프로그램에 정기적으로 실행되는 업데이트 루프(예: 초당 30회 또는 60회)가 있는 경우 다음과 같이 Auth::SignInWithCustomTokenLastResult를 사용해 업데이트 시마다 한 번씩 결과를 확인할 수 있습니다.
firebase::Future<firebase::auth::AuthResult>result=auth->SignInWithCustomTokenLastResult();if(result.status()==firebase::kFutureStatusComplete){if(result.error()==firebase::auth::kAuthErrorNone){firebase::auth::AuthResultauth_result=*result.result();printf("Sign in succeeded for `%s`\n",auth_result.user.display_name().c_str());}else{printf("Sign in failed with error '%s'\n",result.error_message());}}
사용자가 처음으로 로그인하면 신규 사용자 계정이 생성되고 사용자가 로그인할 때 사용한 사용자 인증 정보(사용자 이름과 비밀번호, 전화번호 또는 인증 제공업체 정보)에 연결됩니다. 이 신규 계정은 Firebase 프로젝트에 저장되며 사용자의 로그인 방법과 무관하게 프로젝트 내의 모든 앱에서 사용자를 식별하는 데 사용할 수 있습니다.
firebase::auth::Useruser=auth->current_user();if(user.is_valid()){std::stringname=user.display_name();std::stringemail=user.email();std::stringphoto_url=user.photo_url();// The user's ID, unique to the Firebase project.// Do NOT use this value to authenticate with your backend server,// if you have one. Use firebase::auth::User::Token() instead.std::stringuid=user.uid();}
Firebase Realtime Database와 Cloud Storage보안 규칙의 auth 변수에서 로그인한 사용자의 고유 사용자 ID를 가져온 후 이 ID를 통해 사용자가 액세스할 수 있는 데이터를 관리할 수 있습니다.
[[["이해하기 쉬움","easyToUnderstand","thumb-up"],["문제가 해결됨","solvedMyProblem","thumb-up"],["기타","otherUp","thumb-up"]],[["필요한 정보가 없음","missingTheInformationINeed","thumb-down"],["너무 복잡함/단계 수가 너무 많음","tooComplicatedTooManySteps","thumb-down"],["오래됨","outOfDate","thumb-down"],["번역 문제","translationIssue","thumb-down"],["샘플/코드 문제","samplesCodeIssue","thumb-down"],["기타","otherDown","thumb-down"]],["최종 업데이트: 2025-09-04(UTC)"],[],[],null,["You can integrate Firebase Authentication with a custom authentication system by\nmodifying your authentication server to produce custom signed tokens when a user\nsuccessfully signs in. Your app receives this token and uses it to authenticate\nwith Firebase.\n\nBefore you begin\n\n1. [Add Firebase to your C++\n project](/docs/cpp/setup#note_select_platform).\n2. Get your project's server keys:\n 1. Go to the [Service Accounts](https://console.firebase.google.com/project/_/settings/serviceaccounts/adminsdk) page in your project's settings.\n 2. Click *Generate New Private Key* at the bottom of the *Firebase Admin SDK* section of the *Service Accounts* page.\n 3. The new service account's public/private key pair is automatically saved on your computer. Copy this file to your authentication server.\n\nAuthenticate with Firebase The `Auth` class is the gateway for all API calls.\n\n1. Add the Auth and App header files: \n\n ```c++\n #include \"firebase/app.h\"\n #include \"firebase/auth.h\"\n ```\n2. In your initialization code, create a [`firebase::App`](/docs/reference/cpp/class/firebase/app) class. \n\n ```c++\n #if defined(__ANDROID__)\n firebase::App* app =\n firebase::App::Create(firebase::AppOptions(), my_jni_env, my_activity);\n #else\n firebase::App* app = firebase::App::Create(firebase::AppOptions());\n #endif // defined(__ANDROID__)\n ```\n3. Acquire the `firebase::auth::Auth` class for your `firebase::App`. There is a one-to-one mapping between `App` and `Auth`. \n\n ```c++\n firebase::auth::Auth* auth = firebase::auth::Auth::GetAuth(app);\n ```\n\nCall `Auth::SignInWithCustomToken` with the token from your authentication server.\n\n1. When users sign in to your app, send their sign-in credentials (for example, their username and password) to your authentication server. Your server checks the credentials and returns a [custom token](/docs/auth/admin/create-custom-tokens) if they are valid.\n2. After you receive the custom token from your authentication server, pass it to `Auth::SignInWithCustomToken` to sign in the user: \n\n ```c++\n firebase::Future\u003cfirebase::auth::AuthResult\u003e result =\n auth-\u003eSignInWithCustomToken(custom_token);\n ```\n3. If your program has an update loop that runs regularly (say at 30 or 60 times per second), you can check the results once per update with `Auth::SignInWithCustomTokenLastResult`: \n\n ```c++\n firebase::Future\u003cfirebase::auth::AuthResult\u003e result =\n auth-\u003eSignInWithCustomTokenLastResult();\n if (result.status() == firebase::kFutureStatusComplete) {\n if (result.error() == firebase::auth::kAuthErrorNone) {\n firebase::auth::AuthResult auth_result = *result.result();\n printf(\"Sign in succeeded for `%s`\\n\",\n auth_result.user.display_name().c_str());\n } else {\n printf(\"Sign in failed with error '%s'\\n\", result.error_message());\n }\n }\n ```\n Or, if your program is event driven, you may prefer to [register a callback on the\n Future](#register_callback_on_future).\n\nNext steps\n\nAfter a user signs in for the first time, a new user account is created and\nlinked to the credentials---that is, the user name and password, phone\nnumber, or auth provider information---the user signed in with. This new\naccount is stored as part of your Firebase project, and can be used to identify\na user across every app in your project, regardless of how the user signs in.\n\n- In your apps, you can get the user's basic profile information from the\n [`firebase::auth::User`](/docs/reference/cpp/class/firebase/auth/user) object:\n\n ```c++\n firebase::auth::User user = auth-\u003ecurrent_user();\n if (user.is_valid()) {\n std::string name = user.display_name();\n std::string email = user.email();\n std::string photo_url = user.photo_url();\n // The user's ID, unique to the Firebase project.\n // Do NOT use this value to authenticate with your backend server,\n // if you have one. Use firebase::auth::User::Token() instead.\n std::string uid = user.uid();\n }\n ```\n- In your Firebase Realtime Database and Cloud Storage\n [Security Rules](/docs/database/security/user-security), you can\n get the signed-in user's unique user ID from the `auth` variable,\n and use it to control what data a user can access.\n\nYou can allow users to sign in to your app using multiple authentication\nproviders by [linking auth provider credentials to an\nexisting user account.](/docs/auth/cpp/account-linking)\n\nTo sign out a user, call [`SignOut()`](/docs/reference/cpp/class/firebase/auth/auth#signout): \n\n```c++\nauth-\u003eSignOut();\n```"]]
