Javascript code for showing facebook login button not working

Question

I have a script to show the facebook login button for some website:

<html>
<head></head>
<body>
<div id="fb-root"></div>
<script>
  window.fbAsyncInit = function() {
  FB.init({
    appId      : 'myID', // App ID
    channelUrl : 'localhost:8080', // Channel File
    status     : true, // check login status
    cookie     : true, // enable cookies to allow the server to access the session
    xfbml      : true  // parse XFBML
  });

  // Here we subscribe to the auth.authResponseChange JavaScript event. This event is fired
  // for any authentication related change, such as login, logout or session refresh. This means that
  // whenever someone who was previously logged out tries to log in again, the correct case below 
  // will be handled. 
  FB.Event.subscribe('auth.authResponseChange', function(response) {
    // Here we specify what we do with the response anytime this event occurs. 
    if (response.status === 'connected') {
      // The response object is returned with a status field that lets the app know the current
      // login status of the person. In this case, we're handling the situation where they 
      // have logged in to the app.
      testAPI();
    } else if (response.status === 'not_authorized') {
      // In this case, the person is logged into Facebook, but not into the app, so we call
      // FB.login() to prompt them to do so. 
      // In real-life usage, you wouldn't want to immediately prompt someone to login 
      // like this, for two reasons:
      // (1) JavaScript created popup windows are blocked by most browsers unless they 
      // result from direct interaction from people using the app (such as a mouse click)
      // (2) it is a bad experience to be continually prompted to login upon page load.
      FB.login();
    } else {
      // In this case, the person is not logged into Facebook, so we call the login() 
      // function to prompt them to do so. Note that at this stage there is no indication
      // of whether they are logged into the app. If they aren't then they'll see the Login
      // dialog right after they log in to Facebook. 
      // The same caveats as above apply to the FB.login() call here.
      FB.login();
    }
  });
  };

  // Load the SDK asynchronously
  (function(d){
   var js, id = 'facebook-jssdk', ref = d.getElementsByTagName('script')[0];
   if (d.getElementById(id)) {return;}
   js = d.createElement('script'); js.id = id; js.async = true;
   js.src = "//connect.facebook.net/en_US/all.js";
   ref.parentNode.insertBefore(js, ref);
  }(document));

  // Here we run a very simple test of the Graph API after login is successful. 
  // This testAPI() function is only called in those cases. 
  function testAPI() {
    console.log('Welcome!  Fetching your information.... ');
    FB.api('/me', function(response) {
      console.log('Good to see you, ' + 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.

  Learn more about options for the login button plugin:
  /docs/reference/plugins/login/ -->

<fb:login-button show-faces="true" width="200" max-rows="1"></fb:login-button>
</body>
</html>

I have gotten this code from:

https://developers.facebook.com/docs/facebook-login/getting-started-web/

I am new to javascript and have copid the script as it is: and pasted it into a .html file which i tried to view using my browser. However I saw nothing. Please advise as im new to this.

Answer 1

If you check the console in the developer tools, you will see this warning from the facebook javascript code:

Invalid App Id: Must be a number or numeric string representing the application id.

Followed by this javascript error:

Uncaught TypeError: Cannot read property '1' of null

You have to replace these two lines in the code with your own data to make it work:

appId      : 'myID', // App ID
channelUrl : 'localhost:8080', // Channel File

You will get the appId when you create a facebook app, as illustrated by the tutorial you are linking to.

Also, you will need to specify the channelUrl to point at a file (eg channel.html containing the following line of code:

<script src="//connect.facebook.net/en_US/all.js"></script>

But read the guide you linked to thoroughly instead of just copy-pasting code blindly, and you will probably both understand it and be able to make it work in a couple of minutes :)

Javascript code for showing facebook login button not working

Question

1 answers

solution1
1 ACCPTED 2013-10-04 13:43:43

Javascript code for showing facebook login button not working

Question

1 answers

solution1 1 ACCPTED 2013-10-04 13:43:43

solution1
1 ACCPTED 2013-10-04 13:43:43