如何在joomla中用php动态设置og：image元标记？

Question

I'm trying to dynamically set the og:image meta tag for a joomla 1.5 website with a logic on a part of the url.

This is the code:

<?php 
$actual_link = "http://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]"; 
if (strpos($actual_link,'basket') !== false) { 
?>

<meta property="og:image" content="http://astel-teglio.it/site/images/Basketball.png" />

<?php
}else{
?>

<meta property="og:image" content="http://astel-teglio.it/site/images/LOGO.jpg" />

<?php
}
?>

The logic is very simple, if the url contains basket I want to use the image Basketball.png, else LOGO.jpg.

If I watch the source code in the browser I see the right attribute but when a paste the link on facebook I always see the Logo image (else case).

There are the two sample pages:

• link with basket in the url (then case)
• link without basket in the url (else case)

Answer 1

In Joomla you can dynamically set og:attributes or meta tags like below.

$doc =& JFactory::getDocument();
if($shareTitle != '')
    $doc->addCustomTag( '<meta property="og:title" content="'.$shareTitle.'" />'  );
if($shareDesc != '')
    $doc->addCustomTag( '<meta property="og:description" content="'.$shareDesc.'" />' );
if($shareImg != '')
    $doc->addCustomTag( '<meta property="og:image" content="'.$shareImg.'" />' );

You can also check How to set meta data of a page in joomla .

Also facebook have cache issue, you can debug here .

Hope this helps..

Answer 2

I think that the problem is caused by the SEF URLs that change my url from:

http://astel-teglio.it/site/index.php?option=com_content&view=article&id=317

to:

http://astel-teglio.it/site/it/minibasket/stagione-20132014/scoiattoli/317--morbegno--molino-tudori-teglio-12-12.html

but when facebook loads the meta tags it load the original url that hasn't basket in the url string and so it loads the standard image.