leilukin-tumbleblog/includes/interface/Controller.php

<?php
    /**
     * Interface: Controller
     * Describes the functions required by Controller implementations.
     */
    interface Controller {
        /**
         * Function: parse
         * Route constructor calls this to determine the action.
         */
        public function parse(
            $route
        ): ?string;

        /**
         * Function: exempt
         * Route constructor calls this to determine "view_site" exemptions.
         */
        public function exempt(
            $action
        ): bool;
    }