您可以透過將身分驗證提供者憑證連結到現有使用者帳戶,允許使用者使用多個驗證提供者登入您的應用程式。無論使用者用於登入的驗證提供者為何,都可以透過相同的 Firebase 使用者 ID 來識別使用者。例如,使用密碼登入的使用者可以關聯 Google 帳戶,並在將來使用任一方法登入。或者,匿名用戶可以連結 Facebook 帳戶,然後使用 Facebook 登入以繼續使用您的應用程式。
在你開始之前
在您的應用程式中新增對兩個或多個身份驗證提供者(可能包括匿名身份驗證)的支援。
將身份驗證提供者憑證連結到使用者帳戶
若要將身分驗證提供者憑證連結到現有使用者帳戶:
- 使用任何身份驗證提供者或方法登入使用者。
- 完成新驗證提供者的登入流程,直到(但不包含)呼叫
FIRAuth.signInWith
方法之一。例如,取得使用者的 Google ID 令牌、Facebook 存取權令牌或電子郵件和密碼。 取得新身分驗證提供者的
FIRAuthCredential
:Google登入
迅速
guard let authentication = user?.authentication, let idToken = authentication.idToken else { return } let credential = GoogleAuthProvider.credential(withIDToken: idToken, accessToken: authentication.accessToken)
Objective-C
FIRAuthCredential *credential = [FIRGoogleAuthProvider credentialWithIDToken:result.user.idToken.tokenString accessToken:result.user.accessToken.tokenString];
Facebook登入
迅速
let credential = FacebookAuthProvider .credential(withAccessToken: AccessToken.current!.tokenString)
Objective-C
FIRAuthCredential *credential = [FIRFacebookAuthProvider credentialWithAccessToken:[FBSDKAccessToken currentAccessToken].tokenString];
郵件信箱密碼登入
迅速
let credential = EmailAuthProvider.credential(withEmail: email, password: password)
Objective-C
FIRAuthCredential *credential = [FIREmailAuthProvider credentialWithEmail:email password:password];
將
FIRAuthCredential
物件傳遞給登入使用者的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) { // ... }];
如果憑證已連結到另一個使用者帳戶,則對
linkWithCredential:completion:
呼叫將會失敗。在這種情況下,您必須根據您的應用程式處理帳戶和關聯資料的合併: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:
的呼叫成功,使用者現在可以使用任何連結的身份驗證提供者登入並存取相同的 Firebase 資料。
取消身份驗證提供者與用戶帳戶的鏈接
您可以取消身份驗證提供者與帳戶的鏈接,以便用戶無法再使用該提供者登入。
若要取消身份驗證提供者與使用者帳戶的鏈接,請將提供者 ID 傳遞給unlink
方法。您可以從providerData
屬性取得連結到使用者的驗證提供者的提供者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) { // ... }];