Uncaught ReferenceError: FB is not defined

javascript php jquery facebook facebook-javascript-sdk

44,703

See this thread: FB is not defined in Facebook Login.

You are trying to use FB right after your button, and it's not defined yet:

<fb:like href="http://mydomain.it/" layout="button_count" action="like" show_faces="false" share="false"></fb:like>
<script>
FB.Event.subscribe(...
^--- FB isn't defined yet!

Move that FB.Event.subscribe code inside your window.fbAsyncInit function, where you have that comment "Additional initialization code"

44,703

Francesco Mineo

I love coding :)

Updated on July 09, 2022

Comments

Francesco Mineo almost 2 years

I know this question is asked frequently, but I have not found the solution. I use this code:

open the html tag with

<html xmlns="http://www.w3.org/1999/xhtml" xmlns:fb="http://ogp.me/ns/fb#">

in the index immediately after the opening tag I entered this

<div id="fb-root"></div>
<script>
  window.fbAsyncInit = function() {
    // init the FB JS SDK
    FB.init({
      appId      : 'MY_APP_ID',                        // App ID from the app dashboard
      status     : true,                                 // Check Facebook Login status
      xfbml      : true                                  // Look for social plugins on the page
    });

    // Additional initialization code such as adding Event Listeners goes here
  };

  // Load the SDK asynchronously
  (function(){
     // If we've already installed the SDK, we're done
     if (document.getElementById('facebook-jssdk')) {return;}

     // Get the first script element, which we'll use to find the parent node
     var firstScriptElement = document.getElementsByTagName('script')[0];

     // Create a new script element and set its id
     var facebookJS = document.createElement('script'); 
     facebookJS.id = 'facebook-jssdk';

     // Set the new script's source to the source of the Facebook JS SDK
     facebookJS.src = '//connect.facebook.net/it_IT/all.js';

     // Insert the Facebook JS SDK into the DOM
     firstScriptElement.parentNode.insertBefore(facebookJS, firstScriptElement);
   }());
</script>

finally, the button

<fb:like href="http://mydomain.it/" layout="button_count" action="like" show_faces="false" share="false"></fb:like>
<script>
FB.Event.subscribe('edge.create',
 function(href, widget) {
    alert('Ti piace ' + href);
});
</script>

the like works, but does not open the alert and I got this error in console.

Uncaught ReferenceError: FB is not defined

Any solutions?

CBroe over 10 years

In your last code block, you are calling the method immediately, without waiting for the SDK to be initialized. Place that call inside the fbAsyncInit handler after the initialization.