John Doe likes a link
| http://www.mysite.com/my_app?app_data=abcdef123

<div class="fb-like" data-href="http://apps.facebook.com/my_app/?app_data=<?php
echo urlencode(base64_encode(json_encode($app_data))); ?>" data-send="true" data-layout="button_count" data-width="150" data-show-faces="false" data-font="arial"></div>