wp_localize_script

function wpflames_localize_files() {
  wp_localize_script('main-js', 'wpflamesData', array(
    'root_url' => get_site_url(),
    'nonce' => wp_create_nonce('wp_rest')
  ));
}
add_action('wp_enqueue_scripts', 'wpflames_localize_files');

This code is a WordPress function named wpflames_localize_files. Its purpose is to provide data to the scripts associated with a WordPress theme or plugin. Here’s a detailed explanation of what it does:

1. wp_localize_script function: This function allows sending data from PHP to JavaScript scripts. In this case, the script named ‘main-js’ receives the data. The wpflamesData is an object that contains two pieces of data:

• 'root_url': Receives the result of get_site_url(), which returns the base URL of the WordPress installation.
• 'nonce': A unique security token created by the wp_create_nonce('wp_rest') function, which can be used in WordPress REST API calls to enhance the security of the site.

1. add_action call: This is part of the WordPress hook system. The wp_enqueue_scripts is a specific event that WordPress triggers when loading scripts and stylesheets. We register our wpflames_localize_files function with this event, so the function runs on every page load.

In summary, this code can be used in a WordPress theme or plugin to make certain PHP-based data accessible to JavaScript, as well as to provide secure methods for using the WordPress REST API.