Hi Markus,

So far, this is unexplored territory This functionality is not built in to Chameleon, and I've had to look carefully inside Joomla to find some work-arounds.

Here's what I found:

1 - if the article is directly linked from a menu item, you can use this in the SUCCEED action in Chameleon to set the new layout. The layout is made of 2 parts: the template name and the name of the file with the alternative layout.

$app = JFactory::getApplication('site');
$active    = $app->getMenu()->getActive();
$active->query['layout'] = "beez_20:alternative";

2 - if the article is not directly linked from a menu item, then as far as I can see there is no way to do the override without hacking core Joomla. This is because the parameters for the item are taken fairly directly from the database, and I can't find any way to intercept these to insert a new parameter value.

Cheers,
Stephen