Google登录按钮电子邮件字段

Question

I have set up my simple Google Sign-in button from the tutorial https://developers.google.com/+/web/signin/ and I was wondering if how I can do the following:

1. Restrict all domains in the email field except for something like @domain.com So johndoe@gmail.com will not work, but johndoe@twitter.com would be accepted. Makes sense?

2. Is it possible to "force" the user to sign in again if the the user is already logged into a Google account?

Here is my Javascript / jQuery code:

<script type="text/javascript">

      (function() {
       var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true;
       po.src = 'https://apis.google.com/js/client:plusone.js';
       var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s);
     })();


  function signinCallback(authResult) {
  if (authResult['access_token']) {
    // Successfully authorized
    // Hide the sign-in button now that the user is authorized, for example:
    document.getElementById('signinButton').setAttribute('style', 'display: none');

    $('.inline-field-title').hide();


  } else if (authResult['error']) {
    // There was an error.
    // Possible error codes:
    //   "access_denied" - User denied access to your app
    //   "immediate_failed" - Could not automatically log in the user
    // console.log('There was an error: ' + authResult['error']);
  }
}


  function disconnectUser(access_token) {
  var revokeUrl = 'https://accounts.google.com/o/oauth2/revoke?token=' +
      access_token;

  // Perform an asynchronous GET request.
  $.ajax({
    type: 'GET',
    url: revokeUrl,
    async: false,
    contentType: "application/json",
    dataType: 'jsonp',
    success: function(nullResponse) {
      // Do something now that user is disconnected
      // The response is always undefined.
    },
    error: function(e) {
      // Handle the error
      // console.log(e);
      // You could point users to manually disconnect if unsuccessful
      // https://plus.google.com/apps
    }
  });

}
// Could trigger the disconnect on a button click

$('#revokeButton').click(disconnectUser);


</script>

Answer 1

Ad 1) You would have to check the email after login manually and act accordingly if the email doesn't match whatever domain you are looking for.

To do this you would have to request an additional scope https://www.googleapis.com/auth/userinfo.email which you can define in the data-scope parameter of your Sign-in button markup, and after authentication do an authenticated request for https://www.googleapis.com/oauth2/v2/userinfo which will return the email address in the response.

See https://developers.google.com/+/web/people/#retrieve_an_authenticated_users_email_address for some sample code.

Ad 2) The sign-in button accepts a parameter data-approvalprompt="force" that will show the authentication dialog (and let a user switch to a different account) on each sign-in attempt.

See https://developers.google.com/+/web/signin/#sign-in_button_attributes