Question

I am trying to use a Facebook Like button via an iFrame, like so:

<iframe id="test" src="http://www.facebook.com/plugins/like.php? 
       href=http://yoururl.com/&amp;
       layout=button_count&amp;
       show_faces=false&amp;
       width=50&amp;
       action=like&amp;
       colorscheme=light&amp;
       height=21" 
       scrolling="no" frameborder="0" 
       style="border:none; overflow:hidden; width:50px;  
              height:21px;" 
       allowTransparency="true">

After a user clicks “Like” for the first time, I want to execute some Javascript in my DOM content. How would I go about doing this?

Answer 1

You mean you want to execute some Javascript when you like something?

You can use the Facebook Javascript SDK for that, especially the edge.create event.
See

1. http://developers.facebook.com/docs/reference/javascript/ (for general SDK doc)
2. http://developers.facebook.com/docs/reference/javascript/FB.Event.subscribe/ (for event doc)

This should work with the IFrame-version too. If not, you have to switch to the XFBML-Like button. It definetly works with the XFBML version.

Example:

<!-- Load the SDK (or even better, load it asynchronously. See first link above -->
<div id="fb-root"></div>
<script src="http://connect.facebook.net/en_US/all.js"></script>
<script>
// initalize your Facebook App
  FB.init({
    appId  : 'YOUR APP ID',
    status : true, // check login status
    cookie : true, // enable cookies to allow the server to access the session
    xfbml  : true  // parse XFBML
  });
// subscribe to the event
FB.Event.subscribe('edge.create', function(response) {
  alert('you liked this');
});
FB.Event.subscribe('edge.remove', function(response) {
  alert('you unliked this');
});
</script>
<!--
    The XFBML Like Button, if the iframe version doesn't work (not 100% sure)
    <fb:like></fb:like>
 -->