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將多個身份驗證提供者鏈接到 Apple 平台上的帳戶

透過集合功能整理內容 你可以依據偏好儲存及分類內容。

您可以通過將身份驗證提供程序憑據鏈接到現有用戶帳戶來允許用戶使用多個身份驗證提供程序登錄您的應用程序。用戶可以通過相同的 Firebase 用戶 ID 來識別,無論他們用於登錄的身份驗證提供商是什麼。例如,使用密碼登錄的用戶可以關聯一個 Google 帳戶,並在將來使用任何一種方法登錄。或者,匿名用戶可以鏈接 Facebook 帳戶,然後再登錄 Facebook 以繼續使用您的應用程序。

在你開始之前

為您的應用添加對兩個或更多身份驗證提供程序(可能包括匿名身份驗證)的支持。

要將身份驗證提供者憑據鏈接到現有用戶帳戶:

  1. 使用任何身份驗證提供程序或方法登錄用戶。
  2. 完成新身份驗證提供程序的登錄流程,直至(但不包括)調用FIRAuth.signInWith方法之一。例如,獲取用戶的 Google ID 令牌、Facebook 訪問令牌或電子郵件和密碼。
  3. 為新的身份驗證提供程序獲取FIRAuthCredential

    谷歌登錄
    迅速
    guard
      let authentication = user?.authentication,
      let idToken = authentication.idToken
    else {
      return
    }
    
    let credential = GoogleAuthProvider.credential(withIDToken: idToken,
                                                   accessToken: authentication.accessToken)
    
    Objective-C
    GIDAuthentication *authentication = user.authentication;
    FIRAuthCredential *credential =
    [FIRGoogleAuthProvider credentialWithIDToken:authentication.idToken
                                     accessToken:authentication.accessToken];
    
    Facebook登入
    迅速
    let credential = FacebookAuthProvider
      .credential(withAccessToken: AccessToken.current!.tokenString)
    
    Objective-C
    FIRAuthCredential *credential = [FIRFacebookAuthProvider
        credentialWithAccessToken:[FBSDKAccessToken currentAccessToken].tokenString];
    
    電子郵件密碼登錄
    迅速
    let credential = EmailAuthProvider.credential(withEmail: email, password: password)
    
    Objective-C
    FIRAuthCredential *credential =
        [FIREmailAuthProvider credentialWithEmail:email
                                                 password:password];
    
  4. FIRAuthCredential對像傳遞給登錄用戶的linkWithCredential:completion:方法:

    迅速
        user.link(with: credential) { authResult, error in
      // ...
    }
    }
    
    Objective-C
        [[FIRAuth auth].currentUser linkWithCredential:credential
        completion:^(FIRAuthDataResult *result, NSError *_Nullable error) {
      // ...
    }];
    

    如果憑據已鏈接到另一個用戶帳戶,則對linkWithCredential:completion:的調用將失敗。在這種情況下,您必鬚根據應用程序的需要處理合併帳戶和關聯數據:

    迅速

    let prevUser = Auth.auth().currentUser
    Auth.auth().signIn(with: credential) { authResult, error in
        if let error = error {
          let authError = error as NSError
          if isMFAEnabled, authError.code == AuthErrorCode.secondFactorRequired.rawValue {
            // The user is a multi-factor user. Second factor challenge is required.
            let resolver = authError
              .userInfo[AuthErrorUserInfoMultiFactorResolverKey] as! MultiFactorResolver
            var displayNameString = ""
            for tmpFactorInfo in resolver.hints {
              displayNameString += tmpFactorInfo.displayName ?? ""
              displayNameString += " "
            }
            self.showTextInputPrompt(
              withMessage: "Select factor to sign in\n\(displayNameString)",
              completionBlock: { userPressedOK, displayName in
                var selectedHint: PhoneMultiFactorInfo?
                for tmpFactorInfo in resolver.hints {
                  if displayName == tmpFactorInfo.displayName {
                    selectedHint = tmpFactorInfo as? PhoneMultiFactorInfo
                  }
                }
                PhoneAuthProvider.provider()
                  .verifyPhoneNumber(with: selectedHint!, uiDelegate: nil,
                                     multiFactorSession: resolver
                                       .session) { verificationID, error in
                    if error != nil {
                      print(
                        "Multi factor start sign in failed. Error: \(error.debugDescription)"
                      )
                    } else {
                      self.showTextInputPrompt(
                        withMessage: "Verification code for \(selectedHint?.displayName ?? "")",
                        completionBlock: { userPressedOK, verificationCode in
                          let credential: PhoneAuthCredential? = PhoneAuthProvider.provider()
                            .credential(withVerificationID: verificationID!,
                                        verificationCode: verificationCode!)
                          let assertion: MultiFactorAssertion? = PhoneMultiFactorGenerator
                            .assertion(with: credential!)
                          resolver.resolveSignIn(with: assertion!) { authResult, error in
                            if error != nil {
                              print(
                                "Multi factor finanlize sign in failed. Error: \(error.debugDescription)"
                              )
                            } else {
                              self.navigationController?.popViewController(animated: true)
                            }
                          }
                        }
                      )
                    }
                  }
              }
            )
          } else {
            self.showMessagePrompt(error.localizedDescription)
            return
          }
          // ...
          return
        }
        // User is signed in
        // ...
    }
                // Merge prevUser and currentUser accounts and data
                // ...
            }
    

    Objective-C

    FIRUser *prevUser = [FIRAuth auth].currentUser;
    [[FIRAuth auth] signInWithCredential:credential
                              completion:^(FIRAuthDataResult * _Nullable authResult,
                                           NSError * _Nullable error) {
        if (isMFAEnabled && error && error.code == FIRAuthErrorCodeSecondFactorRequired) {
          FIRMultiFactorResolver *resolver = error.userInfo[FIRAuthErrorUserInfoMultiFactorResolverKey];
          NSMutableString *displayNameString = [NSMutableString string];
          for (FIRMultiFactorInfo *tmpFactorInfo in resolver.hints) {
            [displayNameString appendString:tmpFactorInfo.displayName];
            [displayNameString appendString:@" "];
          }
          [self showTextInputPromptWithMessage:[NSString stringWithFormat:@"Select factor to sign in\n%@", displayNameString]
                               completionBlock:^(BOOL userPressedOK, NSString *_Nullable displayName) {
           FIRPhoneMultiFactorInfo* selectedHint;
           for (FIRMultiFactorInfo *tmpFactorInfo in resolver.hints) {
             if ([displayName isEqualToString:tmpFactorInfo.displayName]) {
               selectedHint = (FIRPhoneMultiFactorInfo *)tmpFactorInfo;
             }
           }
           [FIRPhoneAuthProvider.provider
            verifyPhoneNumberWithMultiFactorInfo:selectedHint
            UIDelegate:nil
            multiFactorSession:resolver.session
            completion:^(NSString * _Nullable verificationID, NSError * _Nullable error) {
              if (error) {
                [self showMessagePrompt:error.localizedDescription];
              } else {
                [self showTextInputPromptWithMessage:[NSString stringWithFormat:@"Verification code for %@", selectedHint.displayName]
                                     completionBlock:^(BOOL userPressedOK, NSString *_Nullable verificationCode) {
                 FIRPhoneAuthCredential *credential =
                     [[FIRPhoneAuthProvider provider] credentialWithVerificationID:verificationID
                                                                  verificationCode:verificationCode];
                 FIRMultiFactorAssertion *assertion = [FIRPhoneMultiFactorGenerator assertionWithCredential:credential];
                 [resolver resolveSignInWithAssertion:assertion completion:^(FIRAuthDataResult * _Nullable authResult, NSError * _Nullable error) {
                   if (error) {
                     [self showMessagePrompt:error.localizedDescription];
                   } else {
                     NSLog(@"Multi factor finanlize sign in succeeded.");
                   }
                 }];
               }];
              }
            }];
         }];
        }
      else if (error) {
        // ...
        return;
      }
      // User successfully signed in. Get user data from the FIRUser object
      if (authResult == nil) { return; }
      FIRUser *user = authResult.user;
      // ...
    }];
                                        // Merge prevUser and currentUser accounts and data
                                        // ...
                                    }];
    

如果對linkWithCredential:completion:的調用成功,則用戶現在可以使用任何鏈接的身份驗證提供程序登錄並訪問相同的 Firebase 數據。

您可以取消身份驗證提供程序與帳戶的鏈接,以便用戶無法再使用該提供程序登錄。

要將身份驗證提供程序與用戶帳戶取消鏈接,請將提供程序 ID 傳遞給unlinkFromProvider:completion:方法。您可以從providerData屬性獲取鏈接到用戶的身份驗證提供程序的提供程序 ID。

迅速

Auth.auth().currentUser?.unlink(fromProvider: providerID!) { user, error in
  // ...
}

Objective-C

[[FIRAuth auth].currentUser unlinkFromProvider:providerID
                                    completion:^(FIRUser *_Nullable user, NSError *_Nullable error) {
  // ...
}];