Simple email verification in React Native and Firebase - firebase

Question

I made a simple registration form in React Native. I want to check if the email is valid or not by sending a verification code to it. I read many similar questions but I couldn't combine them with my code because I'm new to React Native. Can anyone help me do that without just posting a link for another answer?
Here's my registration code:
export class Register extends Component {
constructor(props) {
super(props);
this.state = {
email: '',
password: '',
name: '',
lastname: ''
}
this.onSignUp = this.onSignUp.bind(this)
}
onSignUp(){
if(
this.state.email != '' &&
this.state.password != '' &&
this.state.name != ''
){
const { email, password, name } = this.state;
firebase.auth().createUserWithEmailAndPassword(email, password)
.then((result) => {
firebase.firestore().collection("Users")
.doc(firebase.auth().currentUser.uid)
.set({
name,
email
})
console.log(result)
})
.catch((error) => {
console.log(error)
})
}
else{
alert("Please fill the empty spaces!");
}
}
render() { form body }

Answer 1

You cannot verify user email using before creating the account by using Client SDK only. If you need to do that, you will have to use Cloud Functions (or your own server) along with a third party email sending service and implement your own logic.
However you can verify the email of user by sending the user a verification email like this:
//new user created
var user = firebase.auth().currentUser;
user.sendEmailVerification().then(function() {
// Email sent.
}).catch(function(error) {
// An error happened.
});
This will send an email to your user containing a verification link. Thereafter you can use emailVerified property to check if user has verified their email to restrict access to data like:
if (user.emailVerified) {
// process
} else {
alert("Please verify your email")
}
In you case, the code would look like:
const { email, password, name } = this.state;
firebase.auth().createUserWithEmailAndPassword(email, password)
.then(async (result) => {
await firebase.firestore().collection("Users")
.doc(firebase.auth().currentUser.uid)
.set({
name,
email
})
await user.sendEmailVerification()
console.log("Verification Email Sent")
})