You can do it as I do, by adding filter to superpwa_sw_template hook. Like this:
to you functions.php

/**
 * Additional urls are passed from external resources to anonymous function
 */
add_filter('superpwa_sw_template', function($template) use ($additional_urls) {
global $urls_list;
$urls_list = is_array($urls_list) ? $urls_list : [];
$urls_list = array_merge($additional_urls, $urls_list);
$pattern = '/(const filesToCache = \[.*)(\];)/';
$replacement = sprintf('\\1%s\\2', count($urls_list) >= 2 ? ', \'' . implode('\',\'', $urls_list) . '\'' : ( count($urls_list) > 0 ? ', ' . $urls_list[0] : ''));
return preg_replace($pattern, $replacement, $template);
});

You can play with internal code part in here:
http://sandbox.onlinephpfunctions.com/code/a370634c6225b7062cecc263be93ede642e4bb11

• This reply was modified 9 months, 3 weeks ago by  juslintek.