Questions & Answers

I'm writing a plugin that writes the HTML output to the file and loads the site from that file, next time. It works flawlessly. But I can't cache the code after the wp_footer hook. I tried the "shutdown" hook that works after the wp_footer hook but it returns null. I don't know why it is returning null. But I need a hook that runs after the wp_footer hook, where I can cache all the code from 0 to 100.

<?php

$priority = 10;
add_action('template_redirect', function(){
    if(!is_admin() && !is_user_logged_in()){

        $cache_time = get_option('html_cache_time');
        if(empty($cache_time)){
            $cache_time = 60;
        }

        $current_url = get_site_url() . $_SERVER['REQUEST_URI'];

        if(filter_var($current_url, FILTER_SANITIZE_URL)){

            $parsed_url = parse_url($current_url);
            $url_path = isset($parsed_url['path']) ? $parsed_url['path'] : false;

            if(!empty($url_path)){

                $cached_url = NGY_CACHE_DIR . 'app/cached/' .  md5($url_path) . '.cache';

                define('NOGAY_CACHED_URL', $cached_url);
                $end_time = 60 * $cache_time;

                if(file_exists($cached_url)){
                    if(time() - $end_time < filemtime($cached_url)){
                        readfile($cached_url);
                        exit;
                    }else{
                        unlink($cached_url);
                    }
                }

            }
        }
        ob_start();
    }

}, $priority);

add_action('wp_footer', function(){
    if(!is_admin() && !is_user_logged_in()){

        $html = ob_get_clean();
        if(!file_exists(NOGAY_CACHED_URL)){
            echo $html;
        }

        $open_cached_file = fopen(NOGAY_CACHED_URL, 'w+');
        fwrite($open_cached_file, $html);
        fclose($open_cached_file);
        ob_end_flush();
    }
}, PHP_INT_MAX);

I tried another Wordpress hooks. (shutdown)