How to get user email using Google Sign In expo Auth Session? - react-native

Question

At moment im using this snippet of code to sign in to google, but i cant get user email… anyone know how to do this?
var LoginGoogle = () => {
const [request, response, promptAsync] = Google.useAuthRequest({
androidClientId: 'xxxxxxx.apps.googleusercontent.com',
expoClientId: 'xxxxxxx.apps.googleusercontent.com'
},{
scopes: ["email"]
},{});
React.useEffect(() => {
if (response?.type === 'success') {
const { authentication } = response;
console.log(response);
}
}, [response]);
return (
<GoogleSocialButton disabled={!request} onPress={() => {promptAsync()}} />
)
}
response returns object with links instead of email

Answer 1

I wish this is written in the expo docs. I would like to add a few points from the first answer:
First if you need code snippets on how to fetch user data after getting the access token, you can refer to this github issue: https://github.com/expo/expo/issues/8384
access token can be received by the following code after receiving the response object:
const { authentication: { accessToken } } = response;
then, you can create a function like this:
async function fetchUserInfo(token) {
const response = await fetch('https://www.googleapis.com/oauth2/v3/userinfo', {
method: 'GET',
headers: {
Accept: 'application/json',
Authorization: `Bearer ${token}`,
'Content-Type': 'application/json'
},
});
return await response.json();
}
and get the user object (which contains the user email, profile, photo, etc) by something like this inside an async function:
const user = await fetchUserInfo(accessToken);
But NOTE for the user object, using https://www.googleapis.com/oauth2/v2/userinfo and https://www.googleapis.com/oauth2/v3/userinfo, will yield slightly different result/object ; in particular for v3, since Google implements the OpenID Connect API, there is no "id" attribute anymore, "id" will be called "sub".
sources:
How to identify a Google OAuth2 user?
https://developers.google.com/assistant/identity/google-sign-in-oauth
https://github.com/expo/expo/issues/8384
Example of a user object in v3:
Object {
"email": "xxxxx#gmail.com",
"email_verified": true,
"family_name": "John Deer",
"given_name": "John",
"hd": "gmail.com",
"locale": "en",
"name": "John Deer",
"picture": "https://lh3.googleusercontent.com/a/asdfjasdklfjaslkf",
"sub": "10998837733652322",
}
Hope this helps someone in the future...!
EDIT: if you need the id_token checkout this one:
expo-auth-session/providers/google Google.useAuthRequest

Answer 2

I am using AuthSession as well in my RN app and I stumbled with this problem. After going through Google API Docs, found out you can pass the access token from the useAuthRequest response to https://www.googleapis.com/oauth2/v3/userinfo?access_token= ACCESS_TOKEN.