firebase.auth().languageCode = 'pt';
// To apply the default browser preference instead of explicitly setting it.
// firebase.auth().useDeviceLanguage();
使用 Google 提供方对象进行 Firebase 身份验证：您可以通过打开弹出式窗口或重定向至登录页面，提示用户使用自己的 Google 帐号登录。在移动设备上最好使用重定向方法。
要使用弹出式窗口登录，请调用 signInWithPopup：
firebase.auth().signInWithPopup(provider).then(function(result) {
// This gives you a Google Access Token. You can use it to access the Google API.
var token = result.credential.accessToken;
// The signed-in user info.
var user = result.user;
// ...
}).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
// The email of the user's account used.
var email = error.email;
// The firebase.auth.AuthCredential type that was used.
var credential = error.credential;
// ...
});
此外请注意，您可以检索 Google 提供方的 OAuth 令牌，使用该令牌可通过 Google API 提取额外数据。
然后，您还可以在页面加载时通过调用 getRedirectResult 来检索 Google 提供方的 OAuth 令牌：
firebase.auth().getRedirectResult().then(function(result) {
if (result.credential) {
// This gives you a Google Access Token. You can use it to access the Google API.
var token = result.credential.accessToken;
// ...
}
// The signed-in user info.
var user = result.user;
}).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
// The email of the user's account used.
var email = error.email;
// The firebase.auth.AuthCredential type that was used.
var credential = error.credential;
// ...
});
// Step 1.
// User tries to sign in to Google.
auth.signInWithPopup(new firebase.auth.GoogleAuthProvider()).catch(function(error) {
// An error happened.
if (error.code === 'auth/account-exists-with-different-credential') {
// Step 2.
// User's email already exists.
// The pending Google credential.
var pendingCred = error.credential;
// The provider account's email address.
var email = error.email;
// Get sign-in methods for this email.
auth.fetchSignInMethodsForEmail(email).then(function(methods) {
// Step 3.
// If the user has several sign-in methods,
// the first method in the list will be the "recommended" method to use.
if (methods[0] === 'password') {
// Asks the user their password.
// In real scenario, you should handle this asynchronously.
var password = promptUserForPassword(); // TODO: implement promptUserForPassword.
auth.signInWithEmailAndPassword(email, password).then(function(user) {
// Step 4a.
return user.linkWithCredential(pendingCred);
}).then(function() {
// Google account successfully linked to the existing Firebase user.
goToApp();
});
return;
}
// All the other cases are external providers.
// Construct provider object for that provider.
// TODO: implement getProviderForProviderId.
var provider = getProviderForProviderId(methods[0]);
// At this point, you should let the user know that they already has an account
// but with a different provider, and let them validate the fact they want to
// sign in with this provider.
// Sign in to provider. Note: browsers usually block popup triggered asynchronously,
// so in real scenario you should ask the user to click on a "continue" button
// that will trigger the signInWithPopup.
auth.signInWithPopup(provider).then(function(result) {
// Remember that the user may have signed in with an account that has a different email
// address than the first one. This can happen as Firebase doesn't control the provider's
// sign in flow and the user is free to login using whichever account they own.
// Step 4b.
// Link to Google credential.
// As we have access to the pending credential, we can directly call the link method.
result.user.linkAndRetrieveDataWithCredential(pendingCred).then(function(usercred) {
// Google account successfully linked to the existing Firebase user.
goToApp();
});
});
});
}
});
在登录按钮的结果回调函数中，使用 Google 身份验证响应中的 ID 令牌来换取 Firebase 凭据，然后登录 Firebase：
function onSignIn(googleUser) {
console.log('Google Auth Response', googleUser);
// We need to register an Observer on Firebase Auth to make sure auth is initialized.
var unsubscribe = firebase.auth().onAuthStateChanged(function(firebaseUser) {
unsubscribe();
// Check if we are already signed-in Firebase with the correct user.
if (!isUserEqual(googleUser, firebaseUser)) {
// Build Firebase credential with the Google ID token.
var credential = firebase.auth.GoogleAuthProvider.credential(
googleUser.getAuthResponse().id_token);
// Sign in with credential from the Google user.
firebase.auth().signInWithCredential(credential).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
// The email of the user's account used.
var email = error.email;
// The firebase.auth.AuthCredential type that was used.
var credential = error.credential;
// ...
});
} else {
console.log('User already signed-in Firebase.');
}
});
}
function isUserEqual(googleUser, firebaseUser) {
if (firebaseUser) {
var providerData = firebaseUser.providerData;
for (var i = 0; i < providerData.length; i++) {
if (providerData[i].providerId === firebase.auth.GoogleAuthProvider.PROVIDER_ID &&
providerData[i].uid === googleUser.getBasicProfile().getId()) {
// We don't need to reauth the Firebase connection.
return true;
}
}
}
return false;
}
高级：在 Node.js 中进行 Firebase 身份验证
要在 Node.js 应用中进行 Firebase 身份验证，请按以下步骤操作：
使用用户的 Google 帐号登录，获取用户的 Google ID 令牌。为此，您可以采取多种方式。例如：
如果您的应用具有浏览器前端，请按照手动处理登录流程部分的说明，使用 Google 登录功能。从身份验证响应中获取 Google ID 令牌：
var id_token = googleUser.getAuthResponse().id_token
// Build Firebase credential with the Google ID token.
var credential = firebase.auth.GoogleAuthProvider.credential(id_token);
// Sign in with credential from the Google user.
firebase.auth().signInWithCredential(credential).catch(function(error) {
// Handle Errors here.
var errorCode = error.code;
var errorMessage = error.message;
// The email of the user's account used.
var email = error.email;
// The firebase.auth.AuthCredential type that was used.
var credential = error.credential;
// ...
});
