<?php
if (!defined('ABSPATH')) {
exit;
}
class WC_Queue
{
protected static $instance = null;
protected static $default_cass = 'WC_Action_Queue';
public static final function instance()
{
if (is_null(self::$instance)) {
$class = self::get_class();
self::$instance = new $class();
self::$instance = self::validate_instance(self::$instance);
}
return self::$instance;
}
protected static function get_class()
{
if (!did_action('plugins_loaded')) {
wc_doing_it_wrong(__FUNCTION__, __('This function should not be called before plugins_loaded.', 'woocommerce'), '3.5.0');
}
return apply_filters('woocommerce_queue_class', self::$default_cass);
}
protected static function validate_instance($instance)
{
if (false === $instance instanceof WC_Queue_Interface) {
$default_class = self::$default_cass;
wc_doing_it_wrong(__FUNCTION__, sprintf(__('The class attached to the "woocommerce_queue_class" does not implement the WC_Queue_Interface interface. The default %s class will be used instead.', 'woocommerce'), $default_class), '3.5.0');
$instance = new $default_class();
}
return $instance;
}
}