cache-breaking-route.php

'articles/details/:url_title' => function (\rsanchez\ResourceRouter\Router $router, $wildcard) {

    $ee = ee();
    $ee->load->helper('date');

    $query = $ee->db->select('edit_date')
            ->from('channel_titles')
            ->join('channels', 'channel_titles.channel_id = channels.channel_id')
            ->where('url_title', (string) $wildcard)
            ->where('channel_name', 'articles')
            ->get();

    if(!$query->num_rows) {

        $router->set404();

    } else {

        $ee->config->set_item('send_headers', FALSE);
        $ifModifiedSinceString = $ee->input->server('HTTP_IF_MODIFIED_SINCE');

        $entry = $query->row();
        $lastModifiedTimestamp = mysql_to_unix($entry->edit_date);
        $lastModifiedString = sprintf("%s GMT", gmdate("D, d M Y H:i:s", $lastModifiedTimestamp));

        if($lastModifiedString === $ifModifiedSinceString) {
            header(sprintf('Last-Modified: %s', $lastModifiedString), true, 304);
            $router->output(false);
        } else {
            header(sprintf('Last-Modified: %s', $lastModifiedString), true, 200);
            $router->setTemplate('articles/read');
        }
    }
},