FilterInterface.php

Do whatever processing this filter needs to do. By default it should not return anything during normal execution. However, when an abnormal state is found, it should return an instance of CodeIgniter\HTTP\Response. If it does, script execution will end and that Response will be sent back to the client, allowing for error pages, redirects, etc.

Allows After filters to inspect and modify the response object as needed. This method does not allow any way to stop execution of other after filters, short of throwing an Exception or Error.