Google login demo using gapi
var startApp = function () {
gapi.load('auth2', function () {
auth2 = gapi.auth2.init({
// Change this to your Google ID
client_id: 'YOUR_GOOGLE_ID.apps.googleusercontent.com',
cookiepolicy: 'single_host_origin',
});
attachSignin(document.getElementById('btnGoogle'));
});
};