engineN/system/Filters/FilterInterface.php

<?php

/**
 * This file is part of CodeIgniter 4 framework.
 *
 * (c) CodeIgniter Foundation <admin@codeigniter.com>
 *
 * For the full copyright and license information, please view
 * the LICENSE file that was distributed with this source code.
 */

namespace CodeIgniter\Filters;

use CodeIgniter\HTTP\RequestInterface;
use CodeIgniter\HTTP\ResponseInterface;

/**
 * Filter interface
 */
interface FilterInterface
{
    /**
     * 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.
     *
     * @param list<string>|null $arguments
     *
     * @return RequestInterface|ResponseInterface|string|void
     */
    public function before(RequestInterface $request, $arguments = null);

    /**
     * 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.
     *
     * @param list<string>|null $arguments
     *
     * @return ResponseInterface|void
     */
    public function after(RequestInterface $request, ResponseInterface $response, $arguments = null);
}