How to add custom css class to block wrapper I need to add custom css classes to several blocks (can be blocks from view, or facet api, etc).
Is there a way to do it without creating a template for every block?
It could be useful a theme function, or a hook, that should do something like:

 if ($var == 'block_name') {
   $class_custom = 'my-custom-class';
 }


Is it possible?
You can also use the Block class project for the matter.


  Block Class allows users to add classes to any block through the block's configuration interface. By adding a very short snippet of PHP to a theme's block.tpl.php file, classes can be added to the parent  element of a block. Hooray for more powerful block theming!