When used with the MVC components, Zend_Layout
registers an action controller helper with the helper broker. The
default helper,
Zend_Layout_Controller_Action_Helper_Layout, acts as a
dumb proxy to the layout object instance itself, and should be
suitable for most use cases.
Should you feel the need to write custom functionality, simply write
an action helper class extending
Zend_Controller_Action_Helper_Abstract and pass the
class name as the helperClass option to the
startMvc() method. Details of the implementation are
up to you.