Trying to get the status of firebase user authentication - javascript

I have an authentication function using firebase which is just the auth code from the firebase documentation
export const signIn = (email,password) => {
firebase.auth().signInWithEmailAndPassword(email, password).then(()=>{
alert('Sign in Successful!')
}).catch(function(error) {
alert(error.message)
});
}
I call it like this
signIn(mail, password)
When I call it in my code, It works perfectly and the proper alerts appear. However, I want to actually receive something from my authentication function, like True or False if the user successfully logged in or not. Is there a way for me to receive this value from my function or any workarounds?
//evaluates to True if logged in successfully and vice versa
let authState = signIn(this.mail, this.password)

There's a couple approaches you could take with this, the first that comes to mind is the following:
export const signIn = (email, password) => {
return firebase.auth().signInWithEmailAndPassword(email, password).then(userCredential => {
alert('Sign in Successful!');
return true;
}).catch(error => {
alert(error.message);
return false;
});
}
// ......
let authState = await signIn(this.mail, this.password);
In promises you're able to return values from the .then() or .catch() method and then use that resolved value further in your code.

If you want to know when a user is signed in, no matter how they were signed in, you should instead use an auth state observer to set up a callback that will be invoked whenever the user becomes signed in or out, as shown in the documentation:
firebase.auth().onAuthStateChanged(function(user) {
if (user) {
// User is signed in.
} else {
// User is signed out.
}
});

Related

Password is gone when logging in a firebase account that was created using Email and Password

I created an app that supports both Email/Password and Google authentication. I found that if I created an account in a first way, but logged out and in again with Google, the origin password was gone, and no way to sign in with email anymore. Is there any way to avoid so?
// Google authentication
const signInWithGoogle = useCallback(
async event => {
event.preventDefault();
const provider = new firebase.auth.GoogleAuthProvider();
try {
await firebaseApp
.auth()
.signInWithRedirect(provider)
.then(function(result) {
var user = result.user.providerId;
alert(user);
});
history.push("/transfer");
} catch(error) {
alert(error.message);
}
},
[history]
);
//Email/Password sign-in
const handleLogin = useCallback(
async event => {
event.preventDefault();
const { email, password } = event.target.elements;
try {
await firebaseApp
.auth()
.signInWithEmailAndPassword(email.value, password.value)
.then(function(result) {
var user = result.user.providerId;
alert(user);
});
history.push("/transfer");
} catch (error) {
alert(error);
}
},
[history]
);
// Email/Password sign-up
const handleSignUp = useCallback(async event => {
event.preventDefault();
const { email, password } = event.target.elements;
try {
await firebaseApp
.auth()
.createUserWithEmailAndPassword(email.value, password.value);
history.push("/usersignupcred");
} catch (error) {
alert(error);
}
}, [history]);
Here in the documentation you can see this explanation:
Note that some providers, such as Google and Microsoft, serve as both email and social identity providers. Email providers are considered authoritative for all addresses related to their hosted email domain. This means a user logging in with an email address hosted by the same provider will never raise this error (for example, signing in with Google using an #gmail.com email, or Microsoft using an #live.com or #outlook.com email).
I would recommend to use as similar approach like here from the docu:
// User tries to sign in with Facebook.
auth.signInWithPopup(new firebase.auth.FacebookAuthProvider()).catch(err => {
// User's email already exists.
if (err.code === 'auth/account-exists-with-different-credential') {
// The pending Facebook credential.
var pendingCred = err.credential;
// The provider account's email address.
var email = err.email;
// Get the sign-in methods for this email.
auth.fetchSignInMethodsForEmail(email).then(methods => {
// 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') {
// TODO: Ask the user for their password.
// In real scenario, you should handle this asynchronously.
var password = promptUserForPassword();
auth.signInWithEmailAndPassword(email, password).then(result => {
return result.user.linkWithCredential(pendingCred);
}).then(() => {
// Facebook account successfully linked to the existing user.
goToApp();
});
return;
}
// All 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 have an
// account with a different provider, and validate they want to sign in
// with the new provider.
// Note: Browsers usually block popups triggered asynchronously, so in
// real app, you should ask the user to click on a "Continue" button
// that will trigger signInWithPopup().
auth.signInWithPopup(provider).then(result => {
// Note: Identity Platform doesn't control the provider's sign-in
// flow, so it's possible for the user to sign in with an account
// with a different email from the first one.
// Link the Facebook credential. We have access to the pending
// credential, so we can directly call the link method.
result.user.linkWithCredential(pendingCred).then(usercred => {
// Success.
goToApp();
});
});
});
}
});
But instead of waiting for the error to be raised (none will be raised if using Google login as you also explained in your case) try always to call first fetchSignInMethodsForEmail and if the user has the email provider and tries now to use the Google one first log him in with the email provider and link him later with the Google provider.

Send verification email before logging in

This is the code that i'm practicing in to create a new user. I can receive the email verification and confirm it however, the site will still logged me in even if I have not yet confirmed my email yet.
try{
const { user } = await auth.createUserWithEmailAndPassword(email,password);
await user.sendEmailVerification();
await handleUserProfile(user, { displayName});
this.setState({
...initialSate
});
}catch(err){
console.log(err);
}
}
This is the handleUserProfile in another js file.
export const handleUserProfile = async (userAuth, additionalData) => {
if (!userAuth) return;
const {uid} = userAuth;
const userRef = firestore.doc(`users/${uid}`);
//create new user
const snapshot = await userRef.get();
if (!snapshot.exists){
const { displayName, email} = userAuth;
const timestamp = new Date();
//if the user exist does not exist
try{
await userRef.set({
displayName,
email,
createdDate: timestamp,
...additionalData
});
}catch(err){
console.log(err);
}
}
return userRef;
};
Everything is explained in the firebase documentation.
There you have the corresponding code snippets to try.
You would need to narrow down your question with some of this trials.
Even you have the chance to check if user opens the link from a differenc device from which waas signed up.
I think this is the snippet you might need:
// Confirm the link is a sign-in with email link.
if (firebase.auth().isSignInWithEmailLink(window.location.href)) {
// Additional state parameters can also be passed via URL.
// This can be used to continue the user's intended action before triggering
// the sign-in operation.
// Get the email if available. This should be available if the user completes
// the flow on the same device where they started it.
var email = window.localStorage.getItem('emailForSignIn');
if (!email) {
// User opened the link on a different device. To prevent session fixation
// attacks, ask the user to provide the associated email again. For example:
email = window.prompt('Please provide your email for confirmation');
}
// The client SDK will parse the code from the link for you.
firebase.auth().signInWithEmailLink(email, window.location.href)
.then((result) => {
// Clear email from storage.
window.localStorage.removeItem('emailForSignIn');
// You can access the new user via result.user
// Additional user info profile not available via:
// result.additionalUserInfo.profile == null
// You can check if the user is new or existing:
// result.additionalUserInfo.isNewUser
})
.catch((error) => {
// Some error occurred, you can inspect the code: error.code
// Common errors could be invalid email and invalid or expired OTPs.
});
}
The site will still logged me in even if I have not yet confirmed my
email yet.
Yes this is how it is implemented in Firebase: there is nothing, out of the box, that prevents a user with a non-verified email to authenticate to your app.
You should manage that yourself, by:
Checking the email is verified in the back-end security rules (Firestore, Cloud Storage, etc..). For example with a function like:
function isVerifiedEmailUser() {
return request.auth.token.email_verified == true;
}
Possibly redirect and logout the user from your app if his/her email is not verified. For example, right after signing-up, as follows:
try {
const { user } = await auth.createUserWithEmailAndPassword(email,password);
await user.sendEmailVerification();
if (user.emailVerified) {
// display the content, redirect to another page, etc...
} else {
auth.signOut(); // Maybe call that after showing an error message
}
} catch(err){
console.log(err);
}
}
plus, potentially, something similar with signInWithEmailAndPassword() and onAuthStateChanged().

How to detect the user's firebase authentication login status in a vue js project?

I am trying to detect the userstate. If the user is logged in I want to set the data "userstate" to true. I am using vuefire and firebase into my vue project. I tried the way shown below, but it does not work
data() {
return {
userstate:false
};
},
watch:{
userstate:{
firebase.auth().onAuthStateChanged(function(user){
if(user){
this.userstate= true;}
else{
this.userstate=false;
}
})}
In Firebase you can check whether the user is signed in or not by using a function provided by the firebase which is auth().currentUser
// user will return true which means user EXISTS!
let user = firebase.auth().currentUser;
if (user) {
this.userstate = true; // If it exists
} else {
this.userstate = false; // If it doesn't
}
There are cases when the above mentioned method returns null / undefined for the user. So this solution is for your existing solution. So in that case try modifying your existing function to this:
async function IsLoggedIn() {
try {
await new Promise((resolve, reject) =>
firbase.auth().onAuthStateChanged(
user => {
if (user) {
// Yes User is signed in.
resolve('User is there');
} else {
// No user is not signed in.
reject('There is no user');
}
},
// Prevent console errors
error => reject(error)
)
)
return true
} catch (error) {
return false
}
}
Also since you intend to watch for the auth state change you can simply register the listener right after you initialize Firebase, you do not necessarily have to insert it in a VueJS watch block, you can insert it in your main.js for example, and if you are using a store like VueX you can update the state in the store and pull that information from any component of the VueX application.
firebase.initializeApp(configOptions);
firebase.auth().onAuthStateChanged(user => {
if (user) {
this.userstate = true;
} else {
this.userstate = false;
}
});

How to validate firebase user current password

I am creating a form, in react-redux to change user password. I am wondering how can I validate the user current password in order to change to new one.
in my form I have 2 fields: old password, new password.
this is my action:
const { currentUser } = auth
currentUser.updatePassword(newPassword)
.then(
success => {
dispatch({
type: CHANGE_USER_PASSWORD_SUCCESS,
payload: currentUser
})
},
error => {
dispatch({
type: CHANGE_USER_PASSWORD_FAIL,
error: error.message
})
}
)
I am wondering, how to validate the old password in firebase? Should I use signInWithEmailAndPassword()? Or, is there a function to validate the current password without calling the signIn again, since my user is already logged in?
Thanks
Well, I believe you want the user to enter the old password just to verify whether it's the actual owner of the account or not.
Firebase handles this situation very well, you just need to call the updatePassword method on the user object and pass in the new password.
const changePassword = async newPassword => {
const user = firebase.auth().currentUser;
try {
await user.updatePassword(newPassword)
console.log('Password Updated!')
} catch (err) {
console.log(err)
}
}
If it's been quite a while that the user last logged in then firebase will return back an error -
"This operation is sensitive and requires recent authentication. Log in before retrying this request."
Thus, you don't really need to check the old password as firebase does it for you.
But if you just want to do it in one go, without having the user to log in again.
There's a way for that as well.
There is a method on user object reauthenticateAndRetrieveDataWithCredential you just need to pass in a cred object(email and password) and it refreshes the auth token.
const reauthenticate = currentPassword => {
const user = firebase.auth().currentUser;
const cred = firebase.auth.EmailAuthProvider.credential(
user.email, currentPassword);
return user.reauthenticateAndRetrieveDataWithCredential(cred);
}
In your particular case, you can have something like this
const changePassword = async (oldPassword, newPassword) => {
const user = firebase.auth().currentUser
try {
// reauthenticating
await this.reauthenticate(oldPassword)
// updating password
await user.updatePassword(newPassword)
} catch(err){
console.log(err)
}
}
Learn more about firebase reauth - https://firebase.google.com/docs/auth/web/manage-users#re-authenticate_a_user
Hope it helps

React's SetState within Firebase Auth's onAuthStateChanged causing setState to be undefined

//Why this question isn't a duplicate of (How to access the correct `this` inside a callback?) : my question is a react-specific question and visitors might not mentally connect the dots between the issue raised in the above link and what I'm struggling with.
I'm trying to store the user data returned by Firebase auth's onAuthStateChanged function and store that data in state to work with it in my react app. In my app, I have the below listener:
componentDidMount() {
firebase.auth().onAuthStateChanged(function(user) {
var theUser;
if (user) {
console.log("user is logged in!");
theUser = user;
this.setState({
session: theUser
});
// User is signed in.
} else {
// No user is signed in.
console.log("user is not logged in!")
theUser = null;
}
}
}
But I get the error "TypeError: this.setState is not a function". I've tried binding "this" to componentDidMount to no avail.
As #Jason Byrne said it seems to a problem specifying who is "this" and you can follow the approach he mentioned in his answer.
Another modern approach is to use ES6 arrow functions as they work in lexical scope, so this is determined depending on "where" it is written (which is your class):
componentDidMount() {
firebase.auth().onAuthStateChanged(user => {
var theUser;
if (user) {
console.log("user is logged in!");
theUser = user;
this.setState({
session: theUser
});
// User is signed in.
} else {
// No user is signed in.
console.log("user is not logged in!")
theUser = null;
}
}
}
Also have a look here: How to access the correct `this` inside a callback?
"this" in JavaScript can be a bit difficult, you have to be sure you know what this is referring to. Because the "this" is inside of the "function(user)" it is relative to that function... not your application as a whole. I'd have to see you whole code to be sure, but you can do something like this to hold on to a reference of your application and use that instead.
let myApp = this;
componentDidMount() {
firebase.auth().onAuthStateChanged(function(user) {
var theUser;
if (user) {
console.log("user is logged in!");
theUser = user;
myApp.setState({
session: theUser
});
// User is signed in.
} else {
// No user is signed in.
console.log("user is not logged in!")
theUser = null;
}
}
}

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