LoginManager

Use LoginManager to programmatically log users in and out of your iOS app with Facebook.

LoginManager is the primary class for triggering the Facebook Login flow. It handles browser or native app switching, the OAuth callback, token storage, and logout. You interact with it directly when you want full control over when and how the login UI appears.

Instantiate LoginManager

let loginManager = LoginManager()

You can also set the default audience at init time if you intend to request publish permissions:

let loginManager = LoginManager(defaultAudience: .friends)

The defaultAudience property controls the initial audience for posts made through your app. The available values are:

Value	Description
.friends	The user’s friends can see posts (default)
.onlyMe	Only the user can see posts
.everyone	All Facebook users can see posts

Check for a cached token first

Before calling logIn, check whether the user is already authenticated. Doing this in viewDidLoad avoids an unnecessary login prompt:

override func viewDidLoad() {
    super.viewDidLoad()

    if let token = AccessToken.current, !token.isExpired {
        // Already logged in — update your UI
        showLoggedInState(token: token)
    }
}

Log in with a configuration

Build a LoginConfiguration with the permissions you need, then call logIn(viewController:configuration:completion:):

func logInWithFacebook() {
    guard let config = LoginConfiguration(
        permissions: [.publicProfile, .email],
        tracking: .enabled
    ) else { return }

    loginManager.logIn(viewController: self, configuration: config) { result in
        self.handleLoginResult(result)
    }
}

You can only perform one login call at a time. Calling logIn again before the previous completion handler fires will result in an error.

Pass nil for viewController and the SDK will determine the topmost view controller automatically.

Handle the LoginResult

The completion block receives a LoginResult, which is a Swift enum with three cases:

func handleLoginResult(_ result: LoginResult) {
    switch result {
    case let .success(granted, declined, token):
        print("Granted permissions: \(granted.map(\.name))")
        if !declined.isEmpty {
            print("Declined permissions: \(declined.map(\.name))")
        }
        if let token = token {
            print("Access token: \(token.tokenString)")
        }

    case .cancelled:
        print("User cancelled the login")

    case let .failed(error):
        print("Login failed with error: \(error)")
    }
}

The granted and declined sets reflect only the permissions affected in this login request, not the full historical set. Check AccessToken.current?.permissions for the complete granted set.

Log out

Call logOut() to clear the cached AccessToken, AuthenticationToken, and Profile:

func logOut() {
    loginManager.logOut()
    // AccessToken.current is now nil
    showLoggedOutState()
}

This is a client-side logout only. It does not revoke the token on Facebook’s servers or log the user out of the Facebook app.

Reauthorize data access

Facebook periodically expires data access for inactive users. When AccessToken.isDataAccessExpired is true, call reauthorizeDataAccess(from:handler:) to restore it without asking for new permissions:

func reauthorizeIfNeeded() {
    guard let token = AccessToken.current, token.isDataAccessExpired else { return }

    loginManager.reauthorizeDataAccess(from: self) { result, error in
        if let error = error {
            print("Reauthorization failed: \(error)")
        } else {
            print("Data access restored")
        }
    }
}

reauthorizeDataAccess requires an existing AccessToken.current. Calling it without one will return an error with code LoginError.missingAccessToken.

Request additional permissions

If a feature in your app needs permissions you did not request at login, call logIn again with the new permissions. The SDK shows the Facebook dialog only for the permissions not yet granted:

func requestEmailPermission() {
    guard let config = LoginConfiguration(
        permissions: [.email],
        tracking: .enabled
    ) else { return }

    loginManager.logIn(viewController: self, configuration: config) { result in
        switch result {
        case let .success(granted, declined, _):
            if declined.contains(.email) {
                // User declined email — explain why it's needed
            }
        case .cancelled, .failed:
            break
        }
    }
}

Do not request all permissions upfront. Request each permission at the moment your app needs it, so users understand why the data is required.