Determine whether the WooCommerce store is set to be closed or not

woo-store-vacation-check.php

<?php
/**
 * Determine whether the store is set to be closed or not!
 * You can place PHP snippets at the bottom of your child theme `functions.php` file (before "?>" if you have it).
 * 
 * @param  object $wp_admin_bar 
 * @return void
 */
function prefix_is_shop_closed( $wp_admin_bar ) {
    // Bail early, in case the plugin is not activated.
    if ( ! defined( 'WSVPRO_SLUG' ) ) {
    	return;
    }

    // Get the nodes produced by plugins and core.
    $all_toolbar_nodes = $wp_admin_bar->get_nodes();
    // Loop through each node to see if there is one matched with the plugin slug.
    foreach ( $all_toolbar_nodes as $node ) {
    	if ( WSVPRO_SLUG === $node->id ) {
    		echo 'The store is closed!'; // Do something here...
    	}
    }
}
add_action( 'admin_bar_menu', 'prefix_is_shop_closed', PHP_INT_MAX );