/**
* Attempts to return a reference to a concrete Horde_Form_Renderer
* instance based on $renderer. It will only create a new instance if no
* Horde_Form_Renderer instance with the same parameters currently exists.
*
* This should be used if multiple types of form renderers (and,
* thus, multiple Horde_Form_Renderer instances) are required.
*
* This method must be invoked as: $var = &Horde_Form_Renderer::singleton()
*
* @param mixed $renderer The type of concrete Horde_Form_Renderer
* subclass to return. The code is dynamically
* included. If $renderer is an array, then we will
* look in $renderer[0]/lib/Form/Renderer/ for the
* subclass implementation named $renderer[1].php.
* @param array $params A hash containing any additional configuration a
* form might need.
*
* @return Horde_Form_Renderer The concrete Horde_Form_Renderer reference,
* or false on an error.
*/
function &singleton($renderer, $params = null)
{
static $instances = array();
$signature = serialize(array($renderer, $params));
if (!isset($instances[$signature])) {
$instances[$signature] = Horde_Form_Renderer::factory($renderer, $params);
}
return $instances[$signature];
}
