/**
* Return cached object if exists
*
* @param string $page The name of the page.
* @param string $prefix Prefix to use in class structure.
*
* @return mixed
*/
public static function create_or_null($page, $prefix)
{
static $cache = array();
if (!isset($cache[$prefix])) {
$cache[$prefix] = array();
}
if (!isset($cache[$prefix][$page])) {
$cache[$prefix][$page] = parent::create_or_null($page, $prefix);
}
return $cache[$prefix][$page];
}
/**
* Unified setter function
*
* @param string $type Type of object.
* @param string $page Page name.
* @param mixed|null $handler Handler to apply.
*
* @throws InvalidArgumentException For invalid argument types.
*/
private static function set_settable_handler($type, $page, $handler = null)
{
// Create NullObject for empty handler, i.e. remove functionality.
if (empty($handler)) {
$handler = Stencil_Subclass_Factory::create_null(sprintf(self::CLASS_FORMAT, $type));
}
switch ($type) {
case 'Hierarchy':
if (!is_array($handler) && !$handler instanceof Traversable) {
throw new InvalidArgumentException('Expected $handler to be array or Traversable.');
}
break;
default:
if (!is_callable($handler)) {
throw new InvalidArgumentException('Expected $handler to be callable.');
}
break;
}
self::$handlers[$type][$page] = $handler;
}
