Article: https://hwk.fr/blog/requetes-ajax-cache-statique-mise-jour-intervalle-wordpress

wp-advanced-ajax-static-cache-interval-functions.php

<?php

add_action('wp_ajax_hwk_ajax_template', 'hwk_ajax_template');
add_action('wp_ajax_nopriv_hwk_ajax_template', 'hwk_ajax_template');
function hwk_ajax_template($id = false){
    $configs = apply_filters('hwk_ajax_configs', $configs);
    if(empty($configs))
        return;
    
    $html = hwk_ajax_config($configs, $id);
    
    if(wp_doing_ajax())
        wp_send_json_success($html);
    
    echo $html;
}

function hwk_ajax_config($configs, $id = false){
    if(!$id && wp_doing_ajax() && isset($_POST['id']))
        $id = $_POST['id'];
    
    if(!$id)
        return;
    
    $config = array();
    foreach($configs as $line){
        if($line['id'] != $id)
            continue;
        
        $config = $line;
        break;
    }
    
    return hwk_ajax_get_template($config);
}

function hwk_ajax_get_template($args = array()){
    if(!$args['id'] || !$args['template'])
        return;
    
    $args = wp_parse_args($args, array(
        'id'        => false,
        'template'  => false,
        'cache'     => false,
        'flush'     => false,
        'param'     => false,
        'interval'  => 900,
    ));
    
    if(!$args['param'] && isset($_POST['param']) && !empty($_POST['param']))
        $args['param'] = $_POST['param'];
    
    if($args['param'] && strpos($args['cache'], '%param%'))
        $args['cache'] = str_replace('%param%', $args['param'], $args['cache']);
    
    $file = hwk_ajax_cache_file($args['cache']);
    
    // Fichier de cache: Permission de lecture Ajax
    if($cache = hwk_ajax_cache_read($args, $file))
        return $cache;
    
    // Le fichier de Cache n'existe pas. Il faut le créer
    ob_start();
        
        set_query_var('hwk_ajax_data', $args);
        get_template_part($args['template']);
    
    $page = ob_get_clean();
    
    // Mise à jour du fichier de cache
    file_put_contents($file, $page);
    
    // Pas de Flush de Cache
    if(!$args['flush'])
        return $page;
    
    // WP Super Cache Flush
    if(function_exists('wp_cache_clear_cache')){
        if(is_int($args['flush']))
            wp_cache_post_change($args['flush']);
        else
            wp_cache_clear_cache();
    }
    
    // W3TC Cache Flush
    if(function_exists('w3tc_flush_post')){
        if(is_int($args['flush']))
            w3tc_flush_post($args['flush']);
        else
            w3tc_flush_posts();   
    }
    
    // WP Rocket Cache Flush
    if(function_exists('rocket_clean_post')){
        if(is_int($args['flush']))
            rocket_clean_post($args['flush']);
        else
            rocket_clean_domain();
    }
    
    // Affichage du contenu
    return $page;
}

function hwk_ajax_cache_file($cache){
    return get_template_directory() . '/' . $cache . '.html';
}

function hwk_ajax_cache_read($args, $file){
    if(!file_exists($file))
        return false;
    
    if(wp_doing_ajax() && (filemtime($file) + $args['interval']) < time())
        return false;
    
    return file_get_contents($file);
}

function hwk_ajax_template_data(){
    if(!$args = get_query_var('hwk_ajax_data'))
        return;
    
    echo 'data-hwk-ajax-action-id="' . $args['id'] . '" data-hwk-ajax-ts="' . (time() + $args['interval']) . '" data-hwk-ajax-param="' . $args['param'] . '"';
}