google realtime api -> gapi.auth.authorize -> get email address of user - google-drive-realtime-api

Question

I have a google realtime API web application and I use the "realtime-client-utils.js" library to authenticate that is accessible at GitHub:
https://github.com/googledrive/realtime-utils.
When I call RealtimeUtils.authorize(onAuthComplete, usePopup)
I get a response object for the onAuthComplete callback method. This response object contains information about the authorization process:
But I need the email address of the google user that just authenticated himself. Can anybody tell me how I can get the email address?
I tried to use this tutorial:
https://developers.google.com/+/web/people/#retrieve-an-authenticated-users-email-address

Answer 1

You can try to use the People: get method to get a person's profile. Also, this method returns a person resource in the response body.
Here is the response that you can get by doing this.
{
"kind": "plus#person",
"etag": etag,
"nickname": string,
"occupation": string,
"skills": string,
"birthday": string,
"gender": string,
"emails": [
{
"value": string,
"type": string
}
],
"urls": [
{
"value": string,
"type": string,
"label": string
}
],
"objectType": string,
"id": string,
"displayName": string,
"name": {
"formatted": string,
"familyName": string,
"givenName": string,
"middleName": string,
"honorificPrefix": string,
"honorificSuffix": string
},
"tagline": string,
"braggingRights": string,
"aboutMe": string,
"relationshipStatus": string,
"url": string,
"image": {
"url": string,
},
"organizations": [
{
"name": string,
"department": string,
"title": string,
"type": string,
"startDate": string,
"endDate": string,
"location": string,
"description": string,
"primary": boolean
}
],
"placesLived": [
{
"value": string,
"primary": boolean
}
],
"isPlusUser": boolean,
"language": string,
"ageRange": {
"min": integer,
"max": integer
},
"plusOneCount": integer,
"circledByCount": integer,
"verified": boolean,
"cover": {
"layout": string,
"coverPhoto": {
"url": string,
"height": integer,
"width": integer
},
"coverInfo": {
"topImageOffset": integer,
"leftImageOffset": integer
}
},
"domain": string
}
For more information, check this SO question if it can help you.

Answer 2

There are a few ways to retrieve the user's email address. The easiest is to use the id_token returned on the user's access_token that you receive (#3 below).
1) You can use the UserInfo endpoint after including the 'profile' OAuth scope: https://www.googleapis.com/oauth2/v1/userinfo?alt=json&access_token=[token]. Making a dirty query to this API with your access token will return the user's email address.
2) As noted in a different answer, you can use the People.Get API.
3) (In my opinion the best option) Request and use the id_token (JWT) that can be returned along with a valid Google Access Token. For this you must include the 'https://www.googleapis.com/auth/userinfo.email' OAuth scope, and when making the call for Google Authorization, the 'response_type' param must be set to 'token id_token'. You can do this by editing the Realtime API to pass in 'response_type: "token id_token" along with the other params to gapi.auth.authorize.
Once you have your id_token, it needs to be decoded. You can use the code below and just pass in the response object that you receive. The resulting decoded id_token will contain the user's email address.
function decodeJWT(rawToken)
{
var decoded;
if (rawToken && rawToken.id_token)
{
var jwt = rawToken.id_token;
var parts = jwt.split('.');
try
{
decoded = JSON.parse(b64_to_utf8(parts[1]));
}
catch (err)
{
// Handle Error
}
}
return decoded;
}
function b64_to_utf8(str)
{
var utf8;
try
{
utf8 = decodeURIComponent(escape(window.atob(str)));
}
catch (err)
{
// Handle Error
}
return utf8;
}
Good luck!