使用 Google Firebase 的 iOS Swift Facebook 身份验证 - 如何获取额外权限？

Question

我使用最新版本的 Facebook SDK 4.15 和 Google Firebase 来验证用户。我正在关注此处的文档:https://firebase.google.com/docs/auth/ios/facebook-login

这对我有用。

但是我想从 Facebook 用户那里获得额外的权限，比如电子邮件。我已经像这样修改了代码:

@IBOutlet var facebookButton : FBSDKLoginButton!


override func viewDidLoad() {
/...
  facebookButton.readPermissions = ["email","public_profile"]
...
}

有了这个，当我通过 Facebook 授权我的应用程序时，我得到了 Facebook 确认对话框，要求电子邮件许可。这样就可以了。

但是在我的回调中，用户的电子邮件地址始终为零:

func loginButton(loginButton: FBSDKLoginButton!, didCompleteWithResult result: FBSDKLoginManagerLoginResult!, error: NSError?) {
  if let error = error {
    print(error.localizedDescription)
    return
  }

  let credential = FIRFacebookAuthProvider.credentialWithAccessToken(FBSDKAccessToken.currentAccessToken().tokenString)
  FIRAuth.auth()?.signInWithCredential(credential) { (user, error) in
    // ...  
    if let error = error {
      print(error.localizedDescription)
      return
   }

    print("user.uid \(user!.uid)")
    print("user.photoURL \(user!.photoURL)")
    print("user.providerID \(user!.providerID)")
    print("user.email \(user!.email)")
    print("user.displayName \(user!.displayName)")

如何在使用 Google Firebase 身份验证时通过 Facebook 登录获取电子邮件等额外权限？

Answer 1

使用第三方身份验证时，您会取回身份验证 token ，然后使用该 token 让用户登录您的应用。有了这个 token ，Firebase Auth 就可以提取用户的电子邮件地址。但是对于您的情况，如果您希望在 FB 登录后获取用户的电子邮件地址，则需要使用 Facebook 的 Graph API。您只需创建一个包含您要求的信息的 GraphRequest，如下所示。

swift 2

struct FacebookPermission
{
    static let ID: String = "id"
    static let NAME: String = "name"
    static let EMAIL: String = "email"
    static let PROFILE_PIC: String = "picture"
    static let LAST_NAME: String = "last_name"
    static let FIRST_NAME: String = "first_name"
    static let USER_FRIENDS: String = "user_friends"
    static let PUBLIC_PROFILE: String = "public_profile"
}

func getFacebookData()
{
    let graphRequest: FBSDKGraphRequest = FBSDKGraphRequest(graphPath: "me", parameters: ["fields" : "\(FacebookPermission.NAME), \(FacebookPermission.FIRST_NAME), \(FacebookPermission.LAST_NAME), \(FacebookPermission.EMAIL), \(FacebookPermission.PROFILE_PIC).type(large)"])

    graphRequest.startWithCompletionHandler { (connection: FBSDKGraphRequestConnection!, result:AnyObject!, error: NSError!) in

        if error == nil
        {
            if let userName = result.valueForKey(FacebookPermission.NAME) as? String
            {
                self.currentUser.userName = userName
            }

            if let firstName = result.valueForKey(FacebookPermission.FIRST_NAME) as? String
            {
                self.currentUser.firstName = firstName
            }

            if let lastName = result.valueForKey(FacebookPermission.LAST_NAME) as? String
            {
                self.currentUser.lastName = lastName
            }

            if let email = result.valueForKey(FacebookPermission.EMAIL) as? String
            {
                self.currentUser.email = email
            }

            if let profilePic = result.valueForKey(FacebookPermission.PROFILE_PIC)
            {
                let facebookImageURL = profilePic.valueForKey("data")?.valueForKey("url") as? String

                if let unwrappedURL = facebookImageURL
                {
                    let imageData: NSData = NSData(contentsOfURL: NSURL(string: unwrappedURL)!)!
                    self.currentUser.profileImage = UIImage(data: imageData)!
                }
            }
        }
        else
        {
            print("Facebook Graph Request Error")
        }
    }
}

swift 3

func getFacebookData()
{
    let graphRequest: FBSDKGraphRequest = FBSDKGraphRequest(graphPath: "me", parameters: ["fields" : "\(FacebookPermission.NAME), \(FacebookPermission.FIRST_NAME), \(FacebookPermission.LAST_NAME), \(FacebookPermission.EMAIL), \(FacebookPermission.PROFILE_PIC).type(large)"])

    graphRequest.start { (connection: FBSDKGraphRequestConnection?, result: Any?, error: Error?) in

        if error == nil
        {
            if let facebookData = result as? NSDictionary
            {
                if let userName = facebookData.value(forKey: FacebookPermission.NAME) as? String
                {
                    self.currentUser.userName = userName
                }

                if let firstName = facebookData.value(forKey: FacebookPermission.FIRST_NAME) as? String
                {
                    self.currentUser.firstName = firstName
                }

                if let lastName = facebookData.value(forKey: FacebookPermission.LAST_NAME) as? String
                {
                    self.currentUser.lastName = lastName
                }

                if let email = facebookData.value(forKey: FacebookPermission.EMAIL) as? String
                {
                    self.currentUser.email = email
                }

                if let profilePic = facebookData.value(forKey: FacebookPermission.PROFILE_PIC)
                {
                    let facebookImageURL = ((profilePic as AnyObject).value(forKey: "data") as AnyObject).value(forKey: "url") as? String

                    if let unwrappedURL = facebookImageURL
                    {
                        let imageData: Data = try! Data(contentsOf: URL(string: unwrappedURL)!)
                        self.currentUser.profileImage = UIImage(data: imageData)!
                    }
                }
            }
        }
        else
        {
            print("Facebook Graph Request Error")
        }
    }
}

获取他们的信息后，您可以继续将其存储到您的 Firebase 数据库中。

Here's有关 Facebook 权限的更多信息。伙计，干杯!