OAuth HTML+JS example

<head>
    <meta name="google-signin-scope" content="profile email">
    <meta name="google-signin-client_id" content="#HgetClientId()#">
    <script src="https://apis.google.com/js/platform.js" async defer></script>

...
<body>
Please log in with your Google account to access content! If you found this page accidentally then most likely you have no access rights on this page.
    <div class="g-signin2" data-onsuccess="onSignIn" data-theme="dark"></div>
    <script>
    function send(FD)
    {
    		var xhr = new XMLHttpRequest();
			xhr.qpage=this;
			xhr.responseType = "text";
			xhr.onreadystatechange = function() {
				if (this.readyState == 4) {
					if(this.status == 200)
					{
						var page=this.qpage;
						eval(this.responseText);
					}
					else
					{
						this.qpage.dispose("Server communication XHR fault. Status code: "+this.status);
					}
				}
			}.bind(xhr);
			xhr.open("POST",'?login=true');
			xhr.send(FD);
    }
      function onSignIn(googleUser) {
      	var fd = new FormData();

        var profile = googleUser.getBasicProfile();
        console.log("Google API login attempt: ID: " + profile.getId());
        console.log("ID: " + profile.getId());
        console.log('Full Name: ' + profile.getName());
        console.log('Given Name: ' + profile.getGivenName());
        console.log('Family Name: ' + profile.getFamilyName());
        console.log("Image URL: " + profile.getImageUrl());
        console.log("Email: " + profile.getEmail());
        fd.append("id_token", googleUser.getAuthResponse().id_token);
        var id_token = googleUser.getAuthResponse().id_token;
        console.log("ID Token: " + id_token);
        send(fd);
      };
    </script>
    <a href="#" onclick="signOut();">Sign out</a><br/>
    <a href="#HFotok.clargs.contextPath#/listing/">enter</a>
<script>
  function signOut() {
        var fd=new FormData();
        fd.append("signout", "true");
     	send(fd);
    	var auth2 = gapi.auth2.getAuthInstance();
    	auth2.signOut().then(function () {
    });
  }
</script>