This is a modification that I made to share topics on facebook, I am using kunena 3.03, theme blue_eagle
Edit /components/com_kunena/template/blue_eagle/html/topic/default.php
Before:
<div class="kblock">
<div class="kheader">
<h2><span><?php echo JText::_('COM_KUNENA_TOPIC') ?> <?php echo $this->escape($this->topic->subject) ?></span></h2>
After:
<div class="kblock">
<div class="kheader">
<h2><span><?php echo JText::_('COM_KUNENA_TOPIC') ?> <?php echo $this->escape($this->topic->subject) ?></span><div id="facebook_share">
<!-- Agregado para facebook -->
<?php
function curPageURL() {
$pageURL = 'http';
if ($_SERVER["HTTPS"] == "on") {$pageURL .= "s";}
$pageURL .= "://";
if ($_SERVER["SERVER_PORT"] != "80") {
$pageURL .= $_SERVER["SERVER_NAME"].":".$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
} else {
$pageURL .= $_SERVER["SERVER_NAME"].$_SERVER["REQUEST_URI"];
}
return $pageURL;
}
?>
<a onclick="window.open('https://www.facebook.com/share.php?u=<?php echo curPageURL(); ?>', '_blank', 'height=365,width=660'); return false;"href="https://www.facebook.com/share.php?u=<?php echo curPageURL(); ?>” target="_blank" style="float: right; margin-top: -25px;"><img src="https://www.rcnmundo.com/img/comparte.jpg" title="Compartir"></a>
<div></h2>
first a PHP function to get the page (URL) of the message and then a javascript function that opens a popup window that leads to facebook and automatically passes the URL to share.