woocommerce_get_product_subcategories_cache_key │ filter-hook │ WC 1.0

Usage

add_filter( 'woocommerce_get_product_subcategories_cache_key', 'wp_kama_woocommerce_get_product_subcategories_cache_key_filter', 10, 2 );

/**
 * Function for `woocommerce_get_product_subcategories_cache_key` filter-hook.
 * 
 * @param  $string    
 * @param  $parent_id 
 *
 * @return 
 */
function wp_kama_woocommerce_get_product_subcategories_cache_key_filter( $string, $parent_id ){

	// filter...
	return $string;
}

$string

-

$parent_id

-

Where the hook is called

$cache_key          = apply_filters( 'woocommerce_get_product_subcategories_cache_key', 'product-category-hierarchy-' . $parent_id, $parent_id );

Where the hook is used in WooCommerce