactorType,
  accountName: String? = nil,
  issuer: String? = nil
) async throws -> EnrollmentSession
```

--------------------------------

### Install FirebaseUI Storage with CocoaPods

Source: https://github.com/firebase/firebaseui-ios/blob/main/README.md

Use this snippet to include only Storage features when using CocoaPods for UIKit data binding.

```ruby
pod 'FirebaseUI/Storage'
```

--------------------------------

### Install FirebaseUI Database with CocoaPods

Source: https://github.com/firebase/firebaseui-ios/blob/main/README.md

Use this snippet to include only Database features when using CocoaPods for UIKit data binding.

```ruby
pod 'FirebaseUI/Database'
```

--------------------------------

### Custom SwiftUI Authentication Flow

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Implement a custom authentication flow using SwiftUI and FirebaseUI's AuthService. This example demonstrates setting up navigation, handling sign-in with Google and phone, and managing authentication states.

```swift
import FirebaseAuth
import FirebaseAuthSwiftUI
import FirebaseGoogleSwiftUI
import SwiftUI

enum CustomAuthRoute {
  case signIn
  case phoneVerification
  case mfaResolution
}

struct ContentView: View {
  private let authService: AuthService
  @State private var navigationPath: [CustomAuthRoute] = []
  @State private var errorMessage: String?

  init() {
    let configuration = AuthConfiguration()
    self.authService = AuthService(configuration: configuration)
      .withGoogleSignIn()
      .withPhoneSignIn()
  }

  var body: some View {
    NavigationStack(path: $navigationPath) {
      Group {
        if authService.authenticationState == .authenticated {
          authenticatedView
        } else {
          customSignInView
        }
      }
      .navigationDestination(for: CustomAuthRoute.self) {
        route in
        switch route {
        case .signIn:
          customSignInView
        case .phoneVerification:
          customPhoneVerificationView
        case .mfaResolution:
          customMFAView
        }
      }
    }
    .environment(authService)
    .alert("Error", isPresented: .constant(errorMessage != nil)) {
      Button("OK") {
        errorMessage = nil
      }
    } message: {
      Text(errorMessage ?? "")
    }
  }

  var customSignInView: some View {
    VStack(spacing: 20) {
      Text("Custom Sign In")
        .font(.title)
      
      Button("Sign in with Google") {
        Task {
          do {
            let provider = GoogleProviderSwift(clientID: Auth.auth().app?.options.clientID ?? "")
            let outcome = try await authService.signIn(provider)
            
            // Handle MFA if required
            if case .mfaRequired = outcome {
              navigationPath.append(.mfaResolution)
            }
          } catch {
            errorMessage = error.localizedDescription
          }
        }
      }
      .buttonStyle(.borderedProminent)
      
      Button("Phone Sign In") {
        navigationPath.append(.phoneVerification)
      }
      .buttonStyle(.bordered)
    }
    .padding()
  }

  var customPhoneVerificationView: some View {
    Text("Custom Phone Verification View")
    // Implement your custom phone auth UI here
  }

  var customMFAView: some View {
    Text("Custom MFA Resolution View")
    // Implement your custom MFA UI here
  }

  var authenticatedView: some View {
    VStack(spacing: 20) {
      Text("Welcome!")
      Text("Email: \(authService.currentUser?.email ?? "N/A")")
      
      Button("Sign Out") {
        Task {
          try? await authService.signOut()
        }
      }
      .buttonStyle(.borderedProminent)
    }
  }
}
```

--------------------------------

### Install FirebaseUI Firestore with CocoaPods

Source: https://github.com/firebase/firebaseui-ios/blob/main/README.md

Use this snippet to include only Firestore features when using CocoaPods for UIKit data binding.

```ruby
pod 'FirebaseUI/Firestore'
```

--------------------------------

### Create Custom Twitter Button UI with Firebase

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Implement a custom button for Twitter sign-in using `AuthProviderUI`. This example shows how to create a custom button view, wrap it in an `AuthProviderUI` class, and register it with `AuthService` for use in your application.

```swift
import FirebaseAuthSwiftUI
import FirebaseTwitterSwiftUI
import SwiftUI

// Step 1: Create your custom button view
struct CustomTwitterButton: View {
  let provider: TwitterProviderSwift
  @Environment(AuthService.self) private var authService
  @Environment(\.mfaHandler) private var mfaHandler

  var body: some View {
    Button {
      Task {
        do {
          let outcome = try await authService.signIn(provider)

          // Handle MFA if required
          if case let .mfaRequired(mfaInfo) = outcome,
             let onMFA = mfaHandler {
            onMFA(mfaInfo)
          }
        } catch {
          // Do Something Else
        }
      }
    } label: {
      HStack { // Your custom icon
        Text("Sign in with Twitter")
          .fontWeight(.semibold)
      }
      .frame(maxWidth: .infinity)
      .padding()
      .background(
        LinearGradient(
          colors: [Color.blue, Color.cyan],
          startPoint: .leading,
          endPoint: .trailing
        )
      )
      .foregroundColor(.white)
      .cornerRadius(12)
      .shadow(radius: 4)
    }
  }
}

// Step 2: Create a custom AuthProviderUI wrapper
class CustomTwitterProviderAuthUI: AuthProviderUI {
  private let typedProvider: TwitterProviderSwift
  var provider: AuthProviderSwift { typedProvider }
  let id: String = "twitter.com"

  init(provider: TwitterProviderSwift = TwitterProviderSwift()) {
    typedProvider = provider
  }

  @MainActor func authButton() -> AnyView {
    AnyView(CustomTwitterButton(provider: typedProvider))
  }
}

// Step 3: Use it in your app
struct ContentView: View {
  let authService: AuthService

  init() {
    let configuration = AuthConfiguration()
    authService = AuthService(configuration: configuration)

    // Register your custom provider UI
    authService.registerProvider(
      providerWithButton: CustomTwitterProviderAuthUI()
    )
    authService.isPresented = true
  }

  var body: some View {
    AuthPickerView { 
      usersApp
    }
    .environment(authService)
  }

  var usersApp: some View {
    NavigationStack {
      VStack {
        Button {
          authService.isPresented = true
        } label: {
          Text("Authenticate")
        }
      }
    }
  }
}

```

--------------------------------

### Configure Firebase App Entry Point

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Set up your app's entry point to configure Firebase. This involves creating an AppDelegate to handle application launch and ensuring FirebaseApp.configure() is called.

```swift
import FirebaseAuthSwiftUI
import FirebaseCore
import SwiftUI

class AppDelegate: NSObject, UIApplicationDelegate {
  func application(
    _ application: UIApplication,
    didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
  ) -> Bool {
    FirebaseApp.configure()
    return true
  }
}

@main
struct YourApp: App {
  @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate

  var body: some Scene {
    WindowGroup {
      ContentView()
    }
  }
}
```

--------------------------------

### Create User with Email and Password

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Creates a new user account using the provided email address and password. This method throws errors if user creation fails.

```swift
try await authService.createUser(email: "newuser@example.com", password: "securepassword")
```

--------------------------------

### AuthService Initialization

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Initializes the AuthService with optional custom configuration and a Firebase Auth instance.

```swift
public init(
  configuration: AuthConfiguration = AuthConfiguration(),
  auth: Auth = Auth.auth()
)
```

--------------------------------

### Sign In with Email and Password

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Signs in a user using their email address and password. This method throws errors if authentication fails.

```swift
try await authService.signIn(email: "user@example.com", password: "password123")
```

--------------------------------

### Bind UICollectionView to Firebase Reference (Swift)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseDatabaseUI/README.md

Use FUICollectionViewDataSource to automatically bind a Firebase reference to a UICollectionView. This example shows how to dequeue and populate cells.

```swift
self.dataSource = self.collectionView.bind(to: self.firebaseRef) { collectionView, indexPath, snap in
  let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "reuseIdentifier", for: indexPath)
  /* populate cell */
  return cell
}
```

--------------------------------

### Sign in with Google

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Enables Sign in with Google authentication and registers a Google button. An optional provider can be supplied.

```APIDOC
## withGoogleSignIn

### Description
Enables Sign in with Google authentication and will register a Google button that is rendered in AuthPickerView (default Views) or can be rendered in custom Views by calling `AuthService.renderButtons()`.

### Method Signature
```swift
// Available when importing FirebaseGoogleSwiftUI
public func withGoogleSignIn(_ provider: GoogleProviderSwift? = nil) -> AuthService
```

### Parameters
#### Path Parameters
- **provider** (`GoogleProviderSwift?`) - Optional - An optional instance of `GoogleProviderSwift`. If not provided, a default instance will be created using the client ID from Firebase configuration.

### Example
```swift
authService
  .withGoogleSignIn()
```
```

--------------------------------

### Bind UITableView to Firebase Query (Swift)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseDatabaseUI/README.md

Use FUITableViewDataSource to automatically bind a Firebase query to a UITableView. This example shows how to dequeue and populate cells.

```swift
self.dataSource = self.tableView.bind(to: query) { tableView, indexPath, snapshot in
  // Dequeue cell
  let cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier", for: indexPath)
  /* populate cell */
  return cell
}
```

--------------------------------

### Placeholder for Reproducing Problem Code

Source: https://github.com/firebase/firebaseui-ios/blob/main/ISSUE_TEMPLATE.md

Use this section to provide code that helps reproduce the issue you are experiencing. Ensure it is concise and directly related to the problem.

```swift
// TODO(you): code here to reproduce the problem
```

--------------------------------

### Bind UICollectionView to Firebase Reference (Objective-C)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseDatabaseUI/README.md

Use FUICollectionViewDataSource to automatically bind a Firebase reference to a UICollectionView in Objective-C. This example shows how to dequeue and populate cells.

```objectivec
self.firebaseRef = [[FIRDatabase database] reference];
self.dataSource = [self.collectionView bindToQuery:self.firebaseRef
                                      populateCell:^UICollectionViewCell *(UICollectionView *collectionView,
                                                                           NSIndexPath *indexPath,
                                                                           FIRDataSnapshot *object) {
  UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"reuseIdentfier"
                                                                    forIndexPath:indexPath];
  /* populate cell */
  return cell;
}];
```

--------------------------------

### Create User with Email/Password

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Creates a new user account using the provided email address and password.

```APIDOC
## createUser

### Description
Creates a new user account with email and password.

### Method Signature
```swift
public func createUser(email email: String, password: String) async throws -> SignInOutcome
```

### Parameters
- `email` (String): New user's email address.
- `password` (String): New user's password.

### Returns
`SignInOutcome`.

### Throws
`AuthServiceError` or Firebase Auth errors.
```

--------------------------------

### Bind UITableView to Firebase Query (Objective-C)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseDatabaseUI/README.md

Use FUITableViewDataSource to automatically bind a Firebase query to a UITableView in Objective-C. This example shows how to dequeue and populate cells.

```objectivec
self.dataSource = [self.tableView bindToQuery:query
                                 populateCell:^UITableViewCell *(UITableView *tableView,
                                                                 NSIndexPath *indexPath,
                                                                 FIRDataSnapshot *snap) {
  UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"reuseIdentifier"
                                                          forIndexPath:indexPath];
  /* populate cell */
  return cell;
}];
```

--------------------------------

### Sign in with Apple

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Enables Sign in with Apple authentication and registers an Apple button. An optional provider can be supplied.

```APIDOC
## withAppleSignIn

### Description
Enables Sign in with Apple authentication and will register an apple button that is rendered in `AuthPickerView` (default Views) or can be rendered in custom Views by calling `AuthService.renderButtons()`.

### Method Signature
```swift
// Available when importing FirebaseAppleSwiftUI
public func withAppleSignIn(_ provider: AppleProviderSwift? = nil) -> AuthService
```

### Parameters
#### Path Parameters
- **provider** (`AppleProviderSwift?`) - Optional - An optional instance of `AppleProviderSwift`. If not provided, a default instance will be created.

### Example
```swift
authService
  .withAppleSignIn()
```
```

--------------------------------

### Use Default UICollectionViewCell with Firebase Data (Swift)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseDatabaseUI/README.md

Bind a Firebase reference to a UICollectionView using the default UICollectionViewCell. This example sets the accessibility label for the cell's contentView.

```swift
self.dataSource = self.collectionView.bind(to: firebaseRef) { collectionView, indexPath, snap in
  let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "reuseIdentifier", for: indexPath)
  // Populate cell as you see fit
  cell.contentView.accessibilityLabel = "A cell"
  return cell
}
```

--------------------------------

### Use Default UITableViewCell with Firebase Data (Swift)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseDatabaseUI/README.md

Bind a Firebase reference to a UITableView using the default UITableViewCell. This example populates the cell's textLabel with the snapshot key.

```swift
self.dataSource = self.tableView.bind(to: firebaseRef) { tableView, indexPath, snap in
  let cell = tableView.dequeueReusableCell(withIdentifier: "reuseIdentifier", for: indexPath)
  // Populate cell as you see fit, like as below
  cell.textLabel?.text = snap.key
  return cell
}
```

--------------------------------

### Configure Generic OAuth Providers

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Enables authentication with generic OAuth/OIDC providers. Use this to add built-in providers like GitHub, Microsoft, Yahoo, or custom ones.

```swift
authService
  .withOAuthSignIn(OAuthProviderSwift.github())
  .withOAuthSignIn(OAuthProviderSwift.microsoft())
  .withOAuthSignIn(
    OAuthProviderSwift(
      providerId: "oidc.custom-provider",
      displayName: "Sign in with Custom",
      buttonIcon: Image("custom-logo"),
      buttonBackgroundColor: .blue,
      buttonForegroundColor: .white
    )
  )
```

--------------------------------

### Progressive Image Loading (Objective-C)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseStorageUI/README.md

Enable progressive downloading and decoding for images loaded from Cloud Storage using FIRStorageReference. This can improve perceived performance by displaying a low-resolution version of the image while the full image downloads.

```objective-c
// Use progressive downloading and decoding for images
[imageView sd_setImageWithStorageReference:reference placeholderImage:placeholderImage options:SDWebImageProgressiveLoad];
```

--------------------------------

### Override UI Strings with Localizable.strings

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

To customize UI text, create a Localizable.strings file and provide your own translations. Use the customStringsBundle parameter in AuthConfiguration to load these strings.

```swift
// Localizable.strings
"Sign in with Firebase" = "Welcome Back!";

// In your app configuration
let configuration = AuthConfiguration(customStringsBundle: .main)
```

--------------------------------

### Load Image from gs:// URL (Objective-C)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseStorageUI/README.md

Load an image directly from a gs:// URL using StorageImageLoader with SDWebImage. This is useful when you have the storage URL readily available. A placeholder image can be provided.

```objective-c
// Use gs:// URL directly with StorageImageLoader
NSURL *storageUrl = [NSURL URLWithString:@"gs://..."];
[imageView sd_setImageWithURL:storageUrl placeholderImage:placeholderImage options:0 context:@{SDWebImageContextImageLoader : FUIStorageImageLoader.sharedLoader}];
```

--------------------------------

### Sign In with Phone Number

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Signs in using a phone number and verification code.

```APIDOC
## signInWithPhoneNumber

### Description
Signs in using a phone number and verification code.

### Method Signature
```swift
public func signInWithPhoneNumber(
  verificationID: String,
  verificationCode: String
) async throws
```

### Parameters
- `verificationID` (String) - The verification ID returned from `verifyPhoneNumber()`
- `verificationCode` (String) - The SMS code received by the user

### Throws
- `AuthServiceError` or Firebase Auth errors
```

--------------------------------

### Run SwiftUI Auth Checks Locally

Source: https://github.com/firebase/firebaseui-ios/blob/main/CONTRIBUTING.md

Execute the SwiftUI Auth GitHub Actions workflow locally. This script runs package unit tests, integration tests, and UI tests by default. Use flags like --unit, --integration, or --ui to run specific checks. Include --lint to run lint-swift.sh beforehand.

```bash
./swiftui-tests.sh
```

```bash
./swiftui-tests.sh --unit
```

```bash
./swiftui-tests.sh --integration --ui
```

```bash
./swiftui-tests.sh --lint --all
```

```bash
./swiftui-tests.sh --device "iPhone 17 Pro" --ui
```

```bash
FIREBASE_PROJECT="my-firebase-project" ./swiftui-tests.sh --integration
```

--------------------------------

### Sign In with Email/Password

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Authenticates a user using their email address and password.

```APIDOC
## signIn (email:password:)

### Description
Signs in using email and password credentials.

### Method Signature
```swift
public func signIn(email: String, password: String) async throws -> SignInOutcome
```

### Parameters
- `email` (String): User's email address.
- `password` (String): User's password.

### Returns
`SignInOutcome`.

### Throws
`AuthServiceError` or Firebase Auth errors.
```

--------------------------------

### Handle Sign-In Link

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Handles the email link flow when the user taps the link. Automatically routes to either sign-in or reauthentication based on the current context.

```APIDOC
## handleSignInLink

### Description
Handles the email link flow when the user taps the link. Automatically routes to either sign-in or reauthentication based on the current context.

### Method Signature
```swift
public func handleSignInLink(url url: URL) async throws
```

### Parameters
- `url` (URL) - The deep link URL from the email

### Throws
- `AuthServiceError` or Firebase Auth errors

### Notes
This method handles both initial sign-in and reauthentication flows automatically. The behavior is determined by whether `sendEmailSignInLink(email:isReauth:)` was called with `isReauth: true`.
```

--------------------------------

### AuthPickerView

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

A pre-built SwiftUI view that provides a complete authentication UI, including MFA flows.

```APIDOC
### AuthPickerView

A pre-built view that provides complete authentication UI.

```swift
public struct AuthPickerView<Content: View>: View {
  public init(@ViewBuilder content: @escaping () -> Content = { EmptyView() })
}
```

**Parameters:**
- `content`: Your app's authenticated content, shown when user is signed in.

**Usage:**

```swift
AuthPickerView {
  // Your app content here
  Text("Welcome!")
}
.environment(authService)
```

**Behavior:**
- Presents authentication UI as a modal sheet controlled by `authService.isPresented`
- Automatically handles navigation between auth screens
- Includes built-in error handling and account conflict resolution
- Supports MFA flows automatically
```

--------------------------------

### Load Image from gs:// URL (Swift)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseStorageUI/README.md

Load an image directly from a gs:// URL using StorageImageLoader with SDWebImage in Swift. This is useful when the storage URL is readily available. A placeholder image can be provided.

```swift
// Use gs:// URL directly with StorageImageLoader
let storageUrl = URL(string: "gs://...")
imageView.sd_setImage(with: storageUrl, placeholderImage: placeholderImage, options:[], context: [.imageLoader : StorageImageLoader.shared])
```

--------------------------------

### Initialize FUIArray (Swift)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseDatabaseUI/README.md

Initialize an FUIArray to synchronize a Firebase FIRDatabaseReference with an array in Swift.

```swift
let firebaseRef = Database.database().reference()
let array = FUIArray(query: firebaseRef)
```

--------------------------------

### Resolve Sign-In with MFA

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Completes the sign-in process by verifying the provided MFA code.

```APIDOC
## Resolve Sign-In with MFA

### Description
Completes sign-in by verifying the MFA code.

### Method
`resolveSignIn`

### Parameters
- `code` (String) - Required - The MFA code from SMS or TOTP app
- `hintIndex` (Int) - Required - Index of the MFA hint being used
- `verificationId` (String?) - Optional - Verification ID (required for SMS, ignored for TOTP)

### Throws
`AuthServiceError`
```

--------------------------------

### Progressive Image Loading (Swift)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseStorageUI/README.md

Enable progressive downloading and decoding for images loaded from Cloud Storage using StorageReference in Swift. This can improve perceived performance by displaying a low-resolution version of the image while the full image downloads.

```swift
// Use progressive downloading and decoding for images
imageView.sd_setImage(with: reference, placeholderImage: placeholderImage, options: [.progressiveLoad])
```

--------------------------------

### Handle Email Sign-In Link

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Handles the email link flow for both initial sign-in and reauthentication. Routes based on the context of whether `sendEmailSignInLink(email:isReauth:)` was called with `isReauth: true`.

```swift
public func handleSignInLink(url url: URL) async throws
```

--------------------------------

### Initialize FUIArray (Objective-C)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseDatabaseUI/README.md

Initialize an FUIArray to synchronize a Firebase FIRDatabaseReference with an array in Objective-C.

```objective-c
FIRDatabaseReference *firebaseRef = [[FIRDatabase database] reference];
FUIArray *array = [[FUIArray alloc] initWithQuery:firebaseRef];
```

--------------------------------

### Render Authentication Buttons

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Renders all registered authentication provider buttons in a vertical stack. Customize the spacing between buttons using the `spacing` parameter.

```swift
VStack {
  Text("Choose a sign-in method")
  authService.renderButtons(spacing: 12)
}
```

--------------------------------

### Load Image from FIRStorageReference (Objective-C)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseStorageUI/README.md

Use the UIImageView+FirebaseStorage extensions to load an image from a FIRStorageReference. This method utilizes SDWebImage for efficient image loading and caching. A placeholder image can be provided.

```objective-c
// Objective-C

// Reference to an image file in Cloud Storage
FIRStorageReference *reference = ...;

// UIImageView in your ViewController
UIImageView *imageView = ...;

// Load the image using SDWebImage
[imageView sd_setImageWithStorageReference:reference placeholderImage:placeholderImage];
```

--------------------------------

### Sign In with Credential

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Signs in using a provider that conforms to CredentialAuthProviderSwift. Returns either a successful sign-in outcome or indicates that MFA is required.

```APIDOC
## signIn (CredentialAuthProviderSwift)

### Description
Signs in using a provider that conforms to `CredentialAuthProviderSwift`.

### Method Signature
```swift
public func signIn(_ provider: CredentialAuthProviderSwift) async throws -> SignInOutcome
```

### Parameters
- `provider` (CredentialAuthProviderSwift): The authentication provider to use.

### Returns
`SignInOutcome` - either `.signedIn(AuthDataResult?)` or `.mfaRequired(MFARequired)`.

### Throws
`AuthServiceError` or Firebase Auth errors.

### Example
```swift
Task {
  do {
    let outcome = try await authService.signIn(GoogleProviderSwift())
    switch outcome {
    case .signedIn(let result):
      print("Signed in: \(result?.user.email ?? "")")
    case .mfaRequired(let mfaInfo):
      // Handle MFA resolution
      print("MFA required: \(mfaInfo)")
    }
  } catch {
    print("Sign in error: \(error)")
  }
}
```
```

--------------------------------

### Render Authentication Buttons

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Renders all registered authentication provider buttons as a vertical stack.

```APIDOC
## renderButtons

### Description
Renders all registered authentication provider buttons as a vertical stack.

### Method Signature
```swift
public func renderButtons(spacing: CGFloat = 16) -> AnyView
```

### Parameters
- `spacing` (CGFloat): Vertical spacing between buttons (default: 16).

### Returns
An `AnyView` containing all auth buttons.

### Example
```swift
VStack {
  Text("Choose a sign-in method")
  authService.renderButtons(spacing: 12)
}
```
```

--------------------------------

### Resolve Sign-In with MFA

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Completes the sign-in process by verifying the MFA code. Requires the code, hint index, and optionally a verification ID for SMS.

```swift
public func resolveSignIn(
  code: String,
  hintIndex: Int,
  verificationId: String? = nil
) async throws
```

--------------------------------

### AuthConfiguration Struct Definition

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Defines the configurable options for the authentication flow, including UI elements, language codes, and MFA settings.

```swift
public struct AuthConfiguration {
  public init(
    logo: ImageResource? = nil,
    languageCode: String? = nil,
    shouldHideCancelButton: Bool = false,
    interactiveDismissEnabled: Bool = true,
    shouldAutoUpgradeAnonymousUsers: Bool = false,
    customStringsBundle: Bundle? = nil,
    tosUrl: URL? = nil,
    privacyPolicyUrl: URL? = nil,
    emailLinkSignInActionCodeSettings: ActionCodeSettings? = nil,
    verifyEmailActionCodeSettings: ActionCodeSettings? = nil,
    mfaEnabled: Bool = false,
    allowedSecondFactors: Set<SecondFactorType> = [.sms, .totp],
    mfaIssuer: String = "Firebase Auth"
  )
}
```

--------------------------------

### Load Image from StorageReference (Swift)

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseStorageUI/README.md

Use the UIImageView+FirebaseStorage extensions in Swift to load an image from a StorageReference. This method leverages SDWebImage for efficient image loading and caching. A placeholder image can be provided.

```swift
// Swift

// Reference to an image file in Cloud Storage
let reference: StorageReference = ...

// UIImageView in your ViewController
let imageView: UIImageView = ...

// Load the image using SDWebImage
imageView.sd_setImage(with: reference, placeholderImage: placeholderImage)
```

--------------------------------

### CocoaPods Project Configuration

Source: https://github.com/firebase/firebaseui-ios/blob/main/README.md

Ensure these settings are present in your Podfile when using CocoaPods for FirebaseUI.

```ruby
platform :ios, '13.0'
use_frameworks!
```

--------------------------------

### Enable Sign in with Apple using FirebaseUI

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Enables Sign in with Apple authentication. An optional `AppleProviderSwift` can be provided for custom configurations.

```swift
authService
  .withAppleSignIn()
```

--------------------------------

### Enable Sign in with Google using FirebaseUI

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Enables Sign in with Google authentication. An optional `GoogleProviderSwift` can be provided for custom configurations.

```swift
authService
  .withGoogleSignIn()
```

--------------------------------

### AuthService Public Properties

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Provides access to essential configuration and state information for the authentication service, including configuration, Firebase Auth instance, presentation state, current user, authentication state, flow, navigator, and the currently displayed auth view.

```swift
public let configuration: AuthConfiguration
```

```swift
public let auth: Auth
```

```swift
public var isPresented: Bool
```

```swift
public var currentUser: User?
```

```swift
public var authenticationState: AuthenticationState
```

```swift
public var authenticationFlow: AuthenticationFlow
```

```swift
public private(set) var navigator: Navigator
```

```swift
public var authView: AuthView?
```

--------------------------------

### AuthPickerView Usage

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

A pre-built SwiftUI view that provides a complete authentication UI. It automatically handles navigation, error handling, MFA flows, and presents authentication UI as a modal sheet.

```swift
public struct AuthPickerView<Content: View>: View {
  public init(@ViewBuilder content: @escaping () -> Content = { EmptyView() })
}
```

```swift
AuthPickerView {
  // Your app content here
  Text("Welcome!")
}
.environment(authService)
```

--------------------------------

### Sign in with Facebook

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Enables Sign in with Facebook authentication and registers a Facebook button. An optional provider can be supplied.

```APIDOC
## withFacebookSignIn

### Description
Enables Sign in with Facebook authentication and will register a Facebook button that is rendered in AuthPickerView (default Views) or can be rendered in custom Views by calling `AuthService.renderButtons()`.

### Method Signature
```swift
// Available when importing FirebaseFacebookSwiftUI
public func withFacebookSignIn(_ provider: FacebookProviderSwift? = nil) -> AuthService
```

### Parameters
#### Path Parameters
- **provider** (`FacebookProviderSwift?`) - Optional - An optional instance of `FacebookProviderSwift()` for classic login or `FacebookProviderSwift(useClassicLogin: false)` for limited login. If not provided, a default instance with classic login will be created.

### Example
```swift
authService
  .withFacebookSignIn()
```
```

--------------------------------

### Observe Firestore Query with FUIBatchedArray

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseFirestoreUI/README.md

Initialize and observe a Firestore query directly using FUIBatchedArray. This is useful for custom UI implementations that require direct data management and diffing.

```swift
let array = FUIBatchedArray(query: query, delegate: self)
array.observeQuery()
```

--------------------------------

### AuthConfiguration

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

The AuthConfiguration struct allows you to customize the behavior and appearance of the authentication flow, including UI strings, logos, and URLs.

```APIDOC
## AuthConfiguration

### Description
Customizes the behavior and appearance of the authentication flow.

### Initializer
```swift
public init(
  logo: ImageResource? = nil,
  languageCode: String? = nil,
  shouldHideCancelButton: Bool = false,
  interactiveDismissEnabled: Bool = true,
  shouldAutoUpgradeAnonymousUsers: Bool = false,
  customStringsBundle: Bundle? = nil,
  tosUrl: URL? = nil,
  privacyPolicyUrl: URL? = nil,
  emailLinkSignInActionCodeSettings: ActionCodeSettings? = nil,
  verifyEmailActionCodeSettings: ActionCodeSettings? = nil,
  mfaEnabled: Bool = false,
  allowedSecondFactors: Set<SecondFactorType> = [.sms, .totp],
  mfaIssuer: String = "Firebase Auth"
)
```

### Parameters
#### Initializer Parameters
- **logo** (`ImageResource?`) - Optional: Custom logo to display in the authentication UI. Defaults to the Firebase logo.
- **languageCode** (`String?`) - Optional: Language code for localized strings (e.g., "en", "es", "fr"). Defaults to the system language.
- **shouldHideCancelButton** (`Bool`) - Optional: If `true`, hides the cancel button in auth flows. Defaults to `false`.
- **interactiveDismissEnabled** (`Bool`) - Optional: If `false`, prevents users from dismissing auth sheets by swiping down. Defaults to `true`.
- **shouldAutoUpgradeAnonymousUsers** (`Bool`) - Optional: If `true`, automatically links anonymous user accounts with new sign-in credentials. Defaults to `false`.
- **customStringsBundle** (`Bundle?`) - Optional: Custom bundle for string localizations. Allows overriding default strings.
- **tosUrl** (`URL?`) - Optional: URL to your Terms of Service. Displayed when `privacyPolicyUrl` is also set.
- **privacyPolicyUrl** (`URL?`) - Optional: URL to your Privacy Policy. Displayed when `tosUrl` is also set.
- **emailLinkSignInActionCodeSettings** (`ActionCodeSettings?`) - Optional: Configuration for email link (passwordless) sign-in. Required for email link authentication.
- **verifyEmailActionCodeSettings** (`ActionCodeSettings?`) - Optional: Configuration for email verification.
- **mfaEnabled** (`Bool`) - Optional: Enables Multi-Factor Authentication support. Defaults to `false`.
- **allowedSecondFactors** (`Set<SecondFactorType>`) - Optional: Set of allowed MFA factor types. Defaults to `[.sms, .totp]`.
- **mfaIssuer** (`String`) - Optional: The issuer name displayed in TOTP authenticator apps. Defaults to `"Firebase Auth"`.

### Notes
- Both `tosUrl` and `privacyPolicyUrl` must be set for the links to appear in the UI.
- `emailLinkSignInActionCodeSettings` requires `handleCodeInApp = true`, a valid `url`, and an iOS bundle ID configured via `setIOSBundleID()`.
```

--------------------------------

### AuthService

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

The main service class that manages authentication state and operations.

```APIDOC
## AuthService

### Description
Manages authentication state and operations.

### Initialization
```swift
public init(
  configuration: AuthConfiguration = AuthConfiguration(),
  auth: Auth = Auth.auth()
)
```

#### Parameters
- **configuration** (`AuthConfiguration`) - Configuration for auth behavior. Defaults to `AuthConfiguration()`.
- **auth** (`Auth`) - Firebase Auth instance to use. Defaults to `Auth.auth()`.
```

--------------------------------

### Email Authentication

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Enables email authentication and renders email sign-in within the AuthPickerView. A custom callback can be provided for tap events.

```APIDOC
## withEmailSignIn

### Description
Enables email authentication and will render email sign-in directly within the AuthPickerView (default Views), email link sign-in is rendered as a button. When calling `AuthService.renderButtons()`, email link sign-in button is rendered. `onTap` custom callback (i.e where to navigate when tapped) allows user to control what happens when tapped. Default behavior in AuthPickerView is to push the user to email link sign-in default View.

### Method Signature
```swift
public func withEmailSignIn(onTap: @escaping () -> Void = {}) -> AuthService
```

### Parameters
#### Closure Parameter
- **onTap** (`@escaping () -> Void`) - Required/Optional - A callback that will be executed when the email button is tapped.

### Example
```swift
authService
  .withEmailSignIn()

// or

authService
  .withEmailSignIn() {
    // navigate to email sign-in screen logic
  }
```
```

--------------------------------

### Enable Email Sign-In with FirebaseUI

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Enables email authentication. Use the `onTap` callback to customize navigation when the email button is tapped.

```swift
authService
  .withEmailSignIn()
```

```swift
authService
  .withEmailSignIn() {
    // navigate to email sign-in screen logic
  }
```

--------------------------------

### Generic OAuth Providers

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Enables authentication with generic OAuth/OIDC providers. This method registers an OAuth button that can be rendered in AuthPickerView or custom Views by calling AuthService.renderButtons().

```APIDOC
## withOAuthSignIn

### Description
Enables authentication with generic OAuth/OIDC providers and will register an OAuth button that is rendered in AuthPickerView (default Views) or can be rendered in custom Views by calling `AuthService.renderButtons()`.

### Method Signature
```swift
public func withOAuthSignIn(_ provider: OAuthProviderSwift) -> AuthService
```

### Parameters
- `provider` (OAuthProviderSwift): An instance of OAuthProviderSwift representing the OAuth provider (e.g., GitHub, Microsoft, Yahoo, or a custom provider).

### Built-in Providers
- `OAuthProviderSwift.github()`
- `OAuthProviderSwift.microsoft()`
- `OAuthProviderSwift.yahoo()`

### Custom Provider
```swift
OAuthProviderSwift(
  providerId: String,
  displayName: String,
  buttonIcon: Image,
  buttonBackgroundColor: Color,
  buttonForegroundColor: Color
)
```

### Example
```swift
authService
  .withOAuthSignIn(OAuthProviderSwift.github())
  .withOAuthSignIn(OAuthProviderSwift.microsoft())
  .withOAuthSignIn(
    OAuthProviderSwift(
      providerId: "oidc.custom-provider",
      displayName: "Sign in with Custom",
      buttonIcon: Image("custom-logo"),
      buttonBackgroundColor: .blue,
      buttonForegroundColor: .white
    )
  )
```
```

--------------------------------

### SignInOutcome Enum

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Defines the possible outcomes of a sign-in attempt, either a successful sign-in with optional user data or a requirement for Multi-Factor Authentication.

```swift
public enum SignInOutcome {
  case mfaRequired(MFARequired)
  case signedIn(AuthDataResult?)
}
```

--------------------------------

### Link User Accounts

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Links a new authentication method to the current user's account. Requires a valid AuthCredential object.

```swift
try await authService.linkAccounts(credentials: someAuthCredential)
```

--------------------------------

### Link Accounts

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Links a new authentication method to the current user's account.

```APIDOC
## linkAccounts

### Description
Links a new authentication method to the current user's account.

### Method Signature
```swift
public func linkAccounts(credentials credentials: AuthCredential) async throws
```

### Parameters
- `credentials` (AuthCredential): The credential to link.

### Throws
`AuthServiceError` or Firebase Auth errors.
```

--------------------------------

### Reauthenticate Email/Password for Password Update

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Catch the .emailReauthenticationRequired error, prompt for the user's password, create a credential, and reauthenticate before retrying the password update.

```swift
do {
  try await authService.updatePassword(to: newPassword)
} catch let error as AuthServiceError {
  if case .emailReauthenticationRequired(let context) = error {
    // Show your password prompt UI
    let password = await promptUserForPassword()
    let credential = EmailAuthProvider.credential(
      withEmail: context.email,
      password: password
    )
    try await authService.reauthenticate(with: credential)
    try await authService.updatePassword(to: newPassword) // Retry
  }
}
```

--------------------------------

### Sign in with Twitter

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Enables Sign in with Twitter authentication and registers a Twitter button. An optional provider can be supplied.

```APIDOC
## withTwitterSignIn

### Description
Enables Sign in with Twitter authentication and will register a Twitter button that is rendered in AuthPickerView (default Views) or can be rendered in custom Views by calling `AuthService.renderButtons()`.

### Method Signature
```swift
// Available when importing FirebaseTwitterSwiftUI
public func withTwitterSignIn(_ provider: TwitterProviderSwift? = nil) -> AuthService
```

### Parameters
#### Path Parameters
- **provider** (`TwitterProviderSwift?`) - Optional - An optional instance of `TwitterProviderSwift`. If not provided, a default instance will be created.

### Example
```swift
authService
  .withTwitterSignIn()
```
```

--------------------------------

### Enable Sign in with Facebook using FirebaseUI

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Enables Sign in with Facebook authentication. An optional `FacebookProviderSwift` can be provided for classic or limited login.

```swift
authService
  .withFacebookSignIn()
```

--------------------------------

### Send Email Sign-In Link

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Sends a passwordless sign-in link to the specified email address. This can also be used for reauthentication.

```APIDOC
## sendEmailSignInLink

### Description
Sends a sign-in link to the specified email address. Can also be used for reauthentication.

### Method Signature
```swift
public func sendEmailSignInLink(email: String, isReauth: Bool = false) async throws
```

### Parameters
- `email` (String): Email address to send the link to.
- `isReauth` (Bool): Whether this is for reauthentication (default: `false`).

### Throws
`AuthServiceError` or Firebase Auth errors.

### Requirements
`emailLinkSignInActionCodeSettings` must be configured in `AuthConfiguration`.

### Note
When `isReauth` is `true`, the method stores the email for reauthentication flow. The same `handleSignInLink(url:)` method handles both sign-in and reauthentication automatically.
```

--------------------------------

### Verify Phone Number for Authentication

Source: https://github.com/firebase/firebaseui-ios/blob/main/FirebaseSwiftUI/README.md

Sends a verification code to a specified phone number. Requires the phone number in E.164 format.

```swift
public func verifyPhoneNumber(phoneNumber: String) async throws -> String
```