public static function load($handle)
{
$pathname = EXTENSIONS . "/{$handle}";
if (!is_array(self::$loaded_extensions)) {
self::$loaded_extensions = array();
}
if (!isset(self::$loaded_extensions[$pathname])) {
if (!file_exists(realpath($pathname) . '/extension.driver.php')) {
throw new ExtensionException('No extension driver found at ' . $pathname);
}
$class = (require_once realpath($pathname) . '/extension.driver.php');
self::$loaded_extensions[$pathname] = $class;
if (is_null(self::$loaded_extensions[$pathname]) || !class_exists(self::$loaded_extensions[$pathname])) {
throw new ExtensionException('Extension driver found at "' . $pathname . '" did not return a valid classname for instantiation.');
}
self::$extensions[$handle] = new self::$loaded_extensions[$pathname]();
self::$extensions_class_to_path[$class] = $pathname;
}
return self::$extensions[$handle];
}
