<!DOCTYPE html> <html> <head> <title>Facebook Login JavaScript Example</title> <meta charset="UTF-8"> </head> <body> <script>   // This is called with the results from from FB.getLoginStatus().   function statusChangeCallback(response) {     console.log('statusChangeCallback');     console.log(response);     // The response object is returned with a status field that lets the     // app know the current login status of the person.     // Full docs on the response object can be found in the documentation     // for FB.getLoginStatus().     if (response.status === 'connected') {       // Logged into your app and Facebook.       testAPI();     } else if (response.status === 'not_authorized') {       // The person is logged into Facebook, but not your app.       document.getElementById('status').innerHTML = 'Please log ' +         'into this app.';     } else {       // The person is not logged into Facebook, so we're not sure if       // they are logged into this app or not.       document.getElementById('status').innerHTML = 'Please log ' +         'into Facebook.';     }   }    // This function is called when someone finishes with the Login   // Button.  See the onlogin handler attached to it in the sample   // code below.   function checkLoginState() {     FB.getLoginStatus(function(response) {       statusChangeCallback(response);     });   }    window.fbAsyncInit = function() {   FB.init({     appId      : '{your-app-id}',     cookie     : true,  // enable cookies to allow the server to access                          // the session     xfbml      : true,  // parse social plugins on this page     version    : 'v2.1' // use version 2.1   });    // Now that we've initialized the JavaScript SDK, we call    // FB.getLoginStatus().  This function gets the state of the   // person visiting this page and can return one of three states to   // the callback you provide.  They can be:   //   // 1. Logged into your app ('connected')   // 2. Logged into Facebook, but not your app ('not_authorized')   // 3. Not logged into Facebook and can't tell if they are logged into   //    your app or not.   //   // These three cases are handled in the callback function.    FB.getLoginStatus(function(response) {     statusChangeCallback(response);   });    };    // Load the SDK asynchronously   (function(d, s, id) {     var js, fjs = d.getElementsByTagName(s)[0];     if (d.getElementById(id)) return;     js = d.createElement(s); js.id = id;     js.src = "//connect.facebook.net/en_US/sdk.js";     fjs.parentNode.insertBefore(js, fjs);   }(document, 'script', 'facebook-jssdk'));    // Here we run a very simple test of the Graph API after login is   // successful.  See statusChangeCallback() for when this call is made.   function testAPI() {     console.log('Welcome!  Fetching your information.... ');     FB.api('/me', function(response) {       console.log('Successful login for: ' + response.name);       document.getElementById('status').innerHTML =         'Thanks for logging in, ' + response.name + '!';     });   } </script>  <!--   Below we include the Login Button social plugin. This button uses   the JavaScript SDK to present a graphical Login button that triggers   the FB.login() function when clicked. -->  <fb:login-button scope="public_profile,email" onlogin="checkLoginState();"> </fb:login-button>  <div id="status"> </div>  </body> </html>