/**
* Get singleton instance for filter
* @param string $filterID
* @return eZFindExtendedAttributeFilterInterface|false
*/
public static function getInstance($filterID)
{
if (!isset(self::$instances[$filterID])) {
try {
if (!self::$filtersList) {
$ini = eZINI::instance('ezfind.ini');
self::$filtersList = $ini->variable('ExtendedAttributeFilters', 'FiltersList');
}
if (!isset(self::$filtersList[$filterID])) {
throw new Exception($filterID . ' extended attribute filter is not defined');
}
$className = self::$filtersList[$filterID];
if (!class_exists($className)) {
throw new Exception('Could not find class ' . $className);
}
$instance = new $className();
if (!$instance instanceof eZFindExtendedAttributeFilterInterface) {
throw new Exception($className . ' is not a valid eZFindExtendedAttributeFilterInterface');
}
self::$instances[$filterID] = $instance;
} catch (Exception $e) {
eZDebug::writeWarning($e->getMessage(), __METHOD__);
self::$instances[$filterID] = false;
}
}
return self::$instances[$filterID];
}
