i have gone through this documentation :- https://developers.google.com/identity/sign-in/web/server-side-flow
At the last step it receives the authorization code and
Google APIs Node.js Client library offers oauth2Client.getToken(code, cb) which gives access token (and optionally refresh token) in exchange of the authorization code :
oauth2Client.getToken(code, function (err, tokens) {
// Now tokens contains an access_token and an optional refresh_token. Save them.
if (!err) {
oauth2Client.setCredentials(tokens);
}
});
An official example is available at https://github.com/google/google-api-nodejs-client/tree/master/samples which includes oauth2.js, an helper for the oauth part
You can also find a complete example on this site by Paul Shan, it's a nodejs example using Google APIs Node.js Client. Edit ClientId
and ClientSecret
, run this sample and go to http://127.0.0.1:8081
var http = require('http');
var express = require('express');
var Session = require('express-session');
var google = require('googleapis');
var plus = google.plus('v1');
var OAuth2 = google.auth.OAuth2;
const ClientId = "YOUR_CLIENT_ID";
const ClientSecret = "YOUR_CLIENT_SECRET";
const RedirectionUrl = "http://localhost:8081/oauthCallback";
var app = express();
app.use(Session({
secret: 'raysources-secret-19890913007',
resave: true,
saveUninitialized: true
}));
function getOAuthClient() {
return new OAuth2(ClientId, ClientSecret, RedirectionUrl);
}
function getAuthUrl() {
var oauth2Client = getOAuthClient();
// generate a url that asks permissions for Google+ and Google Calendar scopes
var scopes = [
'https://www.googleapis.com/auth/plus.me'
];
var url = oauth2Client.generateAuthUrl({
access_type: 'offline',
scope: scopes,
//use this below to force approval (will generate refresh_token)
//approval_prompt : 'force'
});
return url;
}
app.use("/oauthCallback", function(req, res) {
var oauth2Client = getOAuthClient();
var session = req.session;
var code = req.query.code;
oauth2Client.getToken(code, function(err, tokens) {
console.log("tokens : ", tokens);
// Now tokens contains an access_token and an optional refresh_token. Save them.
if (!err) {
oauth2Client.setCredentials(tokens);
session["tokens"] = tokens;
res.send(`
<html>
<body>
<h3>Login successful!!</h3>
<a href="/details">Go to details page</a>
<body>
<html>
`);
} else {
res.send(`
<html>
<body>
<h3>Login failed!!</h3>
</body>
</html>
`);
}
});
});
app.use("/details", function(req, res) {
var oauth2Client = getOAuthClient();
oauth2Client.setCredentials(req.session["tokens"]);
var p = new Promise(function(resolve, reject) {
plus.people.get({ userId: 'me', auth: oauth2Client }, function(err, response) {
console.log("response : ", response);
resolve(response || err);
});
}).then(function(data) {
res.send(`<html><body>
<img src=${data.image.url} />
<h3>Hello ${data.displayName}</h3>
</body>
</html>
`);
})
});
app.use("/", function(req, res) {
var url = getAuthUrl();
res.send(`
<html>
<body>
<h1>Authentication using google oAuth</h1>
<a href=${url}>Login</a>
</body>
</html>
`)
});
var port = 8081;
var server = http.createServer(app);
server.listen(port);
server.on('listening', function() {
console.log(`listening to ${port}`);
});